[compiler] Handle empty list of eslint suppression rules

.codesandbox/ci.json

@@ -1,7 +1,7 @@
 {
   "packages": ["packages/react", "packages/react-dom", "packages/react-server-dom-webpack", "packages/scheduler"],
   "buildCommand": "download-build-in-codesandbox-ci",
-  "node": "20",
+  "node": "18",
   "publishDirectory": {
     "react": "build/oss-experimental/react",
     "react-dom": "build/oss-experimental/react-dom",

compiler/apps/playground/components/Editor/ConfigEditor.tsx

@@ -6,51 +6,52 @@
  */
 
 import MonacoEditor, {loader, type Monaco} from '@monaco-editor/react';
+import {parseConfigPragmaAsString} from 'babel-plugin-react-compiler';
 import type {editor} from 'monaco-editor';
 import * as monaco from 'monaco-editor';
-import {useState} from 'react';
+import parserBabel from 'prettier/plugins/babel';
+import * as prettierPluginEstree from 'prettier/plugins/estree';
+import * as prettier from 'prettier/standalone';
+import {useState, useEffect} from 'react';
 import {Resizable} from 're-resizable';
-import {useStore, useStoreDispatch} from '../StoreContext';
+import {useStore} from '../StoreContext';
 import {monacoOptions} from './monacoOptions';
-import {
-  generateOverridePragmaFromConfig,
-  updateSourceWithOverridePragma,
-} from '../../lib/configUtils';
 
 loader.config({monaco});
 
 export default function ConfigEditor(): JSX.Element {
   const [, setMonaco] = useState<Monaco | null>(null);
   const store = useStore();
-  const dispatchStore = useStoreDispatch();
 
-  const handleChange: (value: string | undefined) => void = async value => {
-    if (value === undefined) return;
+  // Parse string-based override config from pragma comment and format it
+  const [configJavaScript, setConfigJavaScript] = useState('');
 
-    try {
-      const newPragma = await generateOverridePragmaFromConfig(value);
-      const updatedSource = updateSourceWithOverridePragma(
-        store.source,
-        newPragma,
-      );
+  useEffect(() => {
+    const pragma = store.source.substring(0, store.source.indexOf('\n'));
+    const configString = `(${parseConfigPragmaAsString(pragma)})`;
 
-      // Update the store with both the new config and updated source
-      dispatchStore({
-        type: 'updateFile',
-        payload: {
-          source: updatedSource,
-          config: value,
-        },
+    prettier
+      .format(configString, {
+        semi: true,
+        parser: 'babel-ts',
+        plugins: [parserBabel, prettierPluginEstree],
+      })
+      .then(formatted => {
+        setConfigJavaScript(formatted);
+      })
+      .catch(error => {
+        console.error('Error formatting config:', error);
+        setConfigJavaScript('({})'); // Return empty object if not valid for now
+        //TODO: Add validation and error handling for config
       });
-    } catch (_) {
-      dispatchStore({
-        type: 'updateFile',
-        payload: {
-          source: store.source,
-          config: value,
-        },
-      });
-    }
+    console.log('Config:', configString);
+  }, [store.source]);
+
+  const handleChange: (value: string | undefined) => void = value => {
+    if (!value) return;
+
+    // TODO: Implement sync logic to update pragma comments in the source
+    console.log('Config changed:', value);
   };
 
   const handleMount: (
@@ -80,11 +81,12 @@ export default function ConfigEditor(): JSX.Element {
         <MonacoEditor
           path={'config.js'}
           language={'javascript'}
-          value={store.config}
+          value={configJavaScript}
           onMount={handleMount}
           onChange={handleChange}
           options={{
             ...monacoOptions,
+            readOnly: true,
             lineNumbers: 'off',
             folding: false,
             renderLineHighlight: 'none',

compiler/apps/playground/components/Editor/EditorImpl.tsx

@@ -48,7 +48,6 @@ import {
 import {transformFromAstSync} from '@babel/core';
 import {LoggerEvent} from 'babel-plugin-react-compiler/dist/Entrypoint';
 import {useSearchParams} from 'next/navigation';
-import {parseAndFormatConfig} from '../../lib/configUtils';
 
 function parseInput(
   input: string,
@@ -316,17 +315,9 @@ export default function Editor(): JSX.Element {
       });
       mountStore = defaultStore;
     }
-
-    parseAndFormatConfig(mountStore.source).then(config => {
-      dispatchStore({
-        type: 'setStore',
-        payload: {
-          store: {
-            ...mountStore,
-            config,
-          },
-        },
-      });
+    dispatchStore({
+      type: 'setStore',
+      payload: {store: mountStore},
     });
   });
 

compiler/apps/playground/components/Editor/Input.tsx

@@ -17,7 +17,6 @@ import {useStore, useStoreDispatch} from '../StoreContext';
 import {monacoOptions} from './monacoOptions';
 // @ts-expect-error TODO: Make TS recognize .d.ts files, in addition to loading them with webpack.
 import React$Types from '../../node_modules/@types/react/index.d.ts';
-import {parseAndFormatConfig} from '../../lib/configUtils.ts';
 
 loader.config({monaco});
 
@@ -80,17 +79,13 @@ export default function Input({errors, language}: Props): JSX.Element {
     });
   }, [monaco, language]);
 
-  const handleChange: (value: string | undefined) => void = async value => {
+  const handleChange: (value: string | undefined) => void = value => {
     if (!value) return;
 
-    // Parse and format the config
-    const config = await parseAndFormatConfig(value);
-
     dispatchStore({
       type: 'updateFile',
       payload: {
         source: value,
-        config,
       },
     });
   };

compiler/apps/playground/components/StoreContext.tsx

@@ -56,7 +56,6 @@ type ReducerAction =
       type: 'updateFile';
       payload: {
         source: string;
-        config?: string;
       };
     };
 
@@ -67,11 +66,10 @@ function storeReducer(store: Store, action: ReducerAction): Store {
       return newStore;
     }
     case 'updateFile': {
-      const {source, config} = action.payload;
+      const {source} = action.payload;
       const newStore = {
         ...store,
         source,
-        config,
       };
       return newStore;
     }

compiler/apps/playground/lib/configUtils.ts

@@ -1,87 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import parserBabel from 'prettier/plugins/babel';
-import prettierPluginEstree from 'prettier/plugins/estree';
-import * as prettier from 'prettier/standalone';
-import {parseConfigPragmaAsString} from '../../../packages/babel-plugin-react-compiler/src/Utils/TestUtils';
-
-/**
- * Parse config from pragma and format it with prettier
- */
-export async function parseAndFormatConfig(source: string): Promise<string> {
-  const pragma = source.substring(0, source.indexOf('\n'));
-  let configString = parseConfigPragmaAsString(pragma);
-  if (configString !== '') {
-    configString = `(${configString})`;
-  }
-
-  try {
-    const formatted = await prettier.format(configString, {
-      semi: true,
-      parser: 'babel-ts',
-      plugins: [parserBabel, prettierPluginEstree],
-    });
-    return formatted;
-  } catch (error) {
-    console.error('Error formatting config:', error);
-    return ''; // Return empty string if not valid for now
-  }
-}
-
-function extractCurlyBracesContent(input: string): string {
-  const startIndex = input.indexOf('{');
-  const endIndex = input.lastIndexOf('}');
-  if (startIndex === -1 || endIndex === -1 || endIndex <= startIndex) {
-    throw new Error('No outer curly braces found in input');
-  }
-  return input.slice(startIndex, endIndex + 1);
-}
-
-function cleanContent(content: string): string {
-  return content
-    .replace(/[\r\n]+/g, ' ')
-    .replace(/\s+/g, ' ')
-    .trim();
-}
-
-/**
- * Generate a the override pragma comment from a formatted config object string
- */
-export async function generateOverridePragmaFromConfig(
-  formattedConfigString: string,
-): Promise<string> {
-  const content = extractCurlyBracesContent(formattedConfigString);
-  const cleanConfig = cleanContent(content);
-
-  // Format the config to ensure it's valid
-  await prettier.format(`(${cleanConfig})`, {
-    semi: false,
-    parser: 'babel-ts',
-    plugins: [parserBabel, prettierPluginEstree],
-  });
-
-  return `// @OVERRIDE:${cleanConfig}`;
-}
-
-/**
- * Update the override pragma comment in source code.
- */
-export function updateSourceWithOverridePragma(
-  source: string,
-  newPragma: string,
-): string {
-  const firstLineEnd = source.indexOf('\n');
-  const firstLine = source.substring(0, firstLineEnd);
-
-  const pragmaRegex = /^\/\/\s*@/;
-  if (firstLineEnd !== -1 && pragmaRegex.test(firstLine.trim())) {
-    return newPragma + source.substring(firstLineEnd);
-  } else {
-    return newPragma + '\n' + source;
-  }
-}

compiler/apps/playground/lib/defaultStore.ts

@@ -15,10 +15,8 @@ export default function MyApp() {
 
 export const defaultStore: Store = {
   source: index,
-  config: '',
 };
 
 export const emptyStore: Store = {
   source: '',
-  config: '',
 };

compiler/apps/playground/lib/stores/store.ts

@@ -17,7 +17,6 @@ import {defaultStore} from '../defaultStore';
  */
 export interface Store {
   source: string;
-  config?: string;
 }
 export function encodeStore(store: Store): string {
   return compressToEncodedURIComponent(JSON.stringify(store));
@@ -66,14 +65,5 @@ export function initStoreFromUrlOrLocalStorage(): Store {
   const raw = decodeStore(encodedSource);
 
   invariant(isValidStore(raw), 'Invalid Store');
-
-  // Add config property if missing for backwards compatibility
-  if (!('config' in raw)) {
-    return {
-      ...raw,
-      config: '',
-    };
-  }
-
   return raw;
 }

compiler/apps/playground/next-env.d.ts

@@ -1,6 +1,5 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
-/// <reference path="./.next/types/routes.d.ts" />
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/app/api-reference/config/typescript for more information.

compiler/apps/playground/package.json

@@ -34,30 +34,26 @@
     "invariant": "^2.2.4",
     "lz-string": "^1.5.0",
     "monaco-editor": "^0.52.0",
-    "next": "15.5.2",
+    "next": "^15.2.0-canary.64",
     "notistack": "^3.0.0-alpha.7",
     "prettier": "^3.3.3",
     "pretty-format": "^29.3.1",
     "re-resizable": "^6.9.16",
-    "react": "19.1.1",
-    "react-dom": "19.1.1"
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0"
   },
   "devDependencies": {
     "@types/node": "18.11.9",
-    "@types/react": "19.1.12",
-    "@types/react-dom": "19.1.9",
+    "@types/react": "^19.0.0",
+    "@types/react-dom": "^19.0.0",
     "autoprefixer": "^10.4.13",
     "clsx": "^1.2.1",
     "concurrently": "^7.4.0",
     "eslint": "^8.28.0",
-    "eslint-config-next": "15.5.2",
+    "eslint-config-next": "^15.0.1",
     "monaco-editor-webpack-plugin": "^7.1.0",
     "postcss": "^8.4.31",
     "tailwindcss": "^3.2.4",
     "wait-on": "^7.2.0"
-  },
-  "resolutions": {
-    "@types/react": "19.1.12",
-    "@types/react-dom": "19.1.9"
   }
 }

compiler/packages/babel-plugin-react-compiler/src/CompilerError.ts

@@ -36,14 +36,6 @@ export enum ErrorSeverity {
    * memoization.
    */
   CannotPreserveMemoization = 'CannotPreserveMemoization',
-  /**
-   * An API that is known to be incompatible with the compiler. Generally as a result of
-   * the library using "interior mutability", ie having a value whose referential identity
-   * stays the same but which provides access to values that can change. For example a
-   * function that doesn't change but returns different results, or an object that doesn't
-   * change identity but whose properties change.
-   */
-  IncompatibleLibrary = 'IncompatibleLibrary',
   /**
    * Unhandled syntax that we don't support yet.
    */
@@ -466,8 +458,7 @@ export class CompilerError extends Error {
         case ErrorSeverity.InvalidJS:
         case ErrorSeverity.InvalidReact:
         case ErrorSeverity.InvalidConfig:
-        case ErrorSeverity.UnsupportedJS:
-        case ErrorSeverity.IncompatibleLibrary: {
+        case ErrorSeverity.UnsupportedJS: {
           return true;
         }
         case ErrorSeverity.CannotPreserveMemoization:
@@ -515,9 +506,8 @@ function printErrorSummary(severity: ErrorSeverity, message: string): string {
       severityCategory = 'Error';
       break;
     }
-    case ErrorSeverity.IncompatibleLibrary:
     case ErrorSeverity.CannotPreserveMemoization: {
-      severityCategory = 'Compilation Skipped';
+      severityCategory = 'Memoization';
       break;
     }
     case ErrorSeverity.Invariant: {
@@ -557,9 +547,6 @@ export enum ErrorCategory {
   // Checks that manual memoization is preserved
   PreserveManualMemo = 'PreserveManualMemo',
 
-  // Checks for known incompatible libraries
-  IncompatibleLibrary = 'IncompatibleLibrary',
-
   // Checking for no mutations of props, hook arguments, hook return values
   Immutability = 'Immutability',
 
@@ -883,15 +870,6 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
         recommended: true,
       };
     }
-    case ErrorCategory.IncompatibleLibrary: {
-      return {
-        category,
-        name: 'incompatible-library',
-        description:
-          'Validates against usage of libraries which are incompatible with memoization (manual or automatic)',
-        recommended: true,
-      };
-    }
     default: {
       assertExhaustive(category, `Unsupported category ${category}`);
     }

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Options.ts

@@ -135,7 +135,12 @@ export type PluginOptions = {
    */
   eslintSuppressionRules: Array<string> | null | undefined;
 
+  /**
+   * Whether to report "suppression" errors for Flow suppressions. If false, suppression errors
+   * are only emitted for ESLint suppressions
+   */
   flowSuppressions: boolean;
+
   /*
    * Ignore 'use no forget' annotations. Helpful during testing but should not be used in production.
    */

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Suppression.ts

@@ -87,12 +87,18 @@ export function findProgramSuppressions(
   let enableComment: t.Comment | null = null;
   let source: SuppressionSource | null = null;
 
-  const rulePattern = `(${ruleNames.join('|')})`;
-  const disableNextLinePattern = new RegExp(
-    `eslint-disable-next-line ${rulePattern}`,
-  );
-  const disablePattern = new RegExp(`eslint-disable ${rulePattern}`);
-  const enablePattern = new RegExp(`eslint-enable ${rulePattern}`);
+  let disableNextLinePattern: RegExp | null = null;
+  let disablePattern: RegExp | null = null;
+  let enablePattern: RegExp | null = null;
+  if (ruleNames.length !== 0) {
+    const rulePattern = `(${ruleNames.join('|')})`;
+    disableNextLinePattern = new RegExp(
+      `eslint-disable-next-line ${rulePattern}`,
+    );
+    disablePattern = new RegExp(`eslint-disable ${rulePattern}`);
+    enablePattern = new RegExp(`eslint-enable ${rulePattern}`);
+  }
+
   const flowSuppressionPattern = new RegExp(
     '\\$(FlowFixMe\\w*|FlowExpectedError|FlowIssue)\\[react\\-rule',
   );
@@ -108,6 +114,7 @@ export function findProgramSuppressions(
        * CommentLine within the block.
        */
       disableComment == null &&
+      disableNextLinePattern != null &&
       disableNextLinePattern.test(comment.value)
     ) {
       disableComment = comment;
@@ -125,12 +132,16 @@ export function findProgramSuppressions(
       source = 'Flow';
     }
 
-    if (disablePattern.test(comment.value)) {
+    if (disablePattern != null && disablePattern.test(comment.value)) {
       disableComment = comment;
       source = 'Eslint';
     }
 
-    if (enablePattern.test(comment.value) && source === 'Eslint') {
+    if (
+      enablePattern != null &&
+      enablePattern.test(comment.value) &&
+      source === 'Eslint'
+    ) {
       enableComment = comment;
     }
 

compiler/packages/babel-plugin-react-compiler/src/HIR/DefaultModuleTypeProvider.ts

@@ -1,91 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import {Effect, ValueKind} from '..';
-import {TypeConfig} from './TypeSchema';
-
-/**
- * Libraries developed before we officially documented the [Rules of React](https://react.dev/reference/rules)
- * implement APIs which cannot be memoized safely, either via manual or automatic memoization.
- *
- * Any non-hook API that is designed to be called during render (not events/effects) should be safe to memoize:
- *
- * ```js
- * function Component() {
- *   const {someFunction} = useLibrary();
- *   // it should always be safe to memoize functions like this
- *  const result = useMemo(() => someFunction(), [someFunction]);
- * }
- * ```
- *
- * However, some APIs implement "interior mutability" — mutating values rather than copying into a new value
- * and setting state with the new value. Such functions (`someFunction()` in the example) could return different
- * values even though the function itself is the same object. This breaks memoization, since React relies on
- * the outer object (or function) changing if part of its value has changed.
- *
- * Given that we didn't have the Rules of React precisely documented prior to the introduction of React compiler,
- * it's understandable that some libraries accidentally shipped APIs that break this rule. However, developers
- * can easily run into pitfalls with these APIs. They may manually memoize them, which can break their app. Or
- * they may try using React Compiler, and think that the compiler has broken their code.
- *
- * To help ensure that developers can successfully use the compiler with existing code, this file teaches the
- * compiler about specific APIs that are known to be incompatible with memoization. We've tried to be as precise
- * as possible.
- *
- * The React team is open to collaborating with library authors to help develop compatible versions of these APIs,
- * and we have already reached out to the teams who own any API listed here to ensure they are aware of the issue.
- */
-export function defaultModuleTypeProvider(
-  moduleName: string,
-): TypeConfig | null {
-  switch (moduleName) {
-    case 'react-hook-form': {
-      return {
-        kind: 'object',
-        properties: {
-          useForm: {
-            kind: 'hook',
-            returnType: {
-              kind: 'object',
-              properties: {
-                // Only the `watch()` function returned by react-hook-form's `useForm()` API is incompatible
-                watch: {
-                  kind: 'function',
-                  positionalParams: [],
-                  restParam: Effect.Read,
-                  calleeEffect: Effect.Read,
-                  returnType: {kind: 'type', name: 'Any'},
-                  returnValueKind: ValueKind.Mutable,
-                  knownIncompatible: `React Hook Form's \`useForm()\` API returns a \`watch()\` function which cannot be memoized safely.`,
-                },
-              },
-            },
-          },
-        },
-      };
-    }
-    case '@tanstack/react-table': {
-      return {
-        kind: 'object',
-        properties: {
-          /*
-           * Many of the properties of `useReactTable()`'s return value are incompatible, so we mark the entire hook
-           * as incompatible
-           */
-          useReactTable: {
-            kind: 'hook',
-            positionalParams: [],
-            restParam: Effect.Read,
-            returnType: {kind: 'type', name: 'Any'},
-            knownIncompatible: `TanStack Table's \`useReactTable()\` API returns functions that cannot be memoized safely`,
-          },
-        },
-      };
-    }
-  }
-  return null;
-}

compiler/packages/babel-plugin-react-compiler/src/HIR/Environment.ts

@@ -50,7 +50,6 @@ import {
 import {Scope as BabelScope, NodePath} from '@babel/traverse';
 import {TypeSchema} from './TypeSchema';
 import {FlowTypeEnv} from '../Flood/Types';
-import {defaultModuleTypeProvider} from './DefaultModuleTypeProvider';
 
 export const ReactElementSymbolSchema = z.object({
   elementSymbol: z.union([
@@ -861,16 +860,10 @@ export class Environment {
   #resolveModuleType(moduleName: string, loc: SourceLocation): Global | null {
     let moduleType = this.#moduleTypes.get(moduleName);
     if (moduleType === undefined) {
-      /*
-       * NOTE: Zod doesn't work when specifying a function as a default, so we have to
-       * fallback to the default value here
-       */
-      const moduleTypeProvider =
-        this.config.moduleTypeProvider ?? defaultModuleTypeProvider;
-      if (moduleTypeProvider == null) {
+      if (this.config.moduleTypeProvider == null) {
         return null;
       }
-      const unparsedModuleConfig = moduleTypeProvider(moduleName);
+      const unparsedModuleConfig = this.config.moduleTypeProvider(moduleName);
       if (unparsedModuleConfig != null) {
         const parsedModuleConfig = TypeSchema.safeParse(unparsedModuleConfig);
         if (!parsedModuleConfig.success) {

compiler/packages/babel-plugin-react-compiler/src/HIR/Globals.ts

@@ -1001,7 +1001,6 @@ export function installTypeConfig(
         mutableOnlyIfOperandsAreMutable:
           typeConfig.mutableOnlyIfOperandsAreMutable === true,
         aliasing: typeConfig.aliasing,
-        knownIncompatible: typeConfig.knownIncompatible ?? null,
       });
     }
     case 'hook': {
@@ -1020,7 +1019,6 @@ export function installTypeConfig(
         returnValueKind: typeConfig.returnValueKind ?? ValueKind.Frozen,
         noAlias: typeConfig.noAlias === true,
         aliasing: typeConfig.aliasing,
-        knownIncompatible: typeConfig.knownIncompatible ?? null,
       });
     }
     case 'object': {

compiler/packages/babel-plugin-react-compiler/src/HIR/ObjectShape.ts

@@ -332,7 +332,6 @@ export type FunctionSignature = {
   mutableOnlyIfOperandsAreMutable?: boolean;
 
   impure?: boolean;
-  knownIncompatible?: string | null | undefined;
 
   canonicalName?: string;
 

compiler/packages/babel-plugin-react-compiler/src/HIR/TypeSchema.ts

@@ -251,7 +251,6 @@ export type FunctionTypeConfig = {
   impure?: boolean | null | undefined;
   canonicalName?: string | null | undefined;
   aliasing?: AliasingSignatureConfig | null | undefined;
-  knownIncompatible?: string | null | undefined;
 };
 export const FunctionTypeSchema: z.ZodType<FunctionTypeConfig> = z.object({
   kind: z.literal('function'),
@@ -265,7 +264,6 @@ export const FunctionTypeSchema: z.ZodType<FunctionTypeConfig> = z.object({
   impure: z.boolean().nullable().optional(),
   canonicalName: z.string().nullable().optional(),
   aliasing: AliasingSignatureSchema.nullable().optional(),
-  knownIncompatible: z.string().nullable().optional(),
 });
 
 export type HookTypeConfig = {
@@ -276,7 +274,6 @@ export type HookTypeConfig = {
   returnValueKind?: ValueKind | null | undefined;
   noAlias?: boolean | null | undefined;
   aliasing?: AliasingSignatureConfig | null | undefined;
-  knownIncompatible?: string | null | undefined;
 };
 export const HookTypeSchema: z.ZodType<HookTypeConfig> = z.object({
   kind: z.literal('hook'),
@@ -286,7 +283,6 @@ export const HookTypeSchema: z.ZodType<HookTypeConfig> = z.object({
   returnValueKind: ValueKindSchema.nullable().optional(),
   noAlias: z.boolean().nullable().optional(),
   aliasing: AliasingSignatureSchema.nullable().optional(),
-  knownIncompatible: z.string().nullable().optional(),
 });
 
 export type BuiltInTypeConfig =

compiler/packages/babel-plugin-react-compiler/src/Inference/InferMutationAliasingEffects.ts

@@ -2089,7 +2089,7 @@ function computeSignatureForInstruction(
           effects.push({
             kind: 'Freeze',
             value: operand,
-            reason: ValueReason.HookCaptured,
+            reason: ValueReason.Other,
           });
         }
       }
@@ -2170,27 +2170,6 @@ function computeEffectsForLegacySignature(
       }),
     });
   }
-  if (signature.knownIncompatible != null && state.env.isInferredMemoEnabled) {
-    const errors = new CompilerError();
-    errors.pushDiagnostic(
-      CompilerDiagnostic.create({
-        category: ErrorCategory.IncompatibleLibrary,
-        severity: ErrorSeverity.IncompatibleLibrary,
-        reason: 'Use of incompatible library',
-        description: [
-          'This API returns functions which cannot be memoized without leading to stale UI. ' +
-            'To prevent this, by default React Compiler will skip memoizing this component/hook. ' +
-            'However, you may see issues if values from this API are passed to other components/hooks that are ' +
-            'memoized.',
-        ].join(''),
-      }).withDetail({
-        kind: 'error',
-        loc: receiver.loc,
-        message: signature.knownIncompatible,
-      }),
-    );
-    throw errors;
-  }
   const stores: Array<Place> = [];
   const captures: Array<Place> = [];
   function visit(place: Place, effect: Effect): void {

compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/AlignReactiveScopesToBlockScopesHIR.ts

@@ -175,41 +175,6 @@ export function alignReactiveScopesToBlockScopesHIR(fn: HIRFunction): void {
       if (node != null) {
         valueBlockNodes.set(fallthrough, node);
       }
-    } else if (terminal.kind === 'goto') {
-      /**
-       * If we encounter a goto that is not to the natural fallthrough of the current
-       * block (not the topmost fallthrough on the stack), then this is a goto to a
-       * label. Any scopes that extend beyond the goto must be extended to include
-       * the labeled range, so that the break statement doesn't accidentally jump
-       * out of the scope. We do this by extending the start and end of the scope's
-       * range to the label and its fallthrough respectively.
-       */
-      const start = activeBlockFallthroughRanges.find(
-        range => range.fallthrough === terminal.block,
-      );
-      if (start != null && start !== activeBlockFallthroughRanges.at(-1)) {
-        const fallthroughBlock = fn.body.blocks.get(start.fallthrough)!;
-        const firstId =
-          fallthroughBlock.instructions[0]?.id ?? fallthroughBlock.terminal.id;
-        for (const scope of activeScopes) {
-          /**
-           * activeScopes is only filtered at block start points, so some of the
-           * scopes may not actually be active anymore, ie we've past their end
-           * instruction. Only extend ranges for scopes that are actually active.
-           *
-           * TODO: consider pruning activeScopes per instruction
-           */
-          if (scope.range.end <= terminal.id) {
-            continue;
-          }
-          scope.range.start = makeInstructionId(
-            Math.min(start.range.start, scope.range.start),
-          );
-          scope.range.end = makeInstructionId(
-            Math.max(firstId, scope.range.end),
-          );
-        }
-      }
     }
 
     /*

compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/PruneNonEscapingScopes.ts

@@ -411,9 +411,7 @@ class CollectDependenciesVisitor extends ReactiveFunctionVisitor<
     this.state = state;
     this.options = {
       memoizeJsxElements: !this.env.config.enableForest,
-      forceMemoizePrimitives:
-        this.env.config.enableForest ||
-        this.env.config.enablePreserveExistingMemoizationGuarantees,
+      forceMemoizePrimitives: this.env.config.enableForest,
     };
   }
 
@@ -536,23 +534,9 @@ class CollectDependenciesVisitor extends ReactiveFunctionVisitor<
       case 'JSXText':
       case 'BinaryExpression':
       case 'UnaryExpression': {
-        if (options.forceMemoizePrimitives) {
-          /**
-           * Because these instructions produce primitives we usually don't consider
-           * them as escape points: they are known to copy, not return references.
-           * However if we're forcing memoization of primitives then we mark these
-           * instructions as needing memoization and walk their rvalues to ensure
-           * any scopes transitively reachable from the rvalues are considered for
-           * memoization. Note: we may still prune primitive-producing scopes if
-           * they don't ultimately escape at all.
-           */
-          const level = MemoizationLevel.Conditional;
-          return {
-            lvalues: lvalue !== null ? [{place: lvalue, level}] : [],
-            rvalues: [...eachReactiveValueOperand(value)],
-          };
-        }
-        const level = MemoizationLevel.Never;
+        const level = options.forceMemoizePrimitives
+          ? MemoizationLevel.Memoized
+          : MemoizationLevel.Never;
         return {
           // All of these instructions return a primitive value and never need to be memoized
           lvalues: lvalue !== null ? [{place: lvalue, level}] : [],
@@ -701,7 +685,9 @@ class CollectDependenciesVisitor extends ReactiveFunctionVisitor<
       }
       case 'ComputedLoad':
       case 'PropertyLoad': {
-        const level = MemoizationLevel.Conditional;
+        const level = options.forceMemoizePrimitives
+          ? MemoizationLevel.Memoized
+          : MemoizationLevel.Conditional;
         return {
           // Indirection for the inner value, memoized if the value is
           lvalues: lvalue !== null ? [{place: lvalue, level}] : [],

compiler/packages/babel-plugin-react-compiler/src/Utils/TestUtils.ts

@@ -255,16 +255,11 @@ function parseConfigStringAsJS(
 
   console.log('OVERRIDE:', parsedConfig);
 
-  const environment = parseConfigPragmaEnvironmentForTest(
-    '',
-    defaults.environment ?? {},
-  );
-
   const options: Record<keyof PluginOptions, unknown> = {
     ...defaultOptions,
     panicThreshold: 'all_errors',
     compilationMode: defaults.compilationMode,
-    environment,
+    environment: defaults.environment ?? defaultOptions.environment,
   };
 
   // Apply parsed config, merging environment if it exists
@@ -274,9 +269,22 @@ function parseConfigStringAsJS(
       ...parsedConfig.environment,
     };
 
+    // Apply complex defaults for environment flags that are set to true
+    const environmentConfig: Partial<Record<keyof EnvironmentConfig, unknown>> =
+      {};
+    for (const [key, value] of Object.entries(mergedEnvironment)) {
+      if (hasOwnProperty(EnvironmentConfigSchema.shape, key)) {
+        if (value === true && key in testComplexConfigDefaults) {
+          environmentConfig[key] = testComplexConfigDefaults[key];
+        } else {
+          environmentConfig[key] = value;
+        }
+      }
+    }
+
     // Validate environment config
     const validatedEnvironment =
-      EnvironmentConfigSchema.safeParse(mergedEnvironment);
+      EnvironmentConfigSchema.safeParse(environmentConfig);
     if (!validatedEnvironment.success) {
       CompilerError.invariant(false, {
         reason: 'Invalid environment configuration in config pragma',
@@ -286,6 +294,10 @@ function parseConfigStringAsJS(
       });
     }
 
+    if (validatedEnvironment.data.enableResetCacheOnSourceFileChanges == null) {
+      validatedEnvironment.data.enableResetCacheOnSourceFileChanges = false;
+    }
+
     options.environment = validatedEnvironment.data;
   }
 
@@ -296,7 +308,9 @@ function parseConfigStringAsJS(
     }
 
     if (hasOwnProperty(defaultOptions, key)) {
-      if (key === 'target' && value === 'donotuse_meta_internal') {
+      if (value === true && key in testComplexPluginOptionDefaults) {
+        options[key] = testComplexPluginOptionDefaults[key];
+      } else if (key === 'target' && value === 'donotuse_meta_internal') {
         options[key] = {
           kind: value,
           runtimeModule: 'react',

compiler/packages/babel-plugin-react-compiler/src/Validation/ValidatePreservedManualMemoization.ts

@@ -284,7 +284,8 @@ function validateInferredDep(
     CompilerDiagnostic.create({
       category: ErrorCategory.PreserveManualMemo,
       severity: ErrorSeverity.CannotPreserveMemoization,
-      reason: 'Existing memoization could not be preserved',
+      reason:
+        'Compilation skipped because existing memoization could not be preserved',
       description: [
         'React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. ',
         'The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. ',
@@ -538,7 +539,8 @@ class Visitor extends ReactiveFunctionVisitor<VisitorState> {
             CompilerDiagnostic.create({
               category: ErrorCategory.PreserveManualMemo,
               severity: ErrorSeverity.CannotPreserveMemoization,
-              reason: 'Existing memoization could not be preserved',
+              reason:
+                'Compilation skipped because existing memoization could not be preserved',
               description: [
                 'React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. ',
                 'This dependency may be mutated later, which could cause the value to change unexpectedly.',
@@ -586,7 +588,8 @@ class Visitor extends ReactiveFunctionVisitor<VisitorState> {
                 CompilerDiagnostic.create({
                   category: ErrorCategory.PreserveManualMemo,
                   severity: ErrorSeverity.CannotPreserveMemoization,
-                  reason: 'Existing memoization could not be preserved',
+                  reason:
+                    'Compilation skipped because existing memoization could not be preserved',
                   description: [
                     'React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This value was memoized in source but not in compilation output. ',
                     DEBUG

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/align-scopes-reactive-scope-overlaps-if.expect.md

@@ -46,16 +46,14 @@ function useFoo(t0) {
     t1 = $[0];
   }
   let items = t1;
-  if ($[1] !== cond) {
-    bb0: {
-      if (cond) {
-        items = [];
-      } else {
-        break bb0;
-      }
-
-      items.push(2);
+  bb0: if ($[1] !== cond) {
+    if (cond) {
+      items = [];
+    } else {
+      break bb0;
     }
+
+    items.push(2);
     $[1] = cond;
     $[2] = items;
   } else {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/dont-memoize-primitive-function-call-non-escaping-useMemo.expect.md

@@ -1,77 +0,0 @@
-
-## Input
-
-```javascript
-// @compilationMode:"infer" @enablePreserveExistingMemoizationGuarantees @validatePreserveExistingMemoizationGuarantees
-import {useMemo} from 'react';
-import {makeObject_Primitives, ValidateMemoization} from 'shared-runtime';
-
-function Component(props) {
-  const result = useMemo(
-    () => makeObject(props.value).value + 1,
-    [props.value]
-  );
-  console.log(result);
-  return 'ok';
-}
-
-function makeObject(value) {
-  console.log(value);
-  return {value};
-}
-
-export const TODO_FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-  sequentialRenders: [
-    {value: 42},
-    {value: 42},
-    {value: 3.14},
-    {value: 3.14},
-    {value: 42},
-    {value: 3.14},
-    {value: 42},
-    {value: 3.14},
-  ],
-};
-
-```
-
-## Code
-
-```javascript
-// @compilationMode:"infer" @enablePreserveExistingMemoizationGuarantees @validatePreserveExistingMemoizationGuarantees
-import { useMemo } from "react";
-import { makeObject_Primitives, ValidateMemoization } from "shared-runtime";
-
-function Component(props) {
-  const result = makeObject(props.value).value + 1;
-
-  console.log(result);
-  return "ok";
-}
-
-function makeObject(value) {
-  console.log(value);
-  return { value };
-}
-
-export const TODO_FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{ value: 42 }],
-  sequentialRenders: [
-    { value: 42 },
-    { value: 42 },
-    { value: 3.14 },
-    { value: 3.14 },
-    { value: 42 },
-    { value: 3.14 },
-    { value: 42 },
-    { value: 3.14 },
-  ],
-};
-
-```
-      
-### Eval output
-(kind: exception) Fixture not implemented

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/dont-memoize-primitive-function-call-non-escaping-useMemo.js

@@ -1,32 +0,0 @@
-// @compilationMode:"infer" @enablePreserveExistingMemoizationGuarantees @validatePreserveExistingMemoizationGuarantees
-import {useMemo} from 'react';
-import {makeObject_Primitives, ValidateMemoization} from 'shared-runtime';
-
-function Component(props) {
-  const result = useMemo(
-    () => makeObject(props.value).value + 1,
-    [props.value]
-  );
-  console.log(result);
-  return 'ok';
-}
-
-function makeObject(value) {
-  console.log(value);
-  return {value};
-}
-
-export const TODO_FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-  sequentialRenders: [
-    {value: 42},
-    {value: 42},
-    {value: 3.14},
-    {value: 3.14},
-    {value: 42},
-    {value: 3.14},
-    {value: 42},
-    {value: 3.14},
-  ],
-};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/dont-memoize-primitive-function-call-non-escaping.expect.md

@@ -1,81 +0,0 @@
-
-## Input
-
-```javascript
-// @compilationMode:"infer" @enablePreserveExistingMemoizationGuarantees @validatePreserveExistingMemoizationGuarantees
-import {useMemo} from 'react';
-import {makeObject_Primitives, ValidateMemoization} from 'shared-runtime';
-
-function Component(props) {
-  const result = makeObject(props.value).value + 1;
-  console.log(result);
-  return 'ok';
-}
-
-function makeObject(value) {
-  console.log(value);
-  return {value};
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-  sequentialRenders: [
-    {value: 42},
-    {value: 42},
-    {value: 3.14},
-    {value: 3.14},
-    {value: 42},
-    {value: 3.14},
-    {value: 42},
-    {value: 3.14},
-  ],
-};
-
-```
-
-## Code
-
-```javascript
-// @compilationMode:"infer" @enablePreserveExistingMemoizationGuarantees @validatePreserveExistingMemoizationGuarantees
-import { useMemo } from "react";
-import { makeObject_Primitives, ValidateMemoization } from "shared-runtime";
-
-function Component(props) {
-  const result = makeObject(props.value).value + 1;
-  console.log(result);
-  return "ok";
-}
-
-function makeObject(value) {
-  console.log(value);
-  return { value };
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{ value: 42 }],
-  sequentialRenders: [
-    { value: 42 },
-    { value: 42 },
-    { value: 3.14 },
-    { value: 3.14 },
-    { value: 42 },
-    { value: 3.14 },
-    { value: 42 },
-    { value: 3.14 },
-  ],
-};
-
-```
-      
-### Eval output
-(kind: ok) "ok"
-"ok"
-"ok"
-"ok"
-"ok"
-"ok"
-"ok"
-"ok"
-logs: [42,43,42,43,3.14,4.140000000000001,3.14,4.140000000000001,42,43,3.14,4.140000000000001,42,43,3.14,4.140000000000001]

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/dont-memoize-primitive-function-call-non-escaping.js

@@ -1,29 +0,0 @@
-// @compilationMode:"infer" @enablePreserveExistingMemoizationGuarantees @validatePreserveExistingMemoizationGuarantees
-import {useMemo} from 'react';
-import {makeObject_Primitives, ValidateMemoization} from 'shared-runtime';
-
-function Component(props) {
-  const result = makeObject(props.value).value + 1;
-  console.log(result);
-  return 'ok';
-}
-
-function makeObject(value) {
-  console.log(value);
-  return {value};
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-  sequentialRenders: [
-    {value: 42},
-    {value: 42},
-    {value: 3.14},
-    {value: 3.14},
-    {value: 42},
-    {value: 3.14},
-    {value: 42},
-    {value: 3.14},
-  ],
-};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/empty-eslint-suppressions-config.expect.md

@@ -0,0 +1,53 @@
+
+## Input
+
+```javascript
+// @eslintSuppressionRules:[]
+
+// The suppression here shouldn't cause compilation to get skipped
+// Previously we had a bug where an empty list of suppressions would
+// create a regexp that matched any suppression
+function Component(props) {
+  'use forget';
+  // eslint-disable-next-line foo/not-react-related
+  return <div>{props.text}</div>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{text: 'Hello'}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime"; // @eslintSuppressionRules:[]
+
+// The suppression here shouldn't cause compilation to get skipped
+// Previously we had a bug where an empty list of suppressions would
+// create a regexp that matched any suppression
+function Component(props) {
+  "use forget";
+  const $ = _c(2);
+  let t0;
+  if ($[0] !== props.text) {
+    t0 = <div>{props.text}</div>;
+    $[0] = props.text;
+    $[1] = t0;
+  } else {
+    t0 = $[1];
+  }
+  return t0;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ text: "Hello" }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>Hello</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/empty-eslint-suppressions-config.js

@@ -0,0 +1,15 @@
+// @eslintSuppressionRules:[]
+
+// The suppression here shouldn't cause compilation to get skipped
+// Previously we had a bug where an empty list of suppressions would
+// create a regexp that matched any suppression
+function Component(props) {
+  'use forget';
+  // eslint-disable-next-line foo/not-react-related
+  return <div>{props.text}</div>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{text: 'Hello'}],
+};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.hoist-optional-member-expression-with-conditional-optional.expect.md

@@ -26,7 +26,7 @@ function Component(props) {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `props.items`, but the source dependencies were [props?.items, props.cond]. Inferred different dependency than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.hoist-optional-member-expression-with-conditional.expect.md

@@ -26,7 +26,7 @@ function Component(props) {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `props.items`, but the source dependencies were [props?.items, props.cond]. Inferred different dependency than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-known-incompatible-function.expect.md

@@ -1,34 +0,0 @@
-
-## Input
-
-```javascript
-import {knownIncompatible} from 'ReactCompilerKnownIncompatibleTest';
-
-function Component() {
-  const data = knownIncompatible();
-  return <div>Error</div>;
-}
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Compilation Skipped: Use of incompatible library
-
-This API returns functions which cannot be memoized without leading to stale UI. To prevent this, by default React Compiler will skip memoizing this component/hook. However, you may see issues if values from this API are passed to other components/hooks that are memoized.
-
-error.invalid-known-incompatible-function.ts:4:15
-  2 |
-  3 | function Component() {
-> 4 |   const data = knownIncompatible();
-    |                ^^^^^^^^^^^^^^^^^ useKnownIncompatible is known to be incompatible
-  5 |   return <div>Error</div>;
-  6 | }
-  7 |
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-known-incompatible-function.js

@@ -1,6 +0,0 @@
-import {knownIncompatible} from 'ReactCompilerKnownIncompatibleTest';
-
-function Component() {
-  const data = knownIncompatible();
-  return <div>Error</div>;
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-known-incompatible-hook-return-property.expect.md

@@ -1,33 +0,0 @@
-
-## Input
-
-```javascript
-import {useKnownIncompatibleIndirect} from 'ReactCompilerKnownIncompatibleTest';
-
-function Component() {
-  const {incompatible} = useKnownIncompatibleIndirect();
-  return <div>{incompatible()}</div>;
-}
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Compilation Skipped: Use of incompatible library
-
-This API returns functions which cannot be memoized without leading to stale UI. To prevent this, by default React Compiler will skip memoizing this component/hook. However, you may see issues if values from this API are passed to other components/hooks that are memoized.
-
-error.invalid-known-incompatible-hook-return-property.ts:5:15
-  3 | function Component() {
-  4 |   const {incompatible} = useKnownIncompatibleIndirect();
-> 5 |   return <div>{incompatible()}</div>;
-    |                ^^^^^^^^^^^^ useKnownIncompatibleIndirect returns an incompatible() function that is known incompatible
-  6 | }
-  7 |
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-known-incompatible-hook-return-property.js

@@ -1,6 +0,0 @@
-import {useKnownIncompatibleIndirect} from 'ReactCompilerKnownIncompatibleTest';
-
-function Component() {
-  const {incompatible} = useKnownIncompatibleIndirect();
-  return <div>{incompatible()}</div>;
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-known-incompatible-hook.expect.md

@@ -1,34 +0,0 @@
-
-## Input
-
-```javascript
-import {useKnownIncompatible} from 'ReactCompilerKnownIncompatibleTest';
-
-function Component() {
-  const data = useKnownIncompatible();
-  return <div>Error</div>;
-}
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Compilation Skipped: Use of incompatible library
-
-This API returns functions which cannot be memoized without leading to stale UI. To prevent this, by default React Compiler will skip memoizing this component/hook. However, you may see issues if values from this API are passed to other components/hooks that are memoized.
-
-error.invalid-known-incompatible-hook.ts:4:15
-  2 |
-  3 | function Component() {
-> 4 |   const data = useKnownIncompatible();
-    |                ^^^^^^^^^^^^^^^^^^^^ useKnownIncompatible is known to be incompatible
-  5 |   return <div>Error</div>;
-  6 | }
-  7 |
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-known-incompatible-hook.js

@@ -1,6 +0,0 @@
-import {useKnownIncompatible} from 'ReactCompilerKnownIncompatibleTest';
-
-function Component() {
-  const data = useKnownIncompatible();
-  return <div>Error</div>;
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-optional-member-expression-as-memo-dep-non-optional-in-body.expect.md

@@ -20,7 +20,7 @@ function Component(props) {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `props.items.edges.nodes`, but the source dependencies were [props.items?.edges?.nodes]. Inferred different dependency than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-useEffect-dep-not-memoized-bc-range-overlaps-hook.expect.md

@@ -25,7 +25,7 @@ function Component(props) {
 ```
 Found 1 error:
 
-Compilation Skipped: React Compiler has skipped optimizing this component because the effect dependencies could not be memoized. Unmemoized effect dependencies can trigger an infinite loop or other unexpected behavior
+Memoization: React Compiler has skipped optimizing this component because the effect dependencies could not be memoized. Unmemoized effect dependencies can trigger an infinite loop or other unexpected behavior
 
 error.invalid-useEffect-dep-not-memoized-bc-range-overlaps-hook.ts:9:2
    7 |

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-useEffect-dep-not-memoized.expect.md

@@ -22,7 +22,7 @@ function Component(props) {
 ```
 Found 1 error:
 
-Compilation Skipped: React Compiler has skipped optimizing this component because the effect dependencies could not be memoized. Unmemoized effect dependencies can trigger an infinite loop or other unexpected behavior
+Memoization: React Compiler has skipped optimizing this component because the effect dependencies could not be memoized. Unmemoized effect dependencies can trigger an infinite loop or other unexpected behavior
 
 error.invalid-useEffect-dep-not-memoized.ts:6:2
    4 | function Component(props) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-useInsertionEffect-dep-not-memoized.expect.md

@@ -22,7 +22,7 @@ function Component(props) {
 ```
 Found 1 error:
 
-Compilation Skipped: React Compiler has skipped optimizing this component because the effect dependencies could not be memoized. Unmemoized effect dependencies can trigger an infinite loop or other unexpected behavior
+Memoization: React Compiler has skipped optimizing this component because the effect dependencies could not be memoized. Unmemoized effect dependencies can trigger an infinite loop or other unexpected behavior
 
 error.invalid-useInsertionEffect-dep-not-memoized.ts:6:2
    4 | function Component(props) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-useLayoutEffect-dep-not-memoized.expect.md

@@ -22,7 +22,7 @@ function Component(props) {
 ```
 Found 1 error:
 
-Compilation Skipped: React Compiler has skipped optimizing this component because the effect dependencies could not be memoized. Unmemoized effect dependencies can trigger an infinite loop or other unexpected behavior
+Memoization: React Compiler has skipped optimizing this component because the effect dependencies could not be memoized. Unmemoized effect dependencies can trigger an infinite loop or other unexpected behavior
 
 error.invalid-useLayoutEffect-dep-not-memoized.ts:6:2
    4 | function Component(props) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.ref-like-name-not-Ref.expect.md

@@ -33,7 +33,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `Ref.current`, but the source dependencies were []. Inferred dependency not present in source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.ref-like-name-not-a-ref.expect.md

@@ -33,7 +33,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `notaref.current`, but the source dependencies were []. Inferred dependency not present in source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-repro-missed-memoization-from-capture-in-invoked-function-inferred-as-mutation.expect.md

@@ -44,7 +44,7 @@ component Component() {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This value was memoized in source but not in compilation output.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-repro-missed-memoization-from-inferred-mutation-in-logger.expect.md

@@ -54,7 +54,7 @@ component Component(id) {
 ```
 Found 3 errors:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This value was memoized in source but not in compilation output.
 
@@ -76,7 +76,7 @@ React Compiler has skipped optimizing this component because the existing manual
   18 |   const setCurrentIndex = useCallback(
   19 |     (index: number) => {
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This dependency may be mutated later, which could cause the value to change unexpectedly.
 
@@ -88,7 +88,7 @@ React Compiler has skipped optimizing this component because the existing manual
   30 |
   31 |   if (prevId !== id) {
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This value was memoized in source but not in compilation output.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-repro-unmemoized-callback-captured-in-context-variable.expect.md

@@ -52,7 +52,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This value was memoized in source but not in compilation output.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.validate-memoized-effect-deps-invalidated-dep-value.expect.md

@@ -30,7 +30,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 1 error:
 
-Compilation Skipped: React Compiler has skipped optimizing this component because the effect dependencies could not be memoized. Unmemoized effect dependencies can trigger an infinite loop or other unexpected behavior
+Memoization: React Compiler has skipped optimizing this component because the effect dependencies could not be memoized. Unmemoized effect dependencies can trigger an infinite loop or other unexpected behavior
 
 error.validate-memoized-effect-deps-invalidated-dep-value.ts:11:2
    9 |   const y = [x];

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.validate-object-entries-mutation.expect.md

@@ -27,7 +27,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 2 errors:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This dependency may be mutated later, which could cause the value to change unexpectedly.
 
@@ -40,7 +40,7 @@ error.validate-object-entries-mutation.ts:6:57
   8 |     value.updated = true;
   9 |   });
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This value was memoized in source but not in compilation output.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.validate-object-values-mutation.expect.md

@@ -27,7 +27,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 2 errors:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This dependency may be mutated later, which could cause the value to change unexpectedly.
 
@@ -40,7 +40,7 @@ error.validate-object-values-mutation.ts:6:55
   8 |     value.updated = true;
   9 |   });
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This value was memoized in source but not in compilation output.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/gating/dynamic-gating-bailout-nopanic.expect.md

@@ -58,7 +58,7 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileError","fnLoc":{"start":{"line":6,"column":0,"index":206},"end":{"line":16,"column":1,"index":433},"filename":"dynamic-gating-bailout-nopanic.ts"},"detail":{"options":{"category":"PreserveManualMemo","severity":"CannotPreserveMemoization","reason":"Existing memoization could not be preserved","description":"React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `value`, but the source dependencies were []. Inferred dependency not present in source.","suggestions":null,"details":[{"kind":"error","loc":{"start":{"line":9,"column":31,"index":288},"end":{"line":9,"column":52,"index":309},"filename":"dynamic-gating-bailout-nopanic.ts"},"message":"Could not preserve existing manual memoization"}]}}}
+{"kind":"CompileError","fnLoc":{"start":{"line":6,"column":0,"index":206},"end":{"line":16,"column":1,"index":433},"filename":"dynamic-gating-bailout-nopanic.ts"},"detail":{"options":{"category":"PreserveManualMemo","severity":"CannotPreserveMemoization","reason":"Compilation skipped because existing memoization could not be preserved","description":"React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `value`, but the source dependencies were []. Inferred dependency not present in source.","suggestions":null,"details":[{"kind":"error","loc":{"start":{"line":9,"column":31,"index":288},"end":{"line":9,"column":52,"index":309},"filename":"dynamic-gating-bailout-nopanic.ts"},"message":"Could not preserve existing manual memoization"}]}}}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/memoize-primitive-function-calls.expect.md

@@ -1,107 +0,0 @@
-
-## Input
-
-```javascript
-// @compilationMode:"infer" @enablePreserveExistingMemoizationGuarantees @validatePreserveExistingMemoizationGuarantees
-import {useMemo} from 'react';
-import {makeObject_Primitives, ValidateMemoization} from 'shared-runtime';
-
-function Component(props) {
-  const result = useMemo(() => {
-    return makeObject(props.value).value + 1;
-  }, [props.value]);
-  return <ValidateMemoization inputs={[props.value]} output={result} />;
-}
-
-function makeObject(value) {
-  console.log(value);
-  return {value};
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-  sequentialRenders: [
-    {value: 42},
-    {value: 42},
-    {value: 3.14},
-    {value: 3.14},
-    {value: 42},
-    {value: 3.14},
-    {value: 42},
-    {value: 3.14},
-  ],
-};
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime"; // @compilationMode:"infer" @enablePreserveExistingMemoizationGuarantees @validatePreserveExistingMemoizationGuarantees
-import { useMemo } from "react";
-import { makeObject_Primitives, ValidateMemoization } from "shared-runtime";
-
-function Component(props) {
-  const $ = _c(7);
-  let t0;
-  if ($[0] !== props.value) {
-    t0 = makeObject(props.value);
-    $[0] = props.value;
-    $[1] = t0;
-  } else {
-    t0 = $[1];
-  }
-  const result = t0.value + 1;
-  let t1;
-  if ($[2] !== props.value) {
-    t1 = [props.value];
-    $[2] = props.value;
-    $[3] = t1;
-  } else {
-    t1 = $[3];
-  }
-  let t2;
-  if ($[4] !== result || $[5] !== t1) {
-    t2 = <ValidateMemoization inputs={t1} output={result} />;
-    $[4] = result;
-    $[5] = t1;
-    $[6] = t2;
-  } else {
-    t2 = $[6];
-  }
-  return t2;
-}
-
-function makeObject(value) {
-  console.log(value);
-  return { value };
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{ value: 42 }],
-  sequentialRenders: [
-    { value: 42 },
-    { value: 42 },
-    { value: 3.14 },
-    { value: 3.14 },
-    { value: 42 },
-    { value: 3.14 },
-    { value: 42 },
-    { value: 3.14 },
-  ],
-};
-
-```
-      
-### Eval output
-(kind: ok) <div>{"inputs":[42],"output":43}</div>
-<div>{"inputs":[42],"output":43}</div>
-<div>{"inputs":[3.14],"output":4.140000000000001}</div>
-<div>{"inputs":[3.14],"output":4.140000000000001}</div>
-<div>{"inputs":[42],"output":43}</div>
-<div>{"inputs":[3.14],"output":4.140000000000001}</div>
-<div>{"inputs":[42],"output":43}</div>
-<div>{"inputs":[3.14],"output":4.140000000000001}</div>
-logs: [42,3.14,42,3.14,42,3.14]

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/memoize-primitive-function-calls.js

@@ -1,30 +0,0 @@
-// @compilationMode:"infer" @enablePreserveExistingMemoizationGuarantees @validatePreserveExistingMemoizationGuarantees
-import {useMemo} from 'react';
-import {makeObject_Primitives, ValidateMemoization} from 'shared-runtime';
-
-function Component(props) {
-  const result = useMemo(() => {
-    return makeObject(props.value).value + 1;
-  }, [props.value]);
-  return <ValidateMemoization inputs={[props.value]} output={result} />;
-}
-
-function makeObject(value) {
-  console.log(value);
-  return {value};
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-  sequentialRenders: [
-    {value: 42},
-    {value: 42},
-    {value: 3.14},
-    {value: 3.14},
-    {value: 42},
-    {value: 3.14},
-    {value: 42},
-    {value: 3.14},
-  ],
-};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/meta-isms/repro-cx-namespace-nesting.expect.md

@@ -2,7 +2,6 @@
 ## Input
 
 ```javascript
-// @compilationMode:"infer"
 import {makeArray} from 'shared-runtime';
 
 function Component() {
@@ -31,7 +30,7 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-import { c as _c } from "react/compiler-runtime"; // @compilationMode:"infer"
+import { c as _c } from "react/compiler-runtime";
 import { makeArray } from "shared-runtime";
 
 function Component() {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/meta-isms/repro-cx-namespace-nesting.js

@@ -1,4 +1,3 @@
-// @compilationMode:"infer"
 import {makeArray} from 'shared-runtime';
 
 function Component() {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/mutation-within-jsx-and-break.expect.md

@@ -49,12 +49,12 @@ import {
 } from "shared-runtime";
 
 function useFoo(t0) {
-  const $ = _c(4);
+  const $ = _c(3);
   const { data } = t0;
   let obj;
   let myDiv = null;
-  if ($[0] !== data.cond || $[1] !== data.cond1) {
-    bb0: if (data.cond) {
+  bb0: if (data.cond) {
+    if ($[0] !== data.cond1) {
       obj = makeObject_Primitives();
       if (data.cond1) {
         myDiv = <Stringify value={mutateAndReturn(obj)} />;
@@ -62,14 +62,13 @@ function useFoo(t0) {
       }
 
       mutate(obj);
+      $[0] = data.cond1;
+      $[1] = obj;
+      $[2] = myDiv;
+    } else {
+      obj = $[1];
+      myDiv = $[2];
     }
-    $[0] = data.cond;
-    $[1] = data.cond1;
-    $[2] = obj;
-    $[3] = myDiv;
-  } else {
-    obj = $[2];
-    myDiv = $[3];
   }
   return myDiv;
 }

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/new-mutability/error.invalid-useCallback-captures-reassigned-context.expect.md

@@ -31,7 +31,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 2 errors:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This dependency may be mutated later, which could cause the value to change unexpectedly.
 
@@ -44,7 +44,7 @@ error.invalid-useCallback-captures-reassigned-context.ts:11:37
   13 |   x = makeArray();
   14 |
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This value was memoized in source but not in compilation output.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-existing-memoization-guarantees/lambda-with-fbt-preserve-memoization.expect.md

@@ -1,86 +0,0 @@
-
-## Input
-
-```javascript
-// @enablePreserveExistingMemoizationGuarantees
-import {fbt} from 'fbt';
-
-function Component() {
-  const buttonLabel = () => {
-    if (!someCondition) {
-      return <fbt desc="My label">{'Purchase as a gift'}</fbt>;
-    } else if (
-      !iconOnly &&
-      showPrice &&
-      item?.current_gift_offer?.price?.formatted != null
-    ) {
-      return (
-        <fbt desc="Gift button's label">
-          {'Gift | '}
-          <fbt:param name="price">
-            {item?.current_gift_offer?.price?.formatted}
-          </fbt:param>
-        </fbt>
-      );
-    } else if (!iconOnly && !showPrice) {
-      return <fbt desc="Gift button's label">{'Gift'}</fbt>;
-    }
-  };
-
-  return (
-    <View>
-      <Button text={buttonLabel()} />
-    </View>
-  );
-}
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime"; // @enablePreserveExistingMemoizationGuarantees
-import { fbt } from "fbt";
-
-function Component() {
-  const $ = _c(1);
-  const buttonLabel = _temp;
-  let t0;
-  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-    t0 = (
-      <View>
-        <Button text={buttonLabel()} />
-      </View>
-    );
-    $[0] = t0;
-  } else {
-    t0 = $[0];
-  }
-  return t0;
-}
-function _temp() {
-  if (!someCondition) {
-    return fbt._("Purchase as a gift", null, { hk: "1gHj4g" });
-  } else {
-    if (
-      !iconOnly &&
-      showPrice &&
-      item?.current_gift_offer?.price?.formatted != null
-    ) {
-      return fbt._(
-        "Gift | {price}",
-        [fbt._param("price", item?.current_gift_offer?.price?.formatted)],
-        { hk: "3GTnGE" },
-      );
-    } else {
-      if (!iconOnly && !showPrice) {
-        return fbt._("Gift", null, { hk: "3fqfrk" });
-      }
-    }
-  }
-}
-
-```
-      
-### Eval output
-(kind: exception) Fixture not implemented

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-existing-memoization-guarantees/lambda-with-fbt-preserve-memoization.js

@@ -1,31 +0,0 @@
-// @enablePreserveExistingMemoizationGuarantees
-import {fbt} from 'fbt';
-
-function Component() {
-  const buttonLabel = () => {
-    if (!someCondition) {
-      return <fbt desc="My label">{'Purchase as a gift'}</fbt>;
-    } else if (
-      !iconOnly &&
-      showPrice &&
-      item?.current_gift_offer?.price?.formatted != null
-    ) {
-      return (
-        <fbt desc="Gift button's label">
-          {'Gift | '}
-          <fbt:param name="price">
-            {item?.current_gift_offer?.price?.formatted}
-          </fbt:param>
-        </fbt>
-      );
-    } else if (!iconOnly && !showPrice) {
-      return <fbt desc="Gift button's label">{'Gift'}</fbt>;
-    }
-  };
-
-  return (
-    <View>
-      <Button text={buttonLabel()} />
-    </View>
-  );
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.false-positive-useMemo-dropped-infer-always-invalidating.expect.md

@@ -32,7 +32,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This value was memoized in source but not in compilation output.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.false-positive-useMemo-infer-mutate-deps.expect.md

@@ -31,7 +31,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This dependency may be mutated later, which could cause the value to change unexpectedly.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.false-positive-useMemo-overlap-scopes.expect.md

@@ -42,7 +42,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This dependency may be mutated later, which could cause the value to change unexpectedly.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.hoist-useCallback-conditional-access-own-scope.expect.md

@@ -28,7 +28,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `propB`, but the source dependencies were [propA, propB.x.y]. Inferred less specific property than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.hoist-useCallback-infer-conditional-value-block.expect.md

@@ -31,7 +31,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 2 errors:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `propA`, but the source dependencies were [propA.a, propB.x.y]. Inferred less specific property than source.
 
@@ -60,7 +60,7 @@ error.hoist-useCallback-infer-conditional-value-block.ts:6:21
   16 |
   17 | export const FIXTURE_ENTRYPOINT = {
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `propB`, but the source dependencies were [propA.a, propB.x.y]. Inferred less specific property than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.invalid-useCallback-captures-reassigned-context.expect.md

@@ -32,7 +32,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 2 errors:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This dependency may be mutated later, which could cause the value to change unexpectedly.
 
@@ -45,7 +45,7 @@ error.invalid-useCallback-captures-reassigned-context.ts:12:37
   14 |   x = makeArray();
   15 |
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This value was memoized in source but not in compilation output.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.preserve-use-memo-ref-missing-reactive.expect.md

@@ -30,7 +30,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `ref`, but the source dependencies were []. Inferred dependency not present in source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.todo-useCallback-captures-invalidating-value.expect.md

@@ -30,7 +30,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. This value was memoized in source but not in compilation output.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useCallback-aliased-var.expect.md

@@ -21,7 +21,7 @@ function useHook(x) {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `aliasedX`, but the source dependencies were [x, aliasedProp]. Inferred different dependency than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useCallback-conditional-access-noAlloc.expect.md

@@ -27,7 +27,7 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `propB?.x.y`, but the source dependencies were [propA, propB.x.y]. Inferred different dependency than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useCallback-infer-less-specific-conditional-access.expect.md

@@ -26,7 +26,7 @@ function Component({propA, propB}) {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `propB`, but the source dependencies were [propA?.a, propB.x.y]. Inferred less specific property than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useCallback-property-call-dep.expect.md

@@ -19,7 +19,7 @@ function Component({propA}) {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `propA`, but the source dependencies were [propA.x]. Inferred less specific property than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useMemo-aliased-var.expect.md

@@ -21,7 +21,7 @@ function useHook(x) {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `x`, but the source dependencies were [aliasedX, aliasedProp]. Inferred different dependency than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useMemo-infer-less-specific-conditional-access.expect.md

@@ -26,7 +26,7 @@ function Component({propA, propB}) {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `propB`, but the source dependencies were [propA?.a, propB.x.y]. Inferred less specific property than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useMemo-infer-less-specific-conditional-value-block.expect.md

@@ -26,7 +26,7 @@ function Component({propA, propB}) {
 ```
 Found 2 errors:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `propA`, but the source dependencies were [propA.a, propB.x.y]. Inferred less specific property than source.
 
@@ -54,7 +54,7 @@ error.useMemo-infer-less-specific-conditional-value-block.ts:6:17
   15 | }
   16 |
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `propB`, but the source dependencies were [propA.a, propB.x.y]. Inferred less specific property than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useMemo-property-call-chained-object.expect.md

@@ -21,7 +21,7 @@ function Component({propA}) {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `propA`, but the source dependencies were [propA.x]. Inferred less specific property than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useMemo-property-call-dep.expect.md

@@ -19,7 +19,7 @@ function Component({propA}) {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `propA`, but the source dependencies were [propA.x]. Inferred less specific property than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useMemo-unrelated-mutation-in-depslist.expect.md

@@ -32,7 +32,7 @@ function useFoo(input1) {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `input1`, but the source dependencies were [y]. Inferred different dependency than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/primitive-reassigned-loop-force-scopes-enabled.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @enablePreserveExistingMemoizationGuarantees
+// @enableForest
 function Component({base, start, increment, test}) {
   let value = base;
   for (let i = start; i < test; i += increment) {
@@ -27,23 +27,25 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-import { c as _c } from "react/compiler-runtime"; // @enablePreserveExistingMemoizationGuarantees
+import { c as _c } from "react/compiler-runtime"; // @enableForest
 function Component(t0) {
-  const $ = _c(2);
+  const $ = _c(5);
   const { base, start, increment, test } = t0;
-  let value = base;
-  for (let i = start; i < test; i = i + increment, i) {
-    value = value + i;
-  }
-  let t1;
-  if ($[0] !== value) {
-    t1 = <div>{value}</div>;
-    $[0] = value;
-    $[1] = t1;
+  let value;
+  if ($[0] !== base || $[1] !== increment || $[2] !== start || $[3] !== test) {
+    value = base;
+    for (let i = start; i < test; i = i + increment, i) {
+      value = value + i;
+    }
+    $[0] = base;
+    $[1] = increment;
+    $[2] = start;
+    $[3] = test;
+    $[4] = value;
   } else {
-    t1 = $[1];
+    value = $[4];
   }
-  return t1;
+  return <div>{value}</div>;
 }
 
 export const FIXTURE_ENTRYPOINT = {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/primitive-reassigned-loop-force-scopes-enabled.js

@@ -1,4 +1,4 @@
-// @enablePreserveExistingMemoizationGuarantees
+// @enableForest
 function Component({base, start, increment, test}) {
   let value = base;
   for (let i = start; i < test; i += increment) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/propagate-scope-deps-hir-fork/error.todo-optional-member-expression-with-conditional-optional.expect.md

@@ -26,7 +26,7 @@ function Component(props) {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `props.items`, but the source dependencies were [props?.items, props.cond]. Inferred different dependency than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/propagate-scope-deps-hir-fork/error.todo-optional-member-expression-with-conditional.expect.md

@@ -26,7 +26,7 @@ function Component(props) {
 ```
 Found 1 error:
 
-Compilation Skipped: Existing memoization could not be preserved
+Memoization: Compilation skipped because existing memoization could not be preserved
 
 React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `props.items`, but the source dependencies were [props?.items, props.cond]. Inferred different dependency than source.
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/propagate-scope-deps-hir-fork/useMemo-multiple-if-else.expect.md

@@ -34,16 +34,17 @@ import { c as _c } from "react/compiler-runtime"; // @enablePropagateDepsInHIR
 import { useMemo } from "react";
 
 function Component(props) {
-  const $ = _c(5);
+  const $ = _c(6);
   let t0;
-  if (
-    $[0] !== props.a ||
-    $[1] !== props.b ||
-    $[2] !== props.cond ||
-    $[3] !== props.cond2
-  ) {
-    bb0: {
-      const y = [];
+  bb0: {
+    let y;
+    if (
+      $[0] !== props.a ||
+      $[1] !== props.b ||
+      $[2] !== props.cond ||
+      $[3] !== props.cond2
+    ) {
+      y = [];
       if (props.cond) {
         y.push(props.a);
       }
@@ -53,15 +54,17 @@ function Component(props) {
       }
 
       y.push(props.b);
-      t0 = y;
+      $[0] = props.a;
+      $[1] = props.b;
+      $[2] = props.cond;
+      $[3] = props.cond2;
+      $[4] = y;
+      $[5] = t0;
+    } else {
+      y = $[4];
+      t0 = $[5];
     }
-    $[0] = props.a;
-    $[1] = props.b;
-    $[2] = props.cond;
-    $[3] = props.cond2;
-    $[4] = t0;
-  } else {
-    t0 = $[4];
+    t0 = y;
   }
   const x = t0;
   return x;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/repro-useMemo-if-else-both-early-return.expect.md

@@ -1,118 +0,0 @@
-
-## Input
-
-```javascript
-import {useMemo} from 'react';
-import {
-  makeObject_Primitives,
-  mutate,
-  Stringify,
-  ValidateMemoization,
-} from 'shared-runtime';
-
-function Component({cond}) {
-  const memoized = useMemo(() => {
-    const value = makeObject_Primitives();
-    if (cond) {
-      return value;
-    } else {
-      mutate(value);
-      return value;
-    }
-  }, [cond]);
-  return <ValidateMemoization inputs={[cond]} output={memoized} />;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{cond: false}],
-  sequentialRenders: [
-    {cond: false},
-    {cond: false},
-    {cond: true},
-    {cond: true},
-    {cond: false},
-    {cond: true},
-    {cond: false},
-    {cond: true},
-  ],
-};
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime";
-import { useMemo } from "react";
-import {
-  makeObject_Primitives,
-  mutate,
-  Stringify,
-  ValidateMemoization,
-} from "shared-runtime";
-
-function Component(t0) {
-  const $ = _c(7);
-  const { cond } = t0;
-  let t1;
-  if ($[0] !== cond) {
-    const value = makeObject_Primitives();
-    if (cond) {
-      t1 = value;
-    } else {
-      mutate(value);
-      t1 = value;
-    }
-    $[0] = cond;
-    $[1] = t1;
-  } else {
-    t1 = $[1];
-  }
-  const memoized = t1;
-  let t2;
-  if ($[2] !== cond) {
-    t2 = [cond];
-    $[2] = cond;
-    $[3] = t2;
-  } else {
-    t2 = $[3];
-  }
-  let t3;
-  if ($[4] !== memoized || $[5] !== t2) {
-    t3 = <ValidateMemoization inputs={t2} output={memoized} />;
-    $[4] = memoized;
-    $[5] = t2;
-    $[6] = t3;
-  } else {
-    t3 = $[6];
-  }
-  return t3;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{ cond: false }],
-  sequentialRenders: [
-    { cond: false },
-    { cond: false },
-    { cond: true },
-    { cond: true },
-    { cond: false },
-    { cond: true },
-    { cond: false },
-    { cond: true },
-  ],
-};
-
-```
-      
-### Eval output
-(kind: ok) <div>{"inputs":[false],"output":{"a":0,"b":"value1","c":true,"wat0":"joe"}}</div>
-<div>{"inputs":[false],"output":{"a":0,"b":"value1","c":true,"wat0":"joe"}}</div>
-<div>{"inputs":[true],"output":{"a":0,"b":"value1","c":true}}</div>
-<div>{"inputs":[true],"output":{"a":0,"b":"value1","c":true}}</div>
-<div>{"inputs":[false],"output":{"a":0,"b":"value1","c":true,"wat0":"joe"}}</div>
-<div>{"inputs":[true],"output":{"a":0,"b":"value1","c":true}}</div>
-<div>{"inputs":[false],"output":{"a":0,"b":"value1","c":true,"wat0":"joe"}}</div>
-<div>{"inputs":[true],"output":{"a":0,"b":"value1","c":true}}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/repro-useMemo-if-else-both-early-return.js

@@ -1,35 +0,0 @@
-import {useMemo} from 'react';
-import {
-  makeObject_Primitives,
-  mutate,
-  Stringify,
-  ValidateMemoization,
-} from 'shared-runtime';
-
-function Component({cond}) {
-  const memoized = useMemo(() => {
-    const value = makeObject_Primitives();
-    if (cond) {
-      return value;
-    } else {
-      mutate(value);
-      return value;
-    }
-  }, [cond]);
-  return <ValidateMemoization inputs={[cond]} output={memoized} />;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{cond: false}],
-  sequentialRenders: [
-    {cond: false},
-    {cond: false},
-    {cond: true},
-    {cond: true},
-    {cond: false},
-    {cond: true},
-    {cond: false},
-    {cond: true},
-  ],
-};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/useMemo-multiple-if-else.expect.md

@@ -33,16 +33,17 @@ import { c as _c } from "react/compiler-runtime";
 import { useMemo } from "react";
 
 function Component(props) {
-  const $ = _c(5);
+  const $ = _c(6);
   let t0;
-  if (
-    $[0] !== props.a ||
-    $[1] !== props.b ||
-    $[2] !== props.cond ||
-    $[3] !== props.cond2
-  ) {
-    bb0: {
-      const y = [];
+  bb0: {
+    let y;
+    if (
+      $[0] !== props.a ||
+      $[1] !== props.b ||
+      $[2] !== props.cond ||
+      $[3] !== props.cond2
+    ) {
+      y = [];
       if (props.cond) {
         y.push(props.a);
       }
@@ -52,15 +53,17 @@ function Component(props) {
       }
 
       y.push(props.b);
-      t0 = y;
+      $[0] = props.a;
+      $[1] = props.b;
+      $[2] = props.cond;
+      $[3] = props.cond2;
+      $[4] = y;
+      $[5] = t0;
+    } else {
+      y = $[4];
+      t0 = $[5];
     }
-    $[0] = props.a;
-    $[1] = props.b;
-    $[2] = props.cond;
-    $[3] = props.cond2;
-    $[4] = t0;
-  } else {
-    t0 = $[4];
+    t0 = y;
   }
   const x = t0;
   return x;

compiler/packages/babel-plugin-react-compiler/src/index.ts

@@ -48,7 +48,10 @@ export {
   printReactiveFunction,
   printReactiveFunctionWithOutlined,
 } from './ReactiveScopes';
-export {parseConfigPragmaForTests} from './Utils/TestUtils';
+export {
+  parseConfigPragmaForTests,
+  parseConfigPragmaAsString,
+} from './Utils/TestUtils';
 declare global {
   let __DEV__: boolean | null | undefined;
 }

compiler/packages/snap/src/sprout/shared-runtime-type-provider.ts

@@ -198,51 +198,6 @@ export function makeSharedRuntimeTypeProvider({
           },
         },
       };
-    } else if (moduleName === 'ReactCompilerKnownIncompatibleTest') {
-      /**
-       * Fake module used for testing validation of known incompatible
-       * API validation
-       */
-      return {
-        kind: 'object',
-        properties: {
-          useKnownIncompatible: {
-            kind: 'hook',
-            positionalParams: [],
-            restParam: EffectEnum.Read,
-            returnType: {kind: 'type', name: 'Any'},
-            knownIncompatible: `useKnownIncompatible is known to be incompatible`,
-          },
-          useKnownIncompatibleIndirect: {
-            kind: 'hook',
-            positionalParams: [],
-            restParam: EffectEnum.Read,
-            returnType: {
-              kind: 'object',
-              properties: {
-                incompatible: {
-                  kind: 'function',
-                  positionalParams: [],
-                  restParam: EffectEnum.Read,
-                  calleeEffect: EffectEnum.Read,
-                  returnType: {kind: 'type', name: 'Any'},
-                  returnValueKind: ValueKindEnum.Mutable,
-                  knownIncompatible: `useKnownIncompatibleIndirect returns an incompatible() function that is known incompatible`,
-                },
-              },
-            },
-          },
-          knownIncompatible: {
-            kind: 'function',
-            positionalParams: [],
-            restParam: EffectEnum.Read,
-            calleeEffect: EffectEnum.Read,
-            returnType: {kind: 'type', name: 'Any'},
-            returnValueKind: ValueKindEnum.Mutable,
-            knownIncompatible: `useKnownIncompatible is known to be incompatible`,
-          },
-        },
-      };
     } else if (moduleName === 'ReactCompilerTest') {
       /**
        * Fake module used for testing validation that type providers return hook

fixtures/flight/server/region.js

@@ -74,7 +74,13 @@ function getDebugChannel(req) {
   return activeDebugChannels.get(requestId);
 }
 
-async function renderApp(res, returnValue, formState, noCache, debugChannel) {
+async function renderApp(
+  res,
+  returnValue,
+  formState,
+  noCache,
+  promiseForDebugChannel
+) {
   const {renderToPipeableStream} = await import(
     'react-server-dom-webpack/server'
   );
@@ -126,7 +132,7 @@ async function renderApp(res, returnValue, formState, noCache, debugChannel) {
   // For client-invoked server actions we refresh the tree and return a return value.
   const payload = {root, returnValue, formState};
   const {pipe} = renderToPipeableStream(payload, moduleMap, {
-    debugChannel,
+    debugChannel: await promiseForDebugChannel,
     filterStackFrame,
   });
   pipe(res);
@@ -379,20 +385,23 @@ app.on('error', function (error) {
 if (process.env.NODE_ENV === 'development') {
   // Open a websocket server for Debug information
   const WebSocket = require('ws');
+  const webSocketServer = new WebSocket.Server({noServer: true});
 
-  const webSocketServer = new WebSocket.Server({
-    server: httpServer,
-    path: '/debug-channel',
-  });
-
-  webSocketServer.on('connection', (ws, req) => {
-    const url = new URL(req.url, `http://${req.headers.host}`);
-    const requestId = url.searchParams.get('id');
-
-    activeDebugChannels.set(requestId, ws);
-
-    ws.on('close', (code, reason) => {
-      activeDebugChannels.delete(requestId);
-    });
+  httpServer.on('upgrade', (request, socket, head) => {
+    const DEBUG_CHANNEL_PATH = '/debug-channel?';
+    if (request.url.startsWith(DEBUG_CHANNEL_PATH)) {
+      const requestId = request.url.slice(DEBUG_CHANNEL_PATH.length);
+      const promiseForWs = new Promise(resolve => {
+        webSocketServer.handleUpgrade(request, socket, head, ws => {
+          ws.on('close', () => {
+            activeDebugChannels.delete(requestId);
+          });
+          resolve(ws);
+        });
+      });
+      activeDebugChannels.set(requestId, promiseForWs);
+    } else {
+      socket.destroy();
+    }
   });
 }

fixtures/flight/src/index.js

@@ -14,52 +14,18 @@ function findSourceMapURL(fileName) {
   );
 }
 
-async function createWebSocketStream(url) {
-  const ws = new WebSocket(url);
-  ws.binaryType = 'arraybuffer';
-
-  await new Promise((resolve, reject) => {
-    ws.addEventListener('open', resolve, {once: true});
-    ws.addEventListener('error', reject, {once: true});
-  });
-
-  const writable = new WritableStream({
-    write(chunk) {
-      ws.send(chunk);
-    },
-    close() {
-      ws.close();
-    },
-    abort(reason) {
-      ws.close(1000, reason && String(reason));
-    },
-  });
-
-  const readable = new ReadableStream({
-    start(controller) {
-      ws.addEventListener('message', event => {
-        controller.enqueue(event.data);
-      });
-      ws.addEventListener('close', () => {
-        controller.close();
-      });
-      ws.addEventListener('error', err => {
-        controller.error(err);
-      });
-    },
-  });
-
-  return {readable, writable};
-}
-
 let updateRoot;
 async function callServer(id, args) {
   let response;
-  if (process.env.NODE_ENV === 'development') {
+  if (
+    process.env.NODE_ENV === 'development' &&
+    typeof WebSocketStream === 'function'
+  ) {
     const requestId = crypto.randomUUID();
-    const debugChannel = await createWebSocketStream(
-      `ws://localhost:3001/debug-channel?id=${requestId}`
+    const wss = new WebSocketStream(
+      'ws://localhost:3001/debug-channel?' + requestId
     );
+    const debugChannel = await wss.opened;
     response = createFromFetch(
       fetch('/', {
         method: 'POST',
@@ -108,11 +74,15 @@ function Shell({data}) {
 
 async function hydrateApp() {
   let response;
-  if (process.env.NODE_ENV === 'development') {
+  if (
+    process.env.NODE_ENV === 'development' &&
+    typeof WebSocketStream === 'function'
+  ) {
     const requestId = crypto.randomUUID();
-    const debugChannel = await createWebSocketStream(
-      `ws://localhost:3001/debug-channel?id=${requestId}`
+    const wss = new WebSocketStream(
+      'ws://localhost:3001/debug-channel?' + requestId
     );
+    const debugChannel = await wss.opened;
     response = createFromFetch(
       fetch('/', {
         headers: {

packages/eslint-plugin-react-hooks/README.md

@@ -22,22 +22,15 @@ yarn add eslint-plugin-react-hooks --dev
 
 #### >= 6.0.0
 
-For users of 6.0 and beyond, add the `recommended` config.
+For users of 6.0 and beyond, simply add the `recommended` config.
 
 ```js
-// eslint.config.js
-import reactHooks from 'eslint-plugin-react-hooks';
-import { defineConfig } from 'eslint/config';
+import * as reactHooks from 'eslint-plugin-react-hooks';
 
-export default defineConfig([
-  {
-    files: ["src/**/*.{js,jsx,ts,tsx}"],
-    plugins: {
-      'react-hooks': reactHooks,
-    },
-    extends: ['react-hooks/recommended'],
-  },
-]);
+export default [
+  // ...
+  reactHooks.configs.recommended,
+];
 ```
 
 #### 5.2.0
@@ -45,18 +38,12 @@ export default defineConfig([
 For users of 5.2.0 (the first version with flat config support), add the `recommended-latest` config.
 
 ```js
-import reactHooks from 'eslint-plugin-react-hooks';
-import { defineConfig } from 'eslint/config';
+import * as reactHooks from 'eslint-plugin-react-hooks';
 
-export default defineConfig([
-  {
-    files: ["src/**/*.{js,jsx,ts,tsx}"],
-    plugins: {
-      'react-hooks': reactHooks,
-    },
-    extends: ['react-hooks/recommended-latest'],
-  },
-]);
+export default [
+  // ...
+  reactHooks.configs['recommended-latest'],
+];
 ```
 
 ### Legacy Config (.eslintrc)

packages/react-client/src/ReactFlightClient.js

@@ -1010,15 +1010,10 @@ export function reportGlobalError(
   if (__DEV__) {
     const debugChannel = response._debugChannel;
     if (debugChannel !== undefined) {
-      // If we don't have any more ways of reading data, we don't have to send
-      // any more neither. So we close the writable side.
+      // If we don't have any more ways of reading data, we don't have to send any
+      // more neither. So we close the writable side.
       closeDebugChannel(debugChannel);
       response._debugChannel = undefined;
-      // Make sure the debug channel is not closed a second time when the
-      // Response gets GC:ed.
-      if (debugChannelRegistry !== null) {
-        debugChannelRegistry.unregister(response);
-      }
     }
   }
 }
@@ -1074,14 +1069,7 @@ function getTaskName(type: mixed): string {
   }
 }
 
-function initializeElement(
-  response: Response,
-  element: any,
-  lazyType: null | LazyComponent<
-    React$Element<any>,
-    SomeChunk<React$Element<any>>,
-  >,
-): void {
+function initializeElement(response: Response, element: any): void {
   if (!__DEV__) {
     return;
   }
@@ -1148,18 +1136,6 @@ function initializeElement(
   if (owner !== null) {
     initializeFakeStack(response, owner);
   }
-
-  // In case the JSX runtime has validated the lazy type as a static child, we
-  // need to transfer this information to the element.
-  if (
-    lazyType &&
-    lazyType._store &&
-    lazyType._store.validated &&
-    !element._store.validated
-  ) {
-    element._store.validated = lazyType._store.validated;
-  }
-
   // TODO: We should be freezing the element but currently, we might write into
   // _debugInfo later. We could move it into _store which remains mutable.
   Object.freeze(element.props);
@@ -1172,7 +1148,7 @@ function createElement(
   props: mixed,
   owner: ?ReactComponentInfo, // DEV-only
   stack: ?ReactStackTrace, // DEV-only
-  validated: 0 | 1 | 2, // DEV-only
+  validated: number, // DEV-only
 ):
   | React$Element<any>
   | LazyComponent<React$Element<any>, SomeChunk<React$Element<any>>> {
@@ -1249,7 +1225,7 @@ function createElement(
         handler.reason,
       );
       if (__DEV__) {
-        initializeElement(response, element, null);
+        initializeElement(response, element);
         // Conceptually the error happened inside this Element but right before
         // it was rendered. We don't have a client side component to render but
         // we can add some DebugInfo to explain that this was conceptually a
@@ -1268,7 +1244,7 @@ function createElement(
         }
         erroredChunk._debugInfo = [erroredComponent];
       }
-      return createLazyChunkWrapper(erroredChunk, validated);
+      return createLazyChunkWrapper(erroredChunk);
     }
     if (handler.deps > 0) {
       // We have blocked references inside this Element but we can turn this into
@@ -1277,17 +1253,16 @@ function createElement(
         createBlockedChunk(response);
       handler.value = element;
       handler.chunk = blockedChunk;
-      const lazyType = createLazyChunkWrapper(blockedChunk, validated);
       if (__DEV__) {
-        // After we have initialized any blocked references, initialize stack etc.
-        const init = initializeElement.bind(null, response, element, lazyType);
+        /// After we have initialized any blocked references, initialize stack etc.
+        const init = initializeElement.bind(null, response, element);
         blockedChunk.then(init, init);
       }
-      return lazyType;
+      return createLazyChunkWrapper(blockedChunk);
     }
   }
   if (__DEV__) {
-    initializeElement(response, element, null);
+    initializeElement(response, element);
   }
 
   return element;
@@ -1295,7 +1270,6 @@ function createElement(
 
 function createLazyChunkWrapper<T>(
   chunk: SomeChunk<T>,
-  validated: 0 | 1 | 2, // DEV-only
 ): LazyComponent<T, SomeChunk<T>> {
   const lazyType: LazyComponent<T, SomeChunk<T>> = {
     $$typeof: REACT_LAZY_TYPE,
@@ -1307,8 +1281,6 @@ function createLazyChunkWrapper<T>(
     const chunkDebugInfo: ReactDebugInfo =
       chunk._debugInfo || (chunk._debugInfo = ([]: ReactDebugInfo));
     lazyType._debugInfo = chunkDebugInfo;
-    // Initialize a store for key validation by the JSX runtime.
-    lazyType._store = {validated: validated};
   }
   return lazyType;
 }
@@ -2113,7 +2085,7 @@ function parseModelString(
         }
         // We create a React.lazy wrapper around any lazy values.
         // When passed into React, we'll know how to suspend on this.
-        return createLazyChunkWrapper(chunk, 0);
+        return createLazyChunkWrapper(chunk);
       }
       case '@': {
         // Promise
@@ -2462,7 +2434,7 @@ function ResponseInstance(
         // When a Response gets GC:ed because nobody is referring to any of the
         // objects that lazily load from the Response anymore, then we can close
         // the debug channel.
-        debugChannelRegistry.register(this, debugChannel, this);
+        debugChannelRegistry.register(this, debugChannel);
       }
     }
   }

packages/react-devtools-shared/src/devtools/views/Components/Element.js

@@ -80,8 +80,8 @@ export default function Element({data, index, style}: Props): React.Node {
   };
 
   // $FlowFixMe[missing-local-annot]
-  const handleClick = ({metaKey, button}) => {
-    if (id !== null && button === 0) {
+  const handleClick = ({metaKey}) => {
+    if (id !== null) {
       logEvent({
         event_name: 'select-element',
         metadata: {source: 'click-element'},

packages/react-devtools-shared/src/devtools/views/SuspenseTab/SuspenseTab.css

@@ -16,15 +16,14 @@
 
 .TreeWrapper {
   border-top: 1px solid var(--color-border);
-  flex: 1 1 65%;
+  flex: 1 1 var(--horizontal-resize-tree-percentage);
   display: flex;
   flex-direction: row;
   height: 100%;
-  overflow: auto;
 }
 
 .InspectedElementWrapper {
-  flex: 0 0 calc(100% - var(--horizontal-resize-tree-percentage));
+  flex: 1 1 35%;
   overflow-x: hidden;
   overflow-y: auto;
 }
@@ -60,12 +59,12 @@
 
   .TreeWrapper {
     border-top: 1px solid var(--color-border);
-    flex: 1 1 50%;
+    flex: 1 1 var(--vertical-resize-tree-percentage);
     overflow: hidden;
   }
 
   .InspectedElementWrapper {
-    flex: 0 0 calc(100% - var(--vertical-resize-tree-percentage));
+    flex: 1 1 50%;
   }
 
   .TreeWrapper + .ResizeBarWrapper .ResizeBar {

packages/react-devtools-shared/src/devtools/views/SuspenseTab/SuspenseTimeline.css

@@ -2,18 +2,13 @@
   width: 100%;
   display: flex;
   flex-direction: row;
-  padding: 0.25rem;
+  padding: 0 0.25rem;
 }
 
 .SuspenseTimelineInput {
   display: flex;
   flex-direction: column;
   flex-grow: 1;
-  /* 
-   * `overflow: auto` will add scrollbars but the input will not actually grow beyond visible content.
-   * `overflow: hidden` will constrain the input to its visible content.
-   */
-  overflow: hidden;
 }
 
 .SuspenseTimelineRootSwitcher {
@@ -21,6 +16,20 @@
   max-width: 3rem;
 }
 
-.SuspenseTimelineProgressIndicator {
-  align-self: center;
+.SuspenseTimelineMarkers {
+  display: flex;
+  flex-direction: row;
+  justify-content: space-between;
 }
+
+.SuspenseTimelineMarkers > * {
+  flex: 1 1 0;
+  overflow: visible;
+  visibility: hidden;
+  width: 0
+}
+
+.SuspenseTimelineActiveMarker {
+  visibility: visible;
+}
+

packages/react-devtools-shared/src/devtools/views/SuspenseTab/SuspenseTimeline.js

@@ -11,7 +11,14 @@ import type {Element, SuspenseNode} from '../../../frontend/types';
 import type Store from '../../store';
 
 import * as React from 'react';
-import {useContext, useLayoutEffect, useMemo, useRef, useState} from 'react';
+import {
+  useContext,
+  useId,
+  useLayoutEffect,
+  useMemo,
+  useRef,
+  useState,
+} from 'react';
 import {BridgeContext, StoreContext} from '../context';
 import {TreeDispatcherContext} from '../Components/TreeContext';
 import {useHighlightHostInstance} from '../hooks';
@@ -105,6 +112,30 @@ function SuspenseTimelineInput({rootID}: {rootID: Element['id'] | void}) {
     setValue(max);
   }
 
+  const markersID = useId();
+  const markers: React.Node[] = useMemo(() => {
+    return timeline.map((suspense, index) => {
+      const takesUpSpace =
+        suspense.rects !== null &&
+        suspense.rects.some(rect => {
+          return rect.width > 0 && rect.height > 0;
+        });
+
+      return takesUpSpace ? (
+        <option
+          key={suspense.id}
+          className={
+            index === value ? styles.SuspenseTimelineActiveMarker : undefined
+          }
+          value={index}>
+          #{index + 1}
+        </option>
+      ) : (
+        <option key={suspense.id} />
+      );
+    });
+  }, [timeline, value]);
+
   if (rootID === undefined) {
     return <div className={styles.SuspenseTimelineInput}>Root not found.</div>;
   }
@@ -188,26 +219,25 @@ function SuspenseTimelineInput({rootID}: {rootID: Element['id'] | void}) {
   }
 
   return (
-    <>
-      <div>
-        {value}/{max}
-      </div>
-      <div className={styles.SuspenseTimelineInput}>
-        <input
-          className={styles.SuspenseTimelineSlider}
-          type="range"
-          min={min}
-          max={max}
-          value={value}
-          onBlur={handleBlur}
-          onChange={handleChange}
-          onFocus={handleFocus}
-          onPointerMove={handlePointerMove}
-          onPointerUp={clearHighlightHostInstance}
-          ref={inputRef}
-        />
-      </div>
-    </>
+    <div className={styles.SuspenseTimelineInput}>
+      <input
+        className={styles.SuspenseTimelineSlider}
+        type="range"
+        min={min}
+        max={max}
+        list={markersID}
+        value={value}
+        onBlur={handleBlur}
+        onChange={handleChange}
+        onFocus={handleFocus}
+        onPointerMove={handlePointerMove}
+        onPointerUp={clearHighlightHostInstance}
+        ref={inputRef}
+      />
+      <datalist id={markersID} className={styles.SuspenseTimelineMarkers}>
+        {markers}
+      </datalist>
+    </div>
   );
 }
 

packages/react-devtools-shared/src/devtools/views/SuspenseTab/SuspenseTreeList.js

@@ -10,5 +10,5 @@
 import * as React from 'react';
 
 export default function SuspenseTreeList(_: {}): React$Node {
-  return <div>Activity slices not implemented yet</div>;
+  return <div>Activity slices</div>;
 }

packages/react-dom/src/client/ReactDOMRootFB.js

@@ -126,7 +126,6 @@ function wwwOnCaughtError(
 
   defaultOnCaughtError(error, errorInfo);
 }
-const noopOnDefaultTransitionIndicator = noop;
 
 export function createRoot(
   container: Element | Document | DocumentFragment,
@@ -138,7 +137,6 @@ export function createRoot(
       ({
         onUncaughtError: wwwOnUncaughtError,
         onCaughtError: wwwOnCaughtError,
-        onDefaultTransitionIndicator: noopOnDefaultTransitionIndicator,
       }: any),
       options,
     ),
@@ -157,7 +155,6 @@ export function hydrateRoot(
       ({
         onUncaughtError: wwwOnUncaughtError,
         onCaughtError: wwwOnCaughtError,
-        onDefaultTransitionIndicator: noopOnDefaultTransitionIndicator,
       }: any),
       options,
     ),
@@ -214,6 +211,7 @@ function getReactRootElementInContainer(container: any) {
 // This isn't reachable because onRecoverableError isn't called in the
 // legacy API.
 const noopOnRecoverableError = noop;
+const noopOnDefaultTransitionIndicator = noop;
 
 function legacyCreateRootFromDOMContainer(
   container: Container,

packages/react-native-renderer/src/ReactFabric.js

@@ -46,10 +46,7 @@ import {
   createPublicRootInstance,
   type PublicRootInstance,
 } from 'react-native/Libraries/ReactPrivate/ReactNativePrivateInterface';
-import {
-  disableLegacyMode,
-  enableDefaultTransitionIndicator,
-} from 'shared/ReactFeatureFlags';
+import {disableLegacyMode} from 'shared/ReactFeatureFlags';
 
 if (typeof ReactFiberErrorDialog.showErrorDialog !== 'function') {
   throw new Error(
@@ -135,12 +132,6 @@ function render(
     if (options && options.onRecoverableError !== undefined) {
       onRecoverableError = options.onRecoverableError;
     }
-    let onDefaultTransitionIndicator = nativeOnDefaultTransitionIndicator;
-    if (enableDefaultTransitionIndicator) {
-      if (options && options.onDefaultTransitionIndicator !== undefined) {
-        onDefaultTransitionIndicator = options.onDefaultTransitionIndicator;
-      }
-    }
 
     const publicRootInstance = createPublicRootInstance(containerTag);
     const rootInstance = {
@@ -160,7 +151,7 @@ function render(
       onUncaughtError,
       onCaughtError,
       onRecoverableError,
-      onDefaultTransitionIndicator,
+      nativeOnDefaultTransitionIndicator,
       null,
     );