Repository: vuejs/eslint-plugin-vue (JavaScript)

Issue:
vue/attribute-hyphenation doesn't work on <slot> element
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  is not related with your code editor configuration.
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**Checklist**

- [x] I have tried restarting my IDE and the issue persists.
- [x] I have read the [FAQ](https://eslint.vuejs.org/user-guide/#faq) and my problem is not listed.
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**Tell us about your environment**

- **ESLint version:** 8.9.0
- **eslint-plugin-vue version:** 8.5.0
- **Node version:** 16.14.0
- **Operating System:** Windows 11 21H1 22000.493 - (WSL) Ubuntu 20.04.3 LTS(Kernel: 5.10.93.2-microsoft-standard-WSL2)

**Please show your full configuration:**
<!-- Paste content of your .eslintrc file -->
```js
/* eslint-env node */
module.exports = {
  root: true,
  extends: [
    "plugin:vue/vue3-recommended",
    "eslint:recommended"
  ],
  env: {
    "vue/setup-compiler-macros": true,
  },
};
```

**What did you do?**	
<!-- Please include the actual source code causing the issue. -->
```vue
<template>
  <div style="color: red;">
    <slot camelCase withValue="foo" :withBind="1" fooBar-BAZ_QuX />
  </div>
</template>
```

**What did you expect to happen?**
I expect warnings like this to appear:
> Attribute 'withVariableBind' must be hyphenated. eslint(vue/attribute-hyphenation)

**What actually happened?**
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Nothing happens.

**Repository to reproduce this issue**
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https://github.com/yusufkandemir/eslint-plugin-vue-slot-issue


Might be related to https://github.com/vuejs/eslint-plugin-vue/commit/602d80faad9b6004d040209c41fba68e062891d2

`<slot>` is a native HTML element(_related to Web Components_), but the rule should also run on that, just like it used to do before.


Discussion:

Patch:
diff --git a/lib/rules/attribute-hyphenation.js b/lib/rules/attribute-hyphenation.js
index ec5a3a9ab..f9126a548 100644
--- a/lib/rules/attribute-hyphenation.js
+++ b/lib/rules/attribute-hyphenation.js
@@ -106,7 +106,11 @@ module.exports = {
 
     return utils.defineTemplateBodyVisitor(context, {
       VAttribute(node) {
-        if (!utils.isCustomComponent(node.parent.parent)) return
+        if (
+          !utils.isCustomComponent(node.parent.parent) &&
+          node.parent.parent.name !== 'slot'
+        )
+          return
 
         const name = !node.directive
           ? node.key.rawName


Test patch:
diff --git a/tests/lib/rules/attribute-hyphenation.js b/tests/lib/rules/attribute-hyphenation.js
index 7e7f2ea9d..26f9531cb 100644
--- a/tests/lib/rules/attribute-hyphenation.js
+++ b/tests/lib/rules/attribute-hyphenation.js
@@ -56,6 +56,16 @@ ruleTester.run('attribute-hyphenation', rule, {
       filename: 'test.vue',
       code: '<template><my-component :[foo-bar]></my-component></template>',
       options: ['never']
+    },
+    {
+      filename: 'test.vue',
+      code: '<template><div><slot my-prop></slot></div></template>',
+      options: ['always']
+    },
+    {
+      filename: 'test.vue',
+      code: '<template><div><slot myProp></slot></div></template>',
+      options: ['never']
     }
   ],
 
@@ -252,6 +262,32 @@ ruleTester.run('attribute-hyphenation', rule, {
           line: 3
         }
       ]
+    },
+    {
+      filename: 'test.vue',
+      code: '<template><div><slot my-prop="foo"></slot></div></template>',
+      output: '<template><div><slot myProp="foo"></slot></div></template>',
+      options: ['never'],
+      errors: [
+        {
+          message: "Attribute 'my-prop' can't be hyphenated.",
+          type: 'VIdentifier',
+          line: 1
+        }
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: '<template><div><slot MyProp="Bar"></slot></div></template>',
+      output: '<template><div><slot my-prop="Bar"></slot></div></template>',
+      options: ['always'],
+      errors: [
+        {
+          message: "Attribute 'MyProp' must be hyphenated.",
+          type: 'VIdentifier',
+          line: 1
+        }
+      ]
     }
   ]
 })