Repository: facebook/react
Pull request: Extract Fizz instruction set to build macro

We're adding an option to Fizz to support an alternate output format that doesn't rely on inline script tags (see #25437). The two outputs will share the same "instruction set" of functions. These functions are currently inlined into the source file; to maintain a single source of truth, in preparation for the new option, this commit moves the instruction set to a separate file that is injected by the build system, similar to a macro.

In the future, we could improve this further by running Closure on the instruction set instead of hardcoding the output. This isn't an urgent improvement, though, because we rarely modify the instruction set.

Co-authored-by: Mofei Zhang <feifei0@fb.com>

Changed files:
filename: packages/react-dom-bindings/src/server/ReactDOMServerFormatConfig.js
patch: @@ -74,6 +74,11 @@ export {
   hoistResourcesToRoot,
 } from './ReactDOMFloatServer';
 
+import completeSegmentFunction from './fizz-instruction-set/completeSegmentFunctionString';
+import completeBoundaryFunction from './fizz-instruction-set/completeBoundaryFunctionString';
+import styleInsertionFunction from './fizz-instruction-set/styleInsertionFunctionString';
+import clientRenderFunction from './fizz-instruction-set/clientRenderFunctionString';
+
 import ReactDOMSharedInternals from 'shared/ReactDOMSharedInternals';
 const ReactDOMCurrentDispatcher = ReactDOMSharedInternals.Dispatcher;
 
@@ -2021,219 +2026,6 @@ export function writeEndSegment(
   }
 }
 
-// Instruction Set
-
-// The following code is the source scripts that we then minify and inline below,
-// with renamed function names that we hope don't collide:
-
-// const COMMENT_NODE = 8;
-// const SUSPENSE_START_DATA = '$';
-// const SUSPENSE_END_DATA = '/$';
-// const SUSPENSE_PENDING_START_DATA = '$?';
-// const SUSPENSE_FALLBACK_START_DATA = '$!';
-// const LOADED = 'l';
-// const ERRORED = 'e';
-
-// function clientRenderBoundary(suspenseBoundaryID, errorDigest, errorMsg, errorComponentStack) {
-//   // Find the fallback's first element.
-//   const suspenseIdNode = document.getElementById(suspenseBoundaryID);
-//   if (!suspenseIdNode) {
-//     // The user must have already navigated away from this tree.
-//     // E.g. because the parent was hydrated.
-//     return;
-//   }
-//   // Find the boundary around the fallback. This is always the previous node.
-//   const suspenseNode = suspenseIdNode.previousSibling;
-//   // Tag it to be client rendered.
-//   suspenseNode.data = SUSPENSE_FALLBACK_START_DATA;
-//   // assign error metadata to first sibling
-//   let dataset = suspenseIdNode.dataset;
-//   if (errorDigest) dataset.dgst = errorDigest;
-//   if (errorMsg) dataset.msg = errorMsg;
-//   if (errorComponentStack) dataset.stck = errorComponentStack;
-//   // Tell React to retry it if the parent already hydrated.
-//   if (suspenseNode._reactRetry) {
-//     suspenseNode._reactRetry();
-//   }
-// }
-
-// resourceMap = new Map();
-// function completeBoundaryWithStyles(suspenseBoundaryID, contentID, styles) {
-//   const precedences = new Map();
-//   const thisDocument = document;
-//   let lastResource, node;
-
-//   // Seed the precedence list with existing resources
-//   let nodes = thisDocument.querySelectorAll('link[data-rprec]');
-//   for (let i = 0;node = nodes[i++];) {
-//     precedences.set(node.dataset.rprec, lastResource = node);
-//   }
-
-//   let i = 0;
-//   let dependencies = [];
-//   let style, href, precedence, attr, loadingState, resourceEl;
-
-//   function setStatus(s) {
-//     this.s = s;
-//   }
-
-//   while (style = styles[i++]) {
-//     let j = 0;
-//     href = style[j++];
-//     // We check if this resource is already in our resourceMap and reuse it if so.
-//     // If it is already loaded we don't return it as a depenendency since there is nothing
-//     // to wait for
-//     loadingState = resourceMap.get(href);
-//     if (loadingState) {
-//       if (loadingState.s !== 'l') {
-//         dependencies.push(loadingState);
-//       }
-//       continue;
-//     }
-
-//     // We construct our new resource element, looping over remaining attributes if any
-//     // setting them to the Element.
-//     resourceEl = thisDocument.createElement("link");
-//     resourceEl.href = href;
-//     resourceEl.rel = 'stylesheet';
-//     resourceEl.dataset.rprec = precedence = style[j++];
-//     while(attr = style[j++]) {
-//       resourceEl.setAttribute(attr, style[j++]);
-//     }
-
-//     // We stash a pending promise in our map by href which will resolve or reject
-//     // when the underlying resource loads or errors. We add it to the dependencies
-//     // array to be returned.
-//     loadingState = resourceEl._p = new Promise((re, rj) => {
-//       resourceEl.onload = re;
-//       resourceEl.onerror = rj;
-//     })
-//     loadingState.then(
-//       setStatus.bind(loadingState, LOADED),
-//       setStatus.bind(loadingState, ERRORED)
-//     );
-//     resourceMap.set(href, loadingState);
-//     dependencies.push(loadingState);
-
-//     // The prior style resource is the last one placed at a given
-//     // precedence or the last resource itself which may be null.
-//     // We grab this value and then update the last resource for this
-//     // precedence to be the inserted element, updating the lastResource
-//     // pointer if needed.
-//     let prior = precedences.get(precedence) || lastResource;
-//     if (prior === lastResource) {
-//       lastResource = resourceEl
-//     }
-//     precedences.set(precedence, resourceEl)
-
-//     // Finally, we insert the newly constructed instance at an appropriate location
-//     // in the Document.
-//     if (prior) {
-//       prior.parentNode.insertBefore(resourceEl, prior.nextSibling);
-//     } else {
-//       let head = thisDocument.head;
-//       head.insertBefore(resourceEl, head.firstChild);
-//     }
-//   }
-
-//   Promise.all(dependencies).then(
-//     completeBoundary.bind(null, suspenseBoundaryID, contentID, ''),
-//     completeBoundary.bind(null, suspenseBoundaryID, contentID, "Resource failed to load")
-//   );
-// }
-
-// function completeBoundary(suspenseBoundaryID, contentID, errorDigest) {
-//   const contentNode = document.getElementById(contentID);
-//   // We'll detach the content node so that regardless of what happens next we don't leave in the tree.
-//   // This might also help by not causing recalcing each time we move a child from here to the target.
-//   contentNode.parentNode.removeChild(contentNode);
-
-//   // Find the fallback's first element.
-//   const suspenseIdNode = document.getElementById(suspenseBoundaryID);
-//   if (!suspenseIdNode) {
-//     // The user must have already navigated away from this tree.
-//     // E.g. because the parent was hydrated. That's fine there's nothing to do
-//     // but we have to make sure that we already deleted the container node.
-//     return;
-//   }
-//   // Find the boundary around the fallback. This is always the previous node.
-//   const suspenseNode = suspenseIdNode.previousSibling;
-
-//   if (!errorDigest) {
-//     // Clear all the existing children. This is complicated because
-//     // there can be embedded Suspense boundaries in the fallback.
-//     // This is similar to clearSuspenseBoundary in ReactDOMHostConfig.
-//     // TODO: We could avoid this if we never emitted suspense boundaries in fallback trees.
-//     // They never hydrate anyway. However, currently we support incrementally loading the fallback.
-//     const parentInstance = suspenseNode.parentNode;
-//     let node = suspenseNode.nextSibling;
-//     let depth = 0;
-//     do {
-//       if (node && node.nodeType === COMMENT_NODE) {
-//         const data = node.data;
-//         if (data === SUSPENSE_END_DATA) {
-//           if (depth === 0) {
-//             break;
-//           } else {
-//             depth--;
-//           }
-//         } else if (
-//           data === SUSPENSE_START_DATA ||
-//           data === SUSPENSE_PENDING_START_DATA ||
-//           data === SUSPENSE_FALLBACK_START_DATA
-//         ) {
-//           depth++;
-//         }
-//       }
-
-//       const nextNode = node.nextSibling;
-//       parentInstance.removeChild(node);
-//       node = nextNode;
-//     } while (node);
-
-//     const endOfBoundary = node;
-
-//     // Insert all the children from the contentNode between the start and end of suspense boundary.
-//     while (contentNode.firstChild) {
-//       parentInstance.insertBefore(contentNode.firstChild, endOfBoundary);
-//     }
-
-//     suspenseNode.data = SUSPENSE_START_DATA;
-//   } else {
-//     suspenseNode.data = SUSPENSE_FALLBACK_START_DATA;
-//     suspenseIdNode.setAttribute('data-dgst', errorDigest)
-//   }
-
-//   if (suspenseNode._reactRetry) {
-//     suspenseNode._reactRetry();
-//   }
-// }
-
-// function completeSegment(containerID, placeholderID) {
-//   const segmentContainer = document.getElementById(containerID);
-//   const placeholderNode = document.getElementById(placeholderID);
-//   // We always expect both nodes to exist here because, while we might
-//   // have navigated away from the main tree, we still expect the detached
-//   // tree to exist.
-//   segmentContainer.parentNode.removeChild(segmentContainer);
-//   while (segmentContainer.firstChild) {
-//     placeholderNode.parentNode.insertBefore(
-//       segmentContainer.firstChild,
-//       placeholderNode,
-//     );
-//   }
-//   placeholderNode.parentNode.removeChild(placeholderNode);
-// }
-
-const completeSegmentFunction =
-  'function $RS(a,b){a=document.getElementById(a);b=document.getElementById(b);for(a.parentNode.removeChild(a);a.firstChild;)b.parentNode.insertBefore(a.firstChild,b);b.parentNode.removeChild(b)}';
-const completeBoundaryFunction =
-  'function $RC(b,c,d){c=document.getElementById(c);c.parentNode.removeChild(c);var a=document.getElementById(b);if(a){b=a.previousSibling;if(d)b.data="$!",a.setAttribute("data-dgst",d);else{d=b.parentNode;a=b.nextSibling;var e=0;do{if(a&&a.nodeType===8){var h=a.data;if(h==="/$")if(0===e)break;else e--;else h!=="$"&&h!=="$?"&&h!=="$!"||e++}h=a.nextSibling;d.removeChild(a);a=h}while(a);for(;c.firstChild;)d.insertBefore(c.firstChild,a);b.data="$"}b._reactRetry&&b._reactRetry()}}';
-const styleInsertionFunction =
-  '$RM=new Map;function $RR(p,q,t){function r(l){this.s=l}for(var m=new Map,n=document,g,e,f=n.querySelectorAll("link[data-rprec]"),d=0;e=f[d++];)m.set(e.dataset.rprec,g=e);e=0;f=[];for(var c,h,b,a;c=t[e++];){var k=0;h=c[k++];if(b=$RM.get(h))"l"!==b.s&&f.push(b);else{a=n.createElement("link");a.href=h;a.rel="stylesheet";for(a.dataset.rprec=d=c[k++];b=c[k++];)a.setAttribute(b,c[k++]);b=a._p=new Promise(function(l,u){a.onload=l;a.onerror=u});b.then(r.bind(b,"l"),r.bind(b,"e"));$RM.set(h,b);f.push(b);c=m.get(d)||g;c===g&&(g=a);m.set(d,a);c?c.parentNode.insertBefore(a,c.nextSibling):(d=n.head,d.insertBefore(a,d.firstChild))}}Promise.all(f).then($RC.bind(null,p,q,""),$RC.bind(null,p,q,"Resource failed to load"))}';
-const clientRenderFunction =
-  'function $RX(b,c,d,e){var a=document.getElementById(b);a&&(b=a.previousSibling,b.data="$!",a=a.dataset,c&&(a.dgst=c),d&&(a.msg=d),e&&(a.stck=e),b._reactRetry&&b._reactRetry())}';
-
 const completeSegmentScript1Full = stringToPrecomputedChunk(
   completeSegmentFunction + ';$RS("',
 );

filename: packages/react-dom-bindings/src/server/fizz-instruction-set/clientRenderFunctionString.js
patch: @@ -0,0 +1,38 @@
+// Instruction Set
+
+// The following code is the source scripts that we then minify and inline below,
+// with renamed function names that we hope don't collide:
+
+// const COMMENT_NODE = 8;
+// const SUSPENSE_START_DATA = '$';
+// const SUSPENSE_END_DATA = '/$';
+// const SUSPENSE_PENDING_START_DATA = '$?';
+// const SUSPENSE_FALLBACK_START_DATA = '$!';
+// const LOADED = 'l';
+// const ERRORED = 'e';
+
+// function clientRenderBoundary(suspenseBoundaryID, errorDigest, errorMsg, errorComponentStack) {
+//   // Find the fallback's first element.
+//   const suspenseIdNode = document.getElementById(suspenseBoundaryID);
+//   if (!suspenseIdNode) {
+//     // The user must have already navigated away from this tree.
+//     // E.g. because the parent was hydrated.
+//     return;
+//   }
+//   // Find the boundary around the fallback. This is always the previous node.
+//   const suspenseNode = suspenseIdNode.previousSibling;
+//   // Tag it to be client rendered.
+//   suspenseNode.data = SUSPENSE_FALLBACK_START_DATA;
+//   // assign error metadata to first sibling
+//   let dataset = suspenseIdNode.dataset;
+//   if (errorDigest) dataset.dgst = errorDigest;
+//   if (errorMsg) dataset.msg = errorMsg;
+//   if (errorComponentStack) dataset.stck = errorComponentStack;
+//   // Tell React to retry it if the parent already hydrated.
+//   if (suspenseNode._reactRetry) {
+//     suspenseNode._reactRetry();
+//   }
+// }
+
+// TODO: Generate this file with a build step.
+export default 'function $RX(b,c,d,e){var a=document.getElementById(b);a&&(b=a.previousSibling,b.data="$!",a=a.dataset,c&&(a.dgst=c),d&&(a.msg=d),e&&(a.stck=e),b._reactRetry&&b._reactRetry())}';

filename: packages/react-dom-bindings/src/server/fizz-instruction-set/completeBoundaryFunctionString.js
patch: @@ -0,0 +1,82 @@
+// Instruction Set
+
+// The following code is the source scripts that we then minify and inline below,
+// with renamed function names that we hope don't collide:
+
+// const COMMENT_NODE = 8;
+// const SUSPENSE_START_DATA = '$';
+// const SUSPENSE_END_DATA = '/$';
+// const SUSPENSE_PENDING_START_DATA = '$?';
+// const SUSPENSE_FALLBACK_START_DATA = '$!';
+// const LOADED = 'l';
+// const ERRORED = 'e';
+
+// function completeBoundary(suspenseBoundaryID, contentID, errorDigest) {
+//   const contentNode = document.getElementById(contentID);
+//   // We'll detach the content node so that regardless of what happens next we don't leave in the tree.
+//   // This might also help by not causing recalcing each time we move a child from here to the target.
+//   contentNode.parentNode.removeChild(contentNode);
+
+//   // Find the fallback's first element.
+//   const suspenseIdNode = document.getElementById(suspenseBoundaryID);
+//   if (!suspenseIdNode) {
+//     // The user must have already navigated away from this tree.
+//     // E.g. because the parent was hydrated. That's fine there's nothing to do
+//     // but we have to make sure that we already deleted the container node.
+//     return;
+//   }
+//   // Find the boundary around the fallback. This is always the previous node.
+//   const suspenseNode = suspenseIdNode.previousSibling;
+
+//   if (!errorDigest) {
+//     // Clear all the existing children. This is complicated because
+//     // there can be embedded Suspense boundaries in the fallback.
+//     // This is similar to clearSuspenseBoundary in ReactDOMHostConfig.
+//     // TODO: We could avoid this if we never emitted suspense boundaries in fallback trees.
+//     // They never hydrate anyway. However, currently we support incrementally loading the fallback.
+//     const parentInstance = suspenseNode.parentNode;
+//     let node = suspenseNode.nextSibling;
+//     let depth = 0;
+//     do {
+//       if (node && node.nodeType === COMMENT_NODE) {
+//         const data = node.data;
+//         if (data === SUSPENSE_END_DATA) {
+//           if (depth === 0) {
+//             break;
+//           } else {
+//             depth--;
+//           }
+//         } else if (
+//           data === SUSPENSE_START_DATA ||
+//           data === SUSPENSE_PENDING_START_DATA ||
+//           data === SUSPENSE_FALLBACK_START_DATA
+//         ) {
+//           depth++;
+//         }
+//       }
+
+//       const nextNode = node.nextSibling;
+//       parentInstance.removeChild(node);
+//       node = nextNode;
+//     } while (node);
+
+//     const endOfBoundary = node;
+
+//     // Insert all the children from the contentNode between the start and end of suspense boundary.
+//     while (contentNode.firstChild) {
+//       parentInstance.insertBefore(contentNode.firstChild, endOfBoundary);
+//     }
+
+//     suspenseNode.data = SUSPENSE_START_DATA;
+//   } else {
+//     suspenseNode.data = SUSPENSE_FALLBACK_START_DATA;
+//     suspenseIdNode.setAttribute('data-dgst', errorDigest)
+//   }
+
+//   if (suspenseNode._reactRetry) {
+//     suspenseNode._reactRetry();
+//   }
+// }
+
+// TODO: Generate this file with a build step.
+export default 'function $RC(b,c,d){c=document.getElementById(c);c.parentNode.removeChild(c);var a=document.getElementById(b);if(a){b=a.previousSibling;if(d)b.data="$!",a.setAttribute("data-dgst",d);else{d=b.parentNode;a=b.nextSibling;var e=0;do{if(a&&a.nodeType===8){var h=a.data;if(h==="/$")if(0===e)break;else e--;else h!=="$"&&h!=="$?"&&h!=="$!"||e++}h=a.nextSibling;d.removeChild(a);a=h}while(a);for(;c.firstChild;)d.insertBefore(c.firstChild,a);b.data="$"}b._reactRetry&&b._reactRetry()}}';

filename: packages/react-dom-bindings/src/server/fizz-instruction-set/completeSegmentFunctionString.js
patch: @@ -0,0 +1,31 @@
+// Instruction Set
+
+// The following code is the source scripts that we then minify and inline below,
+// with renamed function names that we hope don't collide:
+
+// const COMMENT_NODE = 8;
+// const SUSPENSE_START_DATA = '$';
+// const SUSPENSE_END_DATA = '/$';
+// const SUSPENSE_PENDING_START_DATA = '$?';
+// const SUSPENSE_FALLBACK_START_DATA = '$!';
+// const LOADED = 'l';
+// const ERRORED = 'e';
+
+// function completeSegment(containerID, placeholderID) {
+//   const segmentContainer = document.getElementById(containerID);
+//   const placeholderNode = document.getElementById(placeholderID);
+//   // We always expect both nodes to exist here because, while we might
+//   // have navigated away from the main tree, we still expect the detached
+//   // tree to exist.
+//   segmentContainer.parentNode.removeChild(segmentContainer);
+//   while (segmentContainer.firstChild) {
+//     placeholderNode.parentNode.insertBefore(
+//       segmentContainer.firstChild,
+//       placeholderNode,
+//     );
+//   }
+//   placeholderNode.parentNode.removeChild(placeholderNode);
+// }
+
+// TODO: Generate this file with a build step.
+export default 'function $RS(a,b){a=document.getElementById(a);b=document.getElementById(b);for(a.parentNode.removeChild(a);a.firstChild;)b.parentNode.insertBefore(a.firstChild,b);b.parentNode.removeChild(b)}';

filename: packages/react-dom-bindings/src/server/fizz-instruction-set/styleInsertionFunctionString.js
patch: @@ -0,0 +1,100 @@
+// Instruction Set
+
+// The following code is the source scripts that we then minify and inline below,
+// with renamed function names that we hope don't collide:
+
+// const COMMENT_NODE = 8;
+// const SUSPENSE_START_DATA = '$';
+// const SUSPENSE_END_DATA = '/$';
+// const SUSPENSE_PENDING_START_DATA = '$?';
+// const SUSPENSE_FALLBACK_START_DATA = '$!';
+// const LOADED = 'l';
+// const ERRORED = 'e';
+
+// resourceMap = new Map();
+// function completeBoundaryWithStyles(suspenseBoundaryID, contentID, styles) {
+//   const precedences = new Map();
+//   const thisDocument = document;
+//   let lastResource, node;
+
+//   // Seed the precedence list with existing resources
+//   let nodes = thisDocument.querySelectorAll('link[data-rprec]');
+//   for (let i = 0;node = nodes[i++];) {
+//     precedences.set(node.dataset.rprec, lastResource = node);
+//   }
+
+//   let i = 0;
+//   let dependencies = [];
+//   let style, href, precedence, attr, loadingState, resourceEl;
+
+//   function setStatus(s) {
+//     this.s = s;
+//   }
+
+//   while (style = styles[i++]) {
+//     let j = 0;
+//     href = style[j++];
+//     // We check if this resource is already in our resourceMap and reuse it if so.
+//     // If it is already loaded we don't return it as a depenendency since there is nothing
+//     // to wait for
+//     loadingState = resourceMap.get(href);
+//     if (loadingState) {
+//       if (loadingState.s !== 'l') {
+//         dependencies.push(loadingState);
+//       }
+//       continue;
+//     }
+
+//     // We construct our new resource element, looping over remaining attributes if any
+//     // setting them to the Element.
+//     resourceEl = thisDocument.createElement("link");
+//     resourceEl.href = href;
+//     resourceEl.rel = 'stylesheet';
+//     resourceEl.dataset.rprec = precedence = style[j++];
+//     while(attr = style[j++]) {
+//       resourceEl.setAttribute(attr, style[j++]);
+//     }
+
+//     // We stash a pending promise in our map by href which will resolve or reject
+//     // when the underlying resource loads or errors. We add it to the dependencies
+//     // array to be returned.
+//     loadingState = resourceEl._p = new Promise((re, rj) => {
+//       resourceEl.onload = re;
+//       resourceEl.onerror = rj;
+//     })
+//     loadingState.then(
+//       setStatus.bind(loadingState, LOADED),
+//       setStatus.bind(loadingState, ERRORED)
+//     );
+//     resourceMap.set(href, loadingState);
+//     dependencies.push(loadingState);
+
+//     // The prior style resource is the last one placed at a given
+//     // precedence or the last resource itself which may be null.
+//     // We grab this value and then update the last resource for this
+//     // precedence to be the inserted element, updating the lastResource
+//     // pointer if needed.
+//     let prior = precedences.get(precedence) || lastResource;
+//     if (prior === lastResource) {
+//       lastResource = resourceEl
+//     }
+//     precedences.set(precedence, resourceEl)
+
+//     // Finally, we insert the newly constructed instance at an appropriate location
+//     // in the Document.
+//     if (prior) {
+//       prior.parentNode.insertBefore(resourceEl, prior.nextSibling);
+//     } else {
+//       let head = thisDocument.head;
+//       head.insertBefore(resourceEl, head.firstChild);
+//     }
+//   }
+
+//   Promise.all(dependencies).then(
+//     completeBoundary.bind(null, suspenseBoundaryID, contentID, ''),
+//     completeBoundary.bind(null, suspenseBoundaryID, contentID, "Resource failed to load")
+//   );
+// }
+
+// TODO: Generate this file with a build step.
+export default '$RM=new Map;function $RR(p,q,t){function r(l){this.s=l}for(var m=new Map,n=document,g,e,f=n.querySelectorAll("link[data-rprec]"),d=0;e=f[d++];)m.set(e.dataset.rprec,g=e);e=0;f=[];for(var c,h,b,a;c=t[e++];){var k=0;h=c[k++];if(b=$RM.get(h))"l"!==b.s&&f.push(b);else{a=n.createElement("link");a.href=h;a.rel="stylesheet";for(a.dataset.rprec=d=c[k++];b=c[k++];)a.setAttribute(b,c[k++]);b=a._p=new Promise(function(l,u){a.onload=l;a.onerror=u});b.then(r.bind(b,"l"),r.bind(b,"e"));$RM.set(h,b);f.push(b);c=m.get(d)||g;c===g&&(g=a);m.set(d,a);c?c.parentNode.insertBefore(a,c.nextSibling):(d=n.head,d.insertBefore(a,d.firstChild))}}Promise.all(f).then($RC.bind(null,p,q,""),$RC.bind(null,p,q,"Resource failed to load"))}';