[compiler] Tests for different orders of createfrom/capture w/wo function expressions

Adds some typed helpers to represent aliasing, assign, capture, createfrom, and mutate effects along with representative runtime behavior, and then adds tests to demonstrate that we model capture->createfrom and createfrom->capture correctly.

There is one case (createfrom->capture in a lambda) where we infer a less precise effect, but in the more conservative direction (we include more code/deps than necesssary rather than fewer).

.eslintrc.js

@@ -474,7 +474,7 @@ module.exports = {
     {
       files: ['packages/react-server-dom-turbopack/**/*.js'],
       globals: {
-        __turbopack_load_by_url__: 'readonly',
+        __turbopack_load__: 'readonly',
         __turbopack_require__: 'readonly',
       },
     },
@@ -622,7 +622,6 @@ module.exports = {
     ScrollTimeline: 'readonly',
     EventListenerOptionsOrUseCapture: 'readonly',
     FocusOptions: 'readonly',
-    OptionalEffectTiming: 'readonly',
 
     spyOnDev: 'readonly',
     spyOnDevAndProd: 'readonly',

.github/workflows/runtime_build_and_test.yml

@@ -6,12 +6,6 @@ on:
   pull_request:
     paths-ignore:
       - compiler/**
-  workflow_dispatch:
-    inputs:
-      commit_sha:
-        required: false
-        type: string
-        default: ''
 
 permissions: {}
 
@@ -34,7 +28,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - name: Check cache hit
         uses: actions/cache/restore@v4
         id: node_modules
@@ -75,7 +69,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - name: Check cache hit
         uses: actions/cache/restore@v4
         id: node_modules
@@ -123,7 +117,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/github-script@v7
         id: set-matrix
         with:
@@ -142,7 +136,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -172,7 +166,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -204,7 +198,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -260,7 +254,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -307,12 +301,10 @@ jobs:
           path: |
             **/node_modules
           key: runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
-      - name: Install runtime dependencies
-        run: yarn install --frozen-lockfile
-        if: steps.node_modules.outputs.cache-hit != 'true'
-      - name: Install compiler dependencies
-        run: yarn install --frozen-lockfile
-        working-directory: compiler
+          restore-keys: |
+            runtime-and-compiler-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-
+            runtime-and-compiler-node_modules-v6-
+      - run: yarn install --frozen-lockfile
         if: steps.node_modules.outputs.cache-hit != 'true'
       - run: ./scripts/react-compiler/build-compiler.sh && ./scripts/react-compiler/link-compiler.sh
       - run: yarn workspace eslint-plugin-react-hooks test
@@ -331,7 +323,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -426,7 +418,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -471,7 +463,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -499,7 +491,7 @@ jobs:
           merge-multiple: true
       - name: Display structure of build
         run: ls -R build
-      - run: echo ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }} >> build/COMMIT_SHA
+      - run: echo ${{ github.event.pull_request.head.sha || github.sha }} >> build/COMMIT_SHA
       - name: Scrape warning messages
         run: |
           mkdir -p ./build/__test_utils__
@@ -536,7 +528,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -576,7 +568,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -613,7 +605,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -654,7 +646,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -728,7 +720,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -785,7 +777,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -830,7 +822,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.nvmrc'
@@ -879,7 +871,7 @@ jobs:
           node ./scripts/print-warnings/print-warnings.js > build/__test_utils__/ReactAllWarnings.js
       - name: Display structure of build for PR
         run: ls -R build
-      - run: echo ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }} >> build/COMMIT_SHA
+      - run: echo ${{ github.event.pull_request.head.sha || github.sha }} >> build/COMMIT_SHA
       - run: node ./scripts/tasks/danger
       - name: Archive sizebot results
         uses: actions/upload-artifact@v4

.github/workflows/runtime_prereleases.yml

@@ -85,7 +85,7 @@ jobs:
             --skipTests \
             --tags=${{ inputs.dist_tag }} \
             --onlyPackages=${{ inputs.only_packages }} ${{ (inputs.dry && '') || '\'}}
-            ${{ inputs.dry && '--dry' || '' }}
+            ${{ inputs.dry && '--dry'}}
       - if: '${{ inputs.skip_packages }}'
         name: 'Publish all packages EXCEPT ${{ inputs.skip_packages }}'
         run: |
@@ -94,19 +94,19 @@ jobs:
             --skipTests \
             --tags=${{ inputs.dist_tag }} \
             --skipPackages=${{ inputs.skip_packages }} ${{ (inputs.dry && '') || '\'}}
-            ${{ inputs.dry && '--dry' || '' }}
+            ${{ inputs.dry && '--dry'}}
       - if: '${{ !(inputs.skip_packages && inputs.only_packages) }}'
         name: 'Publish all packages'
         run: |
           scripts/release/publish.js \
             --ci \
             --tags=${{ inputs.dist_tag }} ${{ (inputs.dry && '') || '\'}}
-            ${{ inputs.dry && '--dry' || '' }}
+            ${{ inputs.dry && '--dry'}}
       - name: Notify Discord on failure
         if: failure() && inputs.enableFailureNotification == true
         uses: tsickert/discord-webhook@86dc739f3f165f16dadc5666051c367efa1692f4
         with:
           webhook-url: ${{ secrets.DISCORD_WEBHOOK_URL }}
           embed-author-name: "GitHub Actions"
-          embed-title: '[Runtime] Publish of ${{ inputs.release_channel }}@${{ inputs.dist_tag}} release failed'
+          embed-title: 'Publish of $${{ inputs.release_channel }} release failed'
           embed-url: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}/attempts/${{ github.run_attempt }}

.github/workflows/runtime_releases_from_npm_manual.yml

@@ -110,7 +110,7 @@ jobs:
             --tags=${{ inputs.tags }} \
             --publishVersion=${{ inputs.version_to_publish }} \
             --onlyPackages=${{ inputs.only_packages }} ${{ (inputs.dry && '') || '\'}}
-            ${{ inputs.dry && '--dry' || '' }}
+            ${{ inputs.dry && '--dry'}}
       - if: '${{ inputs.skip_packages }}'
         name: 'Publish all packages EXCEPT ${{ inputs.skip_packages }}'
         run: |
@@ -119,7 +119,7 @@ jobs:
             --tags=${{ inputs.tags }} \
             --publishVersion=${{ inputs.version_to_publish }} \
             --skipPackages=${{ inputs.skip_packages }} ${{ (inputs.dry && '') || '\'}}
-            ${{ inputs.dry && '--dry' || '' }}
+            ${{ inputs.dry && '--dry'}}
       - name: Archive released package for debugging
         uses: actions/upload-artifact@v4
         with:

CHANGELOG.md

@@ -19,11 +19,11 @@ An Owner Stack is a string representing the components that are directly respons
 * Updated `useId` to use valid CSS selectors, changing format from `:r123:` to `«r123»`. [#32001](https://github.com/facebook/react/pull/32001)
 * Added a dev-only warning for null/undefined created in useEffect, useInsertionEffect, and useLayoutEffect. [#32355](https://github.com/facebook/react/pull/32355)
 * Fixed a bug where dev-only methods were exported in production builds. React.act is no longer available in production builds. [#32200](https://github.com/facebook/react/pull/32200)
-* Improved consistency across prod and dev to improve compatibility with Google Closure Compiler and bindings [#31808](https://github.com/facebook/react/pull/31808)
+* Improved consistency across prod and dev to improve compatibility with Google Closure Complier and bindings [#31808](https://github.com/facebook/react/pull/31808)
 * Improve passive effect scheduling for consistent task yielding. [#31785](https://github.com/facebook/react/pull/31785)
 * Fixed asserts in React Native when passChildrenWhenCloningPersistedNodes is enabled for OffscreenComponent rendering. [#32528](https://github.com/facebook/react/pull/32528)
 * Fixed component name resolution for Portal [#32640](https://github.com/facebook/react/pull/32640)
-* Added support for beforetoggle and toggle events on the dialog element. [#32479](https://github.com/facebook/react/pull/32479)
+* Added support for beforetoggle and toggle events on the dialog element. #32479 [#32479](https://github.com/facebook/react/pull/32479)
 
 ### React DOM
 * Fixed double warning when the `href` attribute is an empty string [#31783](https://github.com/facebook/react/pull/31783)

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

@@ -44,7 +44,6 @@ import {
   PrintedCompilerPipelineValue,
 } from './Output';
 import {transformFromAstSync} from '@babel/core';
-import {LoggerEvent} from 'babel-plugin-react-compiler/dist/Entrypoint';
 
 function parseInput(
   input: string,
@@ -144,7 +143,6 @@ const COMMON_HOOKS: Array<[string, Hook]> = [
 function compile(source: string): [CompilerOutput, 'flow' | 'typescript'] {
   const results = new Map<string, Array<PrintedCompilerPipelineValue>>();
   const error = new CompilerError();
-  const otherErrors: Array<CompilerErrorDetail> = [];
   const upsert: (result: PrintedCompilerPipelineValue) => void = result => {
     const entry = results.get(result.name);
     if (Array.isArray(entry)) {
@@ -212,11 +210,7 @@ function compile(source: string): [CompilerOutput, 'flow' | 'typescript'] {
       },
       logger: {
         debugLogIRs: logIR,
-        logEvent: (_filename: string | null, event: LoggerEvent) => {
-          if (event.kind === 'CompileError') {
-            otherErrors.push(new CompilerErrorDetail(event.detail));
-          }
-        },
+        logEvent: () => {},
       },
     });
     transformOutput = invokeCompiler(source, language, opts);
@@ -243,10 +237,6 @@ function compile(source: string): [CompilerOutput, 'flow' | 'typescript'] {
       );
     }
   }
-  // Only include logger errors if there weren't other errors
-  if (!error.hasErrors() && otherErrors.length !== 0) {
-    otherErrors.forEach(e => error.push(e));
-  }
   if (error.hasErrors()) {
     return [{kind: 'err', results, error: error}, language];
   }

compiler/packages/babel-plugin-react-compiler/src/Babel/BabelPlugin.ts

@@ -12,7 +12,6 @@ import {
   pipelineUsesReanimatedPlugin,
 } from '../Entrypoint/Reanimated';
 import validateNoUntransformedReferences from '../Entrypoint/ValidateNoUntransformedReferences';
-import {CompilerError} from '..';
 
 const ENABLE_REACT_COMPILER_TIMINGS =
   process.env['ENABLE_REACT_COMPILER_TIMINGS'] === '1';
@@ -35,58 +34,51 @@ export default function BabelPluginReactCompiler(
        */
       Program: {
         enter(prog, pass): void {
-          try {
-            const filename = pass.filename ?? 'unknown';
-            if (ENABLE_REACT_COMPILER_TIMINGS === true) {
-              performance.mark(`${filename}:start`, {
-                detail: 'BabelPlugin:Program:start',
-              });
-            }
-            let opts = parsePluginOptions(pass.opts);
-            const isDev =
-              (typeof __DEV__ !== 'undefined' && __DEV__ === true) ||
-              process.env['NODE_ENV'] === 'development';
-            if (
-              opts.enableReanimatedCheck === true &&
-              pipelineUsesReanimatedPlugin(pass.file.opts.plugins)
-            ) {
-              opts = injectReanimatedFlag(opts);
-            }
-            if (
-              opts.environment.enableResetCacheOnSourceFileChanges !== false &&
-              isDev
-            ) {
-              opts = {
-                ...opts,
-                environment: {
-                  ...opts.environment,
-                  enableResetCacheOnSourceFileChanges: true,
-                },
-              };
-            }
-            const result = compileProgram(prog, {
-              opts,
-              filename: pass.filename ?? null,
-              comments: pass.file.ast.comments ?? [],
-              code: pass.file.code,
+          const filename = pass.filename ?? 'unknown';
+          if (ENABLE_REACT_COMPILER_TIMINGS === true) {
+            performance.mark(`${filename}:start`, {
+              detail: 'BabelPlugin:Program:start',
+            });
+          }
+          let opts = parsePluginOptions(pass.opts);
+          const isDev =
+            (typeof __DEV__ !== 'undefined' && __DEV__ === true) ||
+            process.env['NODE_ENV'] === 'development';
+          if (
+            opts.enableReanimatedCheck === true &&
+            pipelineUsesReanimatedPlugin(pass.file.opts.plugins)
+          ) {
+            opts = injectReanimatedFlag(opts);
+          }
+          if (
+            opts.environment.enableResetCacheOnSourceFileChanges !== false &&
+            isDev
+          ) {
+            opts = {
+              ...opts,
+              environment: {
+                ...opts.environment,
+                enableResetCacheOnSourceFileChanges: true,
+              },
+            };
+          }
+          const result = compileProgram(prog, {
+            opts,
+            filename: pass.filename ?? null,
+            comments: pass.file.ast.comments ?? [],
+            code: pass.file.code,
+          });
+          validateNoUntransformedReferences(
+            prog,
+            pass.filename ?? null,
+            opts.logger,
+            opts.environment,
+            result,
+          );
+          if (ENABLE_REACT_COMPILER_TIMINGS === true) {
+            performance.mark(`${filename}:end`, {
+              detail: 'BabelPlugin:Program:end',
             });
-            validateNoUntransformedReferences(
-              prog,
-              pass.filename ?? null,
-              opts.logger,
-              opts.environment,
-              result,
-            );
-            if (ENABLE_REACT_COMPILER_TIMINGS === true) {
-              performance.mark(`${filename}:end`, {
-                detail: 'BabelPlugin:Program:end',
-              });
-            }
-          } catch (e) {
-            if (e instanceof CompilerError) {
-              throw new Error(e.printErrorMessage(pass.file.code));
-            }
-            throw e;
           }
         },
         exit(_, pass): void {

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

@@ -5,7 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {codeFrameColumns} from '@babel/code-frame';
 import type {SourceLocation} from './HIR';
 import {Err, Ok, Result} from './Utils/Result';
 import {assertExhaustive} from './Utils/utils';
@@ -16,11 +15,6 @@ export enum ErrorSeverity {
    * misunderstanding on the user’s part.
    */
   InvalidJS = 'InvalidJS',
-  /**
-   * JS syntax that is not supported and which we do not plan to support. Developers should
-   * rewrite to use supported forms.
-   */
-  UnsupportedJS = 'UnsupportedJS',
   /**
    * Code that breaks the rules of React.
    */
@@ -45,24 +39,6 @@ export enum ErrorSeverity {
   Invariant = 'Invariant',
 }
 
-export type CompilerDiagnosticOptions = {
-  severity: ErrorSeverity;
-  category: string;
-  description: string;
-  details: Array<CompilerDiagnosticDetail>;
-  suggestions?: Array<CompilerSuggestion> | null | undefined;
-};
-
-export type CompilerDiagnosticDetail =
-  /**
-   * A/the source of the error
-   */
-  {
-    kind: 'error';
-    loc: SourceLocation;
-    message: string;
-  };
-
 export enum CompilerSuggestionOperation {
   InsertBefore,
   InsertAfter,
@@ -93,94 +69,6 @@ export type CompilerErrorDetailOptions = {
   suggestions?: Array<CompilerSuggestion> | null | undefined;
 };
 
-export class CompilerDiagnostic {
-  options: CompilerDiagnosticOptions;
-
-  constructor(options: CompilerDiagnosticOptions) {
-    this.options = options;
-  }
-
-  get category(): CompilerDiagnosticOptions['category'] {
-    return this.options.category;
-  }
-  get description(): CompilerDiagnosticOptions['description'] {
-    return this.options.description;
-  }
-  get severity(): CompilerDiagnosticOptions['severity'] {
-    return this.options.severity;
-  }
-  get suggestions(): CompilerDiagnosticOptions['suggestions'] {
-    return this.options.suggestions;
-  }
-
-  primaryLocation(): SourceLocation | null {
-    return this.options.details.filter(d => d.kind === 'error')[0]?.loc ?? null;
-  }
-
-  printErrorMessage(source: string): string {
-    const buffer = [
-      printErrorSummary(this.severity, this.category),
-      '\n\n',
-      this.description,
-    ];
-    for (const detail of this.options.details) {
-      switch (detail.kind) {
-        case 'error': {
-          const loc = detail.loc;
-          if (typeof loc === 'symbol') {
-            continue;
-          }
-          let codeFrame: string;
-          try {
-            codeFrame = codeFrameColumns(
-              source,
-              {
-                start: {
-                  line: loc.start.line,
-                  column: loc.start.column + 1,
-                },
-                end: {
-                  line: loc.end.line,
-                  column: loc.end.column + 1,
-                },
-              },
-              {
-                message: detail.message,
-              },
-            );
-          } catch (e) {
-            codeFrame = detail.message;
-          }
-          buffer.push(
-            `\n\n${loc.filename}:${loc.start.line}:${loc.start.column}\n`,
-          );
-          buffer.push(codeFrame);
-          break;
-        }
-        default: {
-          assertExhaustive(
-            detail.kind,
-            `Unexpected detail kind ${(detail as any).kind}`,
-          );
-        }
-      }
-    }
-    return buffer.join('');
-  }
-
-  toString(): string {
-    const buffer = [printErrorSummary(this.severity, this.category)];
-    if (this.description != null) {
-      buffer.push(`. ${this.description}.`);
-    }
-    const loc = this.primaryLocation();
-    if (loc != null && typeof loc !== 'symbol') {
-      buffer.push(` (${loc.start.line}:${loc.start.column})`);
-    }
-    return buffer.join('');
-  }
-}
-
 /*
  * Each bailout or invariant in HIR lowering creates an {@link CompilerErrorDetail}, which is then
  * aggregated into a single {@link CompilerError} later.
@@ -208,62 +96,24 @@ export class CompilerErrorDetail {
     return this.options.suggestions;
   }
 
-  primaryLocation(): SourceLocation | null {
-    return this.loc;
-  }
-
-  printErrorMessage(source: string): string {
-    const buffer = [printErrorSummary(this.severity, this.reason)];
+  printErrorMessage(): string {
+    const buffer = [`${this.severity}: ${this.reason}`];
     if (this.description != null) {
-      buffer.push(`\n\n${this.description}.`);
+      buffer.push(`. ${this.description}`);
     }
-    const loc = this.loc;
-    if (loc != null && typeof loc !== 'symbol') {
-      let codeFrame: string;
-      try {
-        codeFrame = codeFrameColumns(
-          source,
-          {
-            start: {
-              line: loc.start.line,
-              column: loc.start.column + 1,
-            },
-            end: {
-              line: loc.end.line,
-              column: loc.end.column + 1,
-            },
-          },
-          {
-            message: this.reason,
-          },
-        );
-      } catch (e) {
-        codeFrame = '';
-      }
-      buffer.push(
-        `\n\n${loc.filename}:${loc.start.line}:${loc.start.column}\n`,
-      );
-      buffer.push(codeFrame);
-      buffer.push('\n\n');
+    if (this.loc != null && typeof this.loc !== 'symbol') {
+      buffer.push(` (${this.loc.start.line}:${this.loc.end.line})`);
     }
     return buffer.join('');
   }
 
   toString(): string {
-    const buffer = [printErrorSummary(this.severity, this.reason)];
-    if (this.description != null) {
-      buffer.push(`. ${this.description}.`);
-    }
-    const loc = this.loc;
-    if (loc != null && typeof loc !== 'symbol') {
-      buffer.push(` (${loc.start.line}:${loc.start.column})`);
-    }
-    return buffer.join('');
+    return this.printErrorMessage();
   }
 }
 
 export class CompilerError extends Error {
-  details: Array<CompilerErrorDetail | CompilerDiagnostic> = [];
+  details: Array<CompilerErrorDetail> = [];
 
   static invariant(
     condition: unknown,
@@ -281,12 +131,6 @@ export class CompilerError extends Error {
     }
   }
 
-  static throwDiagnostic(options: CompilerDiagnosticOptions): never {
-    const errors = new CompilerError();
-    errors.pushDiagnostic(new CompilerDiagnostic(options));
-    throw errors;
-  }
-
   static throwTodo(
     options: Omit<CompilerErrorDetailOptions, 'severity'>,
   ): never {
@@ -361,21 +205,6 @@ export class CompilerError extends Error {
     return this.name;
   }
 
-  printErrorMessage(source: string): string {
-    return (
-      `Found ${this.details.length} error${this.details.length === 1 ? '' : 's'}:\n` +
-      this.details.map(detail => detail.printErrorMessage(source)).join('\n')
-    );
-  }
-
-  merge(other: CompilerError): void {
-    this.details.push(...other.details);
-  }
-
-  pushDiagnostic(diagnostic: CompilerDiagnostic): void {
-    this.details.push(diagnostic);
-  }
-
   push(options: CompilerErrorDetailOptions): CompilerErrorDetail {
     const detail = new CompilerErrorDetail({
       reason: options.reason,
@@ -412,46 +241,13 @@ export class CompilerError extends Error {
         case ErrorSeverity.InvalidJS:
         case ErrorSeverity.InvalidReact:
         case ErrorSeverity.InvalidConfig:
-        case ErrorSeverity.UnsupportedJS: {
           return true;
-        }
         case ErrorSeverity.CannotPreserveMemoization:
-        case ErrorSeverity.Todo: {
+        case ErrorSeverity.Todo:
           return false;
-        }
-        default: {
+        default:
           assertExhaustive(detail.severity, 'Unhandled error severity');
-        }
       }
     });
   }
 }
-
-function printErrorSummary(severity: ErrorSeverity, message: string): string {
-  let severityCategory: string;
-  switch (severity) {
-    case ErrorSeverity.InvalidConfig:
-    case ErrorSeverity.InvalidJS:
-    case ErrorSeverity.InvalidReact:
-    case ErrorSeverity.UnsupportedJS: {
-      severityCategory = 'Error';
-      break;
-    }
-    case ErrorSeverity.CannotPreserveMemoization: {
-      severityCategory = 'Memoization';
-      break;
-    }
-    case ErrorSeverity.Invariant: {
-      severityCategory = 'Invariant';
-      break;
-    }
-    case ErrorSeverity.Todo: {
-      severityCategory = 'Todo';
-      break;
-    }
-    default: {
-      assertExhaustive(severity, `Unexpected severity '${severity}'`);
-    }
-  }
-  return `${severityCategory}: ${message}`;
-}

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

@@ -7,12 +7,7 @@
 
 import * as t from '@babel/types';
 import {z} from 'zod';
-import {
-  CompilerDiagnostic,
-  CompilerError,
-  CompilerErrorDetail,
-  CompilerErrorDetailOptions,
-} from '../CompilerError';
+import {CompilerError, CompilerErrorDetailOptions} from '../CompilerError';
 import {
   EnvironmentConfig,
   ExternalFunction,
@@ -229,7 +224,7 @@ export type LoggerEvent =
 export type CompileErrorEvent = {
   kind: 'CompileError';
   fnLoc: t.SourceLocation | null;
-  detail: CompilerErrorDetail | CompilerDiagnostic;
+  detail: CompilerErrorDetailOptions;
 };
 export type CompileDiagnosticEvent = {
   kind: 'CompileDiagnostic';

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

@@ -94,7 +94,7 @@ import {validateLocalsNotReassignedAfterRender} from '../Validation/ValidateLoca
 import {outlineFunctions} from '../Optimization/OutlineFunctions';
 import {propagatePhiTypes} from '../TypeInference/PropagatePhiTypes';
 import {lowerContextAccess} from '../Optimization/LowerContextAccess';
-import {validateNoSetStateInEffects} from '../Validation/ValidateNoSetStateInEffects';
+import {validateNoSetStateInPassiveEffects} from '../Validation/ValidateNoSetStateInPassiveEffects';
 import {validateNoJSXInTryStatement} from '../Validation/ValidateNoJSXInTryStatement';
 import {propagateScopeDependenciesHIR} from '../HIR/PropagateScopeDependenciesHIR';
 import {outlineJSX} from '../Optimization/OutlineJsx';
@@ -292,8 +292,8 @@ function runWithEnvironment(
       validateNoSetStateInRender(hir).unwrap();
     }
 
-    if (env.config.validateNoSetStateInEffects) {
-      env.logErrors(validateNoSetStateInEffects(hir));
+    if (env.config.validateNoSetStateInPassiveEffects) {
+      env.logErrors(validateNoSetStateInPassiveEffects(hir));
     }
 
     if (env.config.validateNoJSXInTryStatements) {

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

@@ -181,7 +181,7 @@ function logError(
         context.opts.logger.logEvent(context.filename, {
           kind: 'CompileError',
           fnLoc,
-          detail,
+          detail: detail.options,
         });
       }
     } else {

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

@@ -8,63 +8,35 @@
 import {NodePath} from '@babel/core';
 import * as t from '@babel/types';
 
-import {CompilerError, EnvironmentConfig, ErrorSeverity, Logger} from '..';
+import {
+  CompilerError,
+  CompilerErrorDetailOptions,
+  EnvironmentConfig,
+  ErrorSeverity,
+  Logger,
+} from '..';
 import {getOrInsertWith} from '../Utils/utils';
-import {Environment, GeneratedSource} from '../HIR';
+import {Environment} from '../HIR';
 import {DEFAULT_EXPORT} from '../HIR/Environment';
 import {CompileProgramMetadata} from './Program';
-import {CompilerDiagnostic, CompilerDiagnosticOptions} from '../CompilerError';
 
 function throwInvalidReact(
-  options: Omit<CompilerDiagnosticOptions, 'severity'>,
+  options: Omit<CompilerErrorDetailOptions, 'severity'>,
   {logger, filename}: TraversalState,
 ): never {
-  const detail: CompilerDiagnosticOptions = {
-    severity: ErrorSeverity.InvalidReact,
+  const detail: CompilerErrorDetailOptions = {
     ...options,
+    severity: ErrorSeverity.InvalidReact,
   };
   logger?.logEvent(filename, {
     kind: 'CompileError',
     fnLoc: null,
-    detail: new CompilerDiagnostic(detail),
+    detail,
   });
-  CompilerError.throwDiagnostic(detail);
-}
-
-function isAutodepsSigil(
-  arg: NodePath<t.ArgumentPlaceholder | t.SpreadElement | t.Expression>,
-): boolean {
-  // Check for AUTODEPS identifier imported from React
-  if (arg.isIdentifier() && arg.node.name === 'AUTODEPS') {
-    const binding = arg.scope.getBinding(arg.node.name);
-    if (binding && binding.path.isImportSpecifier()) {
-      const importSpecifier = binding.path.node as t.ImportSpecifier;
-      if (importSpecifier.imported.type === 'Identifier') {
-        return (importSpecifier.imported as t.Identifier).name === 'AUTODEPS';
-      }
-    }
-    return false;
-  }
-
-  // Check for React.AUTODEPS member expression
-  if (arg.isMemberExpression() && !arg.node.computed) {
-    const object = arg.get('object');
-    const property = arg.get('property');
-
-    if (
-      object.isIdentifier() &&
-      object.node.name === 'React' &&
-      property.isIdentifier() &&
-      property.node.name === 'AUTODEPS'
-    ) {
-      return true;
-    }
-  }
-
-  return false;
+  CompilerError.throw(detail);
 }
 function assertValidEffectImportReference(
-  autodepsIndex: number,
+  numArgs: number,
   paths: Array<NodePath<t.Node>>,
   context: TraversalState,
 ): void {
@@ -77,10 +49,11 @@ function assertValidEffectImportReference(
         maybeCalleeLoc != null &&
         context.inferredEffectLocations.has(maybeCalleeLoc);
       /**
-       * Error on effect calls that still have AUTODEPS in their args
+       * Only error on untransformed references of the form `useMyEffect(...)`
+       * or `moduleNamespace.useMyEffect(...)`, with matching argument counts.
+       * TODO: do we also want a mode to also hard error on non-call references?
        */
-      const hasAutodepsArg = args.some(isAutodepsSigil);
-      if (hasAutodepsArg && !hasInferredEffect) {
+      if (args.length === numArgs && !hasInferredEffect) {
         const maybeErrorDiagnostic = matchCompilerDiagnostic(
           path,
           context.transformErrors,
@@ -92,18 +65,14 @@ function assertValidEffectImportReference(
          */
         throwInvalidReact(
           {
-            category:
-              'Cannot infer dependencies of this effect. This will break your build!',
-            description:
-              'To resolve, either pass a dependency array or fix reported compiler bailout diagnostics.' +
-              (maybeErrorDiagnostic ? ` ${maybeErrorDiagnostic}` : ''),
-            details: [
-              {
-                kind: 'error',
-                message: 'Cannot infer dependencies',
-                loc: parent.node.loc ?? GeneratedSource,
-              },
-            ],
+            reason:
+              '[InferEffectDependencies] React Compiler is unable to infer dependencies of this effect. ' +
+              'This will break your build! ' +
+              'To resolve, either pass your own dependency array or fix reported compiler bailout diagnostics.',
+            description: maybeErrorDiagnostic
+              ? `(Bailout reason: ${maybeErrorDiagnostic})`
+              : null,
+            loc: parent.node.loc ?? null,
           },
           context,
         );
@@ -123,20 +92,13 @@ function assertValidFireImportReference(
     );
     throwInvalidReact(
       {
-        category:
-          '[Fire] Untransformed reference to compiler-required feature.',
-        description:
-          'Either remove this `fire` call or ensure it is successfully transformed by the compiler' +
-          maybeErrorDiagnostic
-            ? ` ${maybeErrorDiagnostic}`
-            : '',
-        details: [
-          {
-            kind: 'error',
-            message: 'Untransformed `fire` call',
-            loc: paths[0].node.loc ?? GeneratedSource,
-          },
-        ],
+        reason:
+          '[Fire] Untransformed reference to compiler-required feature. ' +
+          'Either remove this `fire` call or ensure it is successfully transformed by the compiler',
+        description: maybeErrorDiagnostic
+          ? `(Bailout reason: ${maybeErrorDiagnostic})`
+          : null,
+        loc: paths[0].node.loc ?? null,
       },
       context,
     );
@@ -166,12 +128,12 @@ export default function validateNoUntransformedReferences(
   if (env.inferEffectDependencies) {
     for (const {
       function: {source, importSpecifierName},
-      autodepsIndex,
+      numRequiredArgs,
     } of env.inferEffectDependencies) {
       const module = getOrInsertWith(moduleLoadChecks, source, () => new Map());
       module.set(
         importSpecifierName,
-        assertValidEffectImportReference.bind(null, autodepsIndex),
+        assertValidEffectImportReference.bind(null, numRequiredArgs),
       );
     }
   }

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

@@ -221,6 +221,7 @@ export function lower(
     params,
     fnType: bindings == null ? env.fnType : 'Other',
     returnTypeAnnotation: null, // TODO: extract the actual return type node if present
+    returnType: makeType(),
     returns: createTemporaryPlace(env, func.node.loc ?? GeneratedSource),
     body: builder.build(),
     context,
@@ -1355,85 +1356,13 @@ function lowerStatement(
 
       return;
     }
-    case 'WithStatement': {
-      builder.errors.push({
-        reason: `JavaScript 'with' syntax is not supported`,
-        description: `'with' syntax is considered deprecated and removed from JavaScript standards, consider alternatives`,
-        severity: ErrorSeverity.UnsupportedJS,
-        loc: stmtPath.node.loc ?? null,
-        suggestions: null,
-      });
-      lowerValueToTemporary(builder, {
-        kind: 'UnsupportedNode',
-        loc: stmtPath.node.loc ?? GeneratedSource,
-        node: stmtPath.node,
-      });
-      return;
-    }
-    case 'ClassDeclaration': {
-      /**
-       * In theory we could support inline class declarations, but this is rare enough in practice
-       * and complex enough to support that we don't anticipate supporting anytime soon. Developers
-       * are encouraged to lift classes out of component/hook declarations.
-       */
-      builder.errors.push({
-        reason: 'Inline `class` declarations are not supported',
-        description: `Move class declarations outside of components/hooks`,
-        severity: ErrorSeverity.UnsupportedJS,
-        loc: stmtPath.node.loc ?? null,
-        suggestions: null,
-      });
-      lowerValueToTemporary(builder, {
-        kind: 'UnsupportedNode',
-        loc: stmtPath.node.loc ?? GeneratedSource,
-        node: stmtPath.node,
-      });
-      return;
-    }
-    case 'EnumDeclaration':
-    case 'TSEnumDeclaration': {
-      lowerValueToTemporary(builder, {
-        kind: 'UnsupportedNode',
-        loc: stmtPath.node.loc ?? GeneratedSource,
-        node: stmtPath.node,
-      });
-      return;
-    }
-    case 'ExportAllDeclaration':
-    case 'ExportDefaultDeclaration':
-    case 'ExportNamedDeclaration':
-    case 'ImportDeclaration':
-    case 'TSExportAssignment':
-    case 'TSImportEqualsDeclaration': {
-      builder.errors.push({
-        reason:
-          'JavaScript `import` and `export` statements may only appear at the top level of a module',
-        severity: ErrorSeverity.InvalidJS,
-        loc: stmtPath.node.loc ?? null,
-        suggestions: null,
-      });
-      lowerValueToTemporary(builder, {
-        kind: 'UnsupportedNode',
-        loc: stmtPath.node.loc ?? GeneratedSource,
-        node: stmtPath.node,
-      });
-      return;
-    }
-    case 'TSNamespaceExportDeclaration': {
-      builder.errors.push({
-        reason:
-          'TypeScript `namespace` statements may only appear at the top level of a module',
-        severity: ErrorSeverity.InvalidJS,
-        loc: stmtPath.node.loc ?? null,
-        suggestions: null,
-      });
-      lowerValueToTemporary(builder, {
-        kind: 'UnsupportedNode',
-        loc: stmtPath.node.loc ?? GeneratedSource,
-        node: stmtPath.node,
-      });
+    case 'TypeAlias':
+    case 'TSInterfaceDeclaration':
+    case 'TSTypeAliasDeclaration': {
+      // We do not preserve type annotations/syntax through transformation
       return;
     }
+    case 'ClassDeclaration':
     case 'DeclareClass':
     case 'DeclareExportAllDeclaration':
     case 'DeclareExportDeclaration':
@@ -1444,14 +1373,31 @@ function lowerStatement(
     case 'DeclareOpaqueType':
     case 'DeclareTypeAlias':
     case 'DeclareVariable':
+    case 'EnumDeclaration':
+    case 'ExportAllDeclaration':
+    case 'ExportDefaultDeclaration':
+    case 'ExportNamedDeclaration':
+    case 'ImportDeclaration':
     case 'InterfaceDeclaration':
     case 'OpaqueType':
     case 'TSDeclareFunction':
-    case 'TSInterfaceDeclaration':
+    case 'TSEnumDeclaration':
+    case 'TSExportAssignment':
+    case 'TSImportEqualsDeclaration':
     case 'TSModuleDeclaration':
-    case 'TSTypeAliasDeclaration':
-    case 'TypeAlias': {
-      // We do not preserve type annotations/syntax through transformation
+    case 'TSNamespaceExportDeclaration':
+    case 'WithStatement': {
+      builder.errors.push({
+        reason: `(BuildHIR::lowerStatement) Handle ${stmtPath.type} statements`,
+        severity: ErrorSeverity.Todo,
+        loc: stmtPath.node.loc ?? null,
+        suggestions: null,
+      });
+      lowerValueToTemporary(builder, {
+        kind: 'UnsupportedNode',
+        loc: stmtPath.node.loc ?? GeneratedSource,
+        node: stmtPath.node,
+      });
       return;
     }
     default: {
@@ -2271,17 +2217,11 @@ function lowerExpression(
         });
         for (const [name, locations] of Object.entries(fbtLocations)) {
           if (locations.length > 1) {
-            CompilerError.throwDiagnostic({
-              severity: ErrorSeverity.Todo,
-              category: 'Support duplicate fbt tags',
-              description: `Support \`<${tagName}>\` tags with multiple \`<${tagName}:${name}>\` values`,
-              details: locations.map(loc => {
-                return {
-                  kind: 'error',
-                  message: `Multiple \`<${tagName}:${name}>\` tags found`,
-                  loc,
-                };
-              }),
+            CompilerError.throwTodo({
+              reason: `Support <${tagName}> tags with multiple <${tagName}:${name}> values`,
+              loc: locations.at(-1) ?? GeneratedSource,
+              description: null,
+              suggestions: null,
             });
           }
         }
@@ -3007,8 +2947,6 @@ function isReorderableExpression(
         }
       }
     }
-    case 'TSAsExpression':
-    case 'TSNonNullExpression':
     case 'TypeCastExpression': {
       return isReorderableExpression(
         builder,
@@ -3509,8 +3447,9 @@ function lowerFunction(
   );
   let loweredFunc: HIRFunction;
   if (lowering.isErr()) {
-    const functionErrors = lowering.unwrapErr();
-    builder.errors.merge(functionErrors);
+    lowering
+      .unwrapErr()
+      .details.forEach(detail => builder.errors.pushErrorDetail(detail));
     return null;
   }
   loweredFunc = lowering.unwrap();
@@ -3564,16 +3503,6 @@ function lowerIdentifier(
       return place;
     }
     default: {
-      if (binding.kind === 'Global' && binding.name === 'eval') {
-        builder.errors.push({
-          reason: `The 'eval' function is not supported`,
-          description:
-            'Eval is an anti-pattern in JavaScript, and the code executed cannot be evaluated by React Compiler',
-          severity: ErrorSeverity.UnsupportedJS,
-          loc: exprPath.node.loc ?? null,
-          suggestions: null,
-        });
-      }
       return lowerValueToTemporary(builder, {
         kind: 'LoadGlobal',
         binding,

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

@@ -265,19 +265,21 @@ export const EnvironmentConfigSchema = z.object({
    *   {
    *     module: 'react',
    *     imported: 'useEffect',
-   *     autodepsIndex: 1,
+   *     numRequiredArgs: 1,
    *   },{
    *     module: 'MyExperimentalEffectHooks',
    *     imported: 'useExperimentalEffect',
-   *     autodepsIndex: 2,
+   *     numRequiredArgs: 2,
    *   },
    * ]
    * would insert dependencies for calls of `useEffect` imported from `react` and calls of
    * useExperimentalEffect` from `MyExperimentalEffectHooks`.
    *
-   * `autodepsIndex` tells the compiler which index we expect the AUTODEPS to appear in.
-   *  With the configuration above, we'd insert dependencies for `useEffect` if it has two
-   *  arguments, and the second is AUTODEPS.
+   * `numRequiredArgs` tells the compiler the amount of arguments required to append a dependency
+   *  array to the end of the call. With the configuration above, we'd insert dependencies for
+   *  `useEffect` if it is only given a single argument and it would be appended to the argument list.
+   *
+   * numRequiredArgs must always be greater than 0, otherwise there is no function to analyze for dependencies
    *
    * Still experimental.
    */
@@ -286,7 +288,7 @@ export const EnvironmentConfigSchema = z.object({
       z.array(
         z.object({
           function: ExternalFunctionSchema,
-          autodepsIndex: z.number().min(1, 'autodepsIndex must be > 0'),
+          numRequiredArgs: z.number().min(1, 'numRequiredArgs must be > 0'),
         }),
       ),
     )
@@ -318,10 +320,10 @@ export const EnvironmentConfigSchema = z.object({
   validateNoSetStateInRender: z.boolean().default(true),
 
   /**
-   * Validates that setState is not called synchronously within an effect (useEffect and friends).
+   * Validates that setState is not called directly within a passive effect (useEffect).
    * Scheduling a setState (with an event listener, subscription, etc) is valid.
    */
-  validateNoSetStateInEffects: z.boolean().default(false),
+  validateNoSetStateInPassiveEffects: z.boolean().default(false),
 
   /**
    * Validates against creating JSX within a try block and recommends using an error boundary

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

@@ -9,7 +9,6 @@ import {Effect, ValueKind, ValueReason} from './HIR';
 import {
   BUILTIN_SHAPES,
   BuiltInArrayId,
-  BuiltInAutodepsId,
   BuiltInFireFunctionId,
   BuiltInFireId,
   BuiltInMapId,
@@ -781,7 +780,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       BuiltInUseEffectEventId,
     ),
   ],
-  ['AUTODEPS', addObject(DEFAULT_SHAPES, BuiltInAutodepsId, [])],
 ];
 
 TYPED_GLOBALS.push(

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

@@ -279,6 +279,7 @@ export type HIRFunction = {
   env: Environment;
   params: Array<Place | SpreadPattern>;
   returnTypeAnnotation: t.FlowType | t.TSType | null;
+  returnType: Type;
   returns: Place;
   context: Array<Place>;
   effects: Array<FunctionEffect> | null;
@@ -1769,10 +1770,6 @@ export function isUseStateType(id: Identifier): boolean {
   return id.type.kind === 'Object' && id.type.shapeId === 'BuiltInUseState';
 }
 
-export function isJsxType(type: Type): boolean {
-  return type.kind === 'Object' && type.shapeId === 'BuiltInJsx';
-}
-
 export function isRefOrRefValue(id: Identifier): boolean {
   return isUseRefType(id) || isRefValueType(id);
 }

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

@@ -7,7 +7,7 @@
 
 import {Binding, NodePath} from '@babel/traverse';
 import * as t from '@babel/types';
-import {CompilerError, ErrorSeverity} from '../CompilerError';
+import {CompilerError} from '../CompilerError';
 import {Environment} from './Environment';
 import {
   BasicBlock,
@@ -308,18 +308,9 @@ export default class HIRBuilder {
 
   resolveBinding(node: t.Identifier): Identifier {
     if (node.name === 'fbt') {
-      CompilerError.throwDiagnostic({
-        severity: ErrorSeverity.Todo,
-        category: 'Support local variables named `fbt`',
-        description:
-          'Local variables named `fbt` may conflict with the fbt plugin and are not yet supported',
-        details: [
-          {
-            kind: 'error',
-            message: 'Rename to avoid conflict with fbt plugin',
-            loc: node.loc ?? GeneratedSource,
-          },
-        ],
+      CompilerError.throwTodo({
+        reason: 'Support local variables named "fbt"',
+        loc: node.loc ?? null,
       });
     }
     const originalName = node.name;

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

@@ -107,17 +107,6 @@ export function mergeConsecutiveBlocks(fn: HIRFunction): void {
     merged.merge(block.id, predecessorId);
     fn.body.blocks.delete(block.id);
   }
-  for (const [, block] of fn.body.blocks) {
-    for (const phi of block.phis) {
-      for (const [predecessorId, operand] of phi.operands) {
-        const mapped = merged.get(predecessorId);
-        if (mapped !== predecessorId) {
-          phi.operands.delete(predecessorId);
-          phi.operands.set(mapped, operand);
-        }
-      }
-    }
-  }
   markPredecessors(fn.body);
   for (const [, {terminal}] of fn.body.blocks) {
     if (terminalHasFallthrough(terminal)) {

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

@@ -384,7 +384,6 @@ export const BuiltInFireId = 'BuiltInFire';
 export const BuiltInFireFunctionId = 'BuiltInFireFunction';
 export const BuiltInUseEffectEventId = 'BuiltInUseEffectEvent';
 export const BuiltinEffectEventId = 'BuiltInEffectEventFunction';
-export const BuiltInAutodepsId = 'BuiltInAutoDepsId';
 
 // See getReanimatedModuleType() in Globals.ts — this is part of supporting Reanimated's ref-like types
 export const ReanimatedSharedValueId = 'ReanimatedSharedValueId';

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

@@ -5,6 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import generate from '@babel/generator';
 import {CompilerError} from '../CompilerError';
 import {printReactiveScopeSummary} from '../ReactiveScopes/PrintReactiveFunction';
 import DisjointSet from '../Utils/DisjointSet';
@@ -53,8 +54,6 @@ export function printFunction(fn: HIRFunction): string {
   let definition = '';
   if (fn.id !== null) {
     definition += fn.id;
-  } else {
-    definition += '<<anonymous>>';
   }
   if (fn.params.length !== 0) {
     definition +=
@@ -72,8 +71,10 @@ export function printFunction(fn: HIRFunction): string {
   } else {
     definition += '()';
   }
-  definition += `: ${printPlace(fn.returns)}`;
-  output.push(definition);
+  if (definition.length !== 0) {
+    output.push(definition);
+  }
+  output.push(`: ${printType(fn.returnType)} @ ${printPlace(fn.returns)}`);
   output.push(...fn.directives);
   output.push(printHIR(fn.body));
   return output.join('\n');
@@ -465,7 +466,7 @@ export function printInstructionValue(instrValue: ReactiveValue): string {
       break;
     }
     case 'UnsupportedNode': {
-      value = `UnsupportedNode ${instrValue.node.type}`;
+      value = `UnsupportedNode(${generate(instrValue.node).code})`;
       break;
     }
     case 'LoadLocal': {
@@ -714,7 +715,7 @@ export function printInstructionValue(instrValue: ReactiveValue): string {
       break;
     }
     case 'FinishMemoize': {
-      value = `FinishMemoize decl=${printPlace(instrValue.decl)}${instrValue.pruned ? ' pruned' : ''}`;
+      value = `FinishMemoize decl=${printPlace(instrValue.decl)}`;
       break;
     }
     default: {

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

@@ -22,6 +22,7 @@ import {inferMutableRanges} from './InferMutableRanges';
 import inferReferenceEffects from './InferReferenceEffects';
 import {assertExhaustive} from '../Utils/utils';
 import {inferMutationAliasingEffects} from './InferMutationAliasingEffects';
+import {inferFunctionExpressionAliasingEffectsSignature} from './InferFunctionExpressionAliasingEffectsSignature';
 import {inferMutationAliasingRanges} from './InferMutationAliasingRanges';
 
 export default function analyseFunctions(func: HIRFunction): void {
@@ -67,12 +68,19 @@ function lowerWithMutationAliasing(fn: HIRFunction): void {
   analyseFunctions(fn);
   inferMutationAliasingEffects(fn, {isFunctionExpression: true});
   deadCodeElimination(fn);
-  const functionEffects = inferMutationAliasingRanges(fn, {
-    isFunctionExpression: true,
-  }).unwrap();
+  inferMutationAliasingRanges(fn, {isFunctionExpression: true});
   rewriteInstructionKindsBasedOnReassignment(fn);
   inferReactiveScopeVariables(fn);
-  fn.aliasingEffects = functionEffects;
+  const effects = inferFunctionExpressionAliasingEffectsSignature(fn);
+  fn.env.logger?.debugLogIRs?.({
+    kind: 'hir',
+    name: 'AnalyseFunction (inner)',
+    value: fn,
+  });
+  if (effects != null) {
+    fn.aliasingEffects ??= [];
+    fn.aliasingEffects?.push(...effects);
+  }
 
   /**
    * Phase 2: populate the Effect of each context variable to use in inferring
@@ -80,7 +88,7 @@ function lowerWithMutationAliasing(fn: HIRFunction): void {
    * effects to decide if the function may be mutable or not.
    */
   const capturedOrMutated = new Set<IdentifierId>();
-  for (const effect of functionEffects) {
+  for (const effect of effects ?? []) {
     switch (effect.kind) {
       case 'Assign':
       case 'Alias':
@@ -132,12 +140,6 @@ function lowerWithMutationAliasing(fn: HIRFunction): void {
       operand.effect = Effect.Read;
     }
   }
-
-  fn.env.logger?.debugLogIRs?.({
-    kind: 'hir',
-    name: 'AnalyseFunction (inner)',
-    value: fn,
-  });
 }
 
 function lower(func: HIRFunction): void {

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

@@ -57,8 +57,6 @@ import {
 } from '../HIR/visitors';
 import {empty} from '../Utils/Stack';
 import {getOrInsertWith} from '../Utils/utils';
-import {deadCodeElimination} from '../Optimization';
-import {BuiltInAutodepsId} from '../HIR/ObjectShape';
 
 /**
  * Infers reactive dependencies captured by useEffect lambdas and adds them as
@@ -79,7 +77,7 @@ export function inferEffectDependencies(fn: HIRFunction): void {
     );
     moduleTargets.set(
       effectTarget.function.importSpecifierName,
-      effectTarget.autodepsIndex,
+      effectTarget.numRequiredArgs,
     );
   }
   const autodepFnLoads = new Map<IdentifierId, number>();
@@ -137,6 +135,7 @@ export function inferEffectDependencies(fn: HIRFunction): void {
         }
       } else if (value.kind === 'LoadGlobal') {
         loadGlobals.add(lvalue.identifier.id);
+
         /*
          * TODO: Handle properties on default exports, like
          * import React from 'react';
@@ -170,22 +169,8 @@ export function inferEffectDependencies(fn: HIRFunction): void {
       ) {
         const callee =
           value.kind === 'CallExpression' ? value.callee : value.property;
-
-        const autodepsArgIndex = value.args.findIndex(
-          arg =>
-            arg.kind === 'Identifier' &&
-            arg.identifier.type.kind === 'Object' &&
-            arg.identifier.type.shapeId === BuiltInAutodepsId,
-        );
-        const autodepsArgExpectedIndex = autodepFnLoads.get(
-          callee.identifier.id,
-        );
-
         if (
-          value.args.length > 0 &&
-          autodepsArgExpectedIndex != null &&
-          autodepsArgIndex === autodepsArgExpectedIndex &&
-          autodepFnLoads.has(callee.identifier.id) &&
+          value.args.length === autodepFnLoads.get(callee.identifier.id) &&
           value.args[0].kind === 'Identifier'
         ) {
           // We have a useEffect call with no deps array, so we need to infer the deps
@@ -275,10 +260,7 @@ export function inferEffectDependencies(fn: HIRFunction): void {
                 effects: null,
               },
             });
-            value.args[autodepsArgIndex] = {
-              ...depsPlace,
-              effect: Effect.Freeze,
-            };
+            value.args.push({...depsPlace, effect: Effect.Freeze});
             fn.env.inferredEffectLocations.add(callee.loc);
           } else if (loadGlobals.has(value.args[0].identifier.id)) {
             // Global functions have no reactive dependencies, so we can insert an empty array
@@ -293,10 +275,7 @@ export function inferEffectDependencies(fn: HIRFunction): void {
                 effects: null,
               },
             });
-            value.args[autodepsArgIndex] = {
-              ...depsPlace,
-              effect: Effect.Freeze,
-            };
+            value.args.push({...depsPlace, effect: Effect.Freeze});
             fn.env.inferredEffectLocations.add(callee.loc);
           }
         } else if (
@@ -344,7 +323,6 @@ export function inferEffectDependencies(fn: HIRFunction): void {
     // Renumber instructions and fix scope ranges
     markInstructionIds(fn.body);
     fixScopeAndIdentifierRanges(fn.body);
-    deadCodeElimination(fn);
 
     fn.env.hasInferredEffect = true;
   }
@@ -430,7 +408,6 @@ function rewriteSplices(
   rewriteBlocks.push(currBlock);
 
   let cursor = 0;
-
   for (const rewrite of splices) {
     while (originalInstrs[cursor].id < rewrite.location) {
       CompilerError.invariant(
@@ -452,7 +429,7 @@ function rewriteSplices(
 
     if (rewrite.kind === 'instr') {
       currBlock.instructions.push(rewrite.value);
-    } else if (rewrite.kind === 'block') {
+    } else {
       const {entry, blocks} = rewrite.value;
       const entryBlock = blocks.get(entry)!;
       // splice in all instructions from the entry block

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

@@ -0,0 +1,206 @@
+/**
+ * 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 {HIRFunction, IdentifierId, Place, ValueKind, ValueReason} from '../HIR';
+import {getOrInsertDefault} from '../Utils/utils';
+import {AliasingEffect} from './AliasingEffects';
+
+/**
+ * This function tracks data flow within an inner function expression in order to
+ * compute a set of data-flow aliasing effects describing data flow between the function's
+ * params, context variables, and return value.
+ *
+ * For example, consider the following function expression:
+ *
+ * ```
+ * (x) => { return [x, y] }
+ * ```
+ *
+ * This function captures both param `x` and context variable `y` into the return value.
+ * Unlike our previous inference which counted this as a mutation of x and y, we want to
+ * build a signature for the function that describes the data flow. We would infer
+ * `Capture x -> return, Capture y -> return` effects for this function.
+ *
+ * This function *also* propagates more ambient-style effects (MutateFrozen, MutateGlobal, Impure, Render)
+ * from instructions within the function up to the function itself.
+ */
+export function inferFunctionExpressionAliasingEffectsSignature(
+  fn: HIRFunction,
+): Array<AliasingEffect> | null {
+  const effects: Array<AliasingEffect> = [];
+
+  /**
+   * Map used to identify tracked variables: params, context vars, return value
+   * This is used to detect mutation/capturing/aliasing of params/context vars
+   */
+  const tracked = new Map<IdentifierId, Place>();
+  tracked.set(fn.returns.identifier.id, fn.returns);
+  for (const operand of [...fn.context, ...fn.params]) {
+    const place = operand.kind === 'Identifier' ? operand : operand.place;
+    tracked.set(place.identifier.id, place);
+  }
+
+  /**
+   * Track capturing/aliasing of context vars and params into each other and into the return.
+   * We don't need to track locals and intermediate values, since we're only concerned with effects
+   * as they relate to arguments visible outside the function.
+   *
+   * For each aliased identifier we track capture/alias/createfrom and then merge this with how
+   * the value is used. Eg capturing an alias => capture. See joinEffects() helper.
+   */
+  type AliasedIdentifier = {
+    kind: AliasingKind;
+    place: Place;
+  };
+  const dataFlow = new Map<IdentifierId, Array<AliasedIdentifier>>();
+
+  /*
+   * Check for aliasing of tracked values. Also joins the effects of how the value is
+   * used (@param kind) with the aliasing type of each value
+   */
+  function lookup(
+    place: Place,
+    kind: AliasedIdentifier['kind'],
+  ): Array<AliasedIdentifier> | null {
+    if (tracked.has(place.identifier.id)) {
+      return [{kind, place}];
+    }
+    return (
+      dataFlow.get(place.identifier.id)?.map(aliased => ({
+        kind: joinEffects(aliased.kind, kind),
+        place: aliased.place,
+      })) ?? null
+    );
+  }
+
+  // todo: fixpoint
+  for (const block of fn.body.blocks.values()) {
+    for (const phi of block.phis) {
+      const operands: Array<AliasedIdentifier> = [];
+      for (const operand of phi.operands.values()) {
+        const inputs = lookup(operand, 'Alias');
+        if (inputs != null) {
+          operands.push(...inputs);
+        }
+      }
+      if (operands.length !== 0) {
+        dataFlow.set(phi.place.identifier.id, operands);
+      }
+    }
+    for (const instr of block.instructions) {
+      if (instr.effects == null) continue;
+      for (const effect of instr.effects) {
+        if (
+          effect.kind === 'Assign' ||
+          effect.kind === 'Capture' ||
+          effect.kind === 'Alias' ||
+          effect.kind === 'CreateFrom'
+        ) {
+          const from = lookup(effect.from, effect.kind);
+          if (from == null) {
+            continue;
+          }
+          const into = lookup(effect.into, 'Alias');
+          if (into == null) {
+            getOrInsertDefault(dataFlow, effect.into.identifier.id, []).push(
+              ...from,
+            );
+          } else {
+            for (const aliased of into) {
+              getOrInsertDefault(
+                dataFlow,
+                aliased.place.identifier.id,
+                [],
+              ).push(...from);
+            }
+          }
+        } else if (
+          effect.kind === 'Create' ||
+          effect.kind === 'CreateFunction'
+        ) {
+          getOrInsertDefault(dataFlow, effect.into.identifier.id, [
+            {kind: 'Alias', place: effect.into},
+          ]);
+        } else if (
+          effect.kind === 'MutateFrozen' ||
+          effect.kind === 'MutateGlobal' ||
+          effect.kind === 'Impure' ||
+          effect.kind === 'Render'
+        ) {
+          effects.push(effect);
+        }
+      }
+    }
+    if (block.terminal.kind === 'return') {
+      const from = lookup(block.terminal.value, 'Alias');
+      if (from != null) {
+        getOrInsertDefault(dataFlow, fn.returns.identifier.id, []).push(
+          ...from,
+        );
+      }
+    }
+  }
+
+  // Create aliasing effects based on observed data flow
+  let hasReturn = false;
+  for (const [into, from] of dataFlow) {
+    const input = tracked.get(into);
+    if (input == null) {
+      continue;
+    }
+    for (const aliased of from) {
+      if (
+        aliased.place.identifier.id === input.identifier.id ||
+        !tracked.has(aliased.place.identifier.id)
+      ) {
+        continue;
+      }
+      const effect = {kind: aliased.kind, from: aliased.place, into: input};
+      effects.push(effect);
+      if (
+        into === fn.returns.identifier.id &&
+        (aliased.kind === 'Assign' || aliased.kind === 'CreateFrom')
+      ) {
+        hasReturn = true;
+      }
+    }
+  }
+  // TODO: more precise return effect inference
+  if (!hasReturn) {
+    effects.unshift({
+      kind: 'Create',
+      into: fn.returns,
+      value:
+        fn.returnType.kind === 'Primitive'
+          ? ValueKind.Primitive
+          : ValueKind.Mutable,
+      reason: ValueReason.KnownReturnSignature,
+    });
+  }
+
+  return effects;
+}
+
+export enum MutationKind {
+  None = 0,
+  Conditional = 1,
+  Definite = 2,
+}
+
+type AliasingKind = 'Alias' | 'Capture' | 'CreateFrom' | 'Assign';
+function joinEffects(
+  effect1: AliasingKind,
+  effect2: AliasingKind,
+): AliasingKind {
+  if (effect1 === 'Capture' || effect2 === 'Capture') {
+    return 'Capture';
+  } else if (effect1 === 'Assign' || effect2 === 'Assign') {
+    return 'Assign';
+  } else {
+    return 'Alias';
+  }
+}

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

@@ -57,6 +57,7 @@ import {
 import {
   printAliasingEffect,
   printAliasingSignature,
+  printFunction,
   printIdentifier,
   printInstruction,
   printInstructionValue,
@@ -193,15 +194,19 @@ export function inferMutationAliasingEffects(
     hoistedContextDeclarations,
   );
 
-  let iterationCount = 0;
+  let count = 0;
   while (queuedStates.size !== 0) {
-    iterationCount++;
-    if (iterationCount > 100) {
-      CompilerError.invariant(false, {
-        reason: `[InferMutationAliasingEffects] Potential infinite loop`,
-        description: `A value, temporary place, or effect was not cached properly`,
-        loc: fn.loc,
-      });
+    count++;
+    if (count > 100) {
+      console.log(
+        'oops infinite loop',
+        fn.id,
+        typeof fn.loc !== 'symbol' ? fn.loc?.filename : null,
+      );
+      if (DEBUG) {
+        console.log(printFunction(fn));
+      }
+      throw new Error('infinite loop');
     }
     for (const [blockId, block] of fn.body.blocks) {
       const incomingState = queuedStates.get(blockId);
@@ -212,6 +217,11 @@ export function inferMutationAliasingEffects(
 
       statesByBlock.set(blockId, incomingState);
       const state = incomingState.clone();
+      if (DEBUG) {
+        console.log('*************');
+        console.log(`bb${block.id}`);
+        console.log('*************');
+      }
       inferBlock(context, state, block);
 
       for (const nextBlockId of eachTerminalSuccessor(block.terminal)) {
@@ -352,11 +362,6 @@ function inferBlock(
   } else if (terminal.kind === 'maybe-throw') {
     const handlerParam = context.catchHandlers.get(terminal.handler);
     if (handlerParam != null) {
-      CompilerError.invariant(state.kind(handlerParam) != null, {
-        reason:
-          'Expected catch binding to be intialized with a DeclareLocal Catch instruction',
-        loc: terminal.loc,
-      });
       const effects: Array<AliasingEffect> = [];
       for (const instr of block.instructions) {
         if (
@@ -471,14 +476,14 @@ function applySignature(
    * Track which values we've already aliased once, so that we can switch to
    * appendAlias() for subsequent aliases into the same value
    */
-  const initialized = new Set<IdentifierId>();
+  const aliased = new Set<IdentifierId>();
 
   if (DEBUG) {
     console.log(printInstruction(instruction));
   }
 
   for (const effect of signature.effects) {
-    applyEffect(context, state, effect, initialized, effects);
+    applyEffect(context, state, effect, aliased, effects);
   }
   if (DEBUG) {
     console.log(
@@ -503,7 +508,7 @@ function applyEffect(
   context: Context,
   state: InferenceState,
   _effect: AliasingEffect,
-  initialized: Set<IdentifierId>,
+  aliased: Set<IdentifierId>,
   effects: Array<AliasingEffect>,
 ): void {
   const effect = context.internEffect(_effect);
@@ -519,13 +524,6 @@ function applyEffect(
       break;
     }
     case 'Create': {
-      CompilerError.invariant(!initialized.has(effect.into.identifier.id), {
-        reason: `Cannot re-initialize variable within an instruction`,
-        description: `Re-initialized ${printPlace(effect.into)} in ${printAliasingEffect(effect)}`,
-        loc: effect.into.loc,
-      });
-      initialized.add(effect.into.identifier.id);
-
       let value = context.effectInstructionValueCache.get(effect);
       if (value == null) {
         value = {
@@ -540,7 +538,6 @@ function applyEffect(
         reason: new Set([effect.reason]),
       });
       state.define(effect.into, value);
-      effects.push(effect);
       break;
     }
     case 'ImmutableCapture': {
@@ -558,13 +555,6 @@ function applyEffect(
       break;
     }
     case 'CreateFrom': {
-      CompilerError.invariant(!initialized.has(effect.into.identifier.id), {
-        reason: `Cannot re-initialize variable within an instruction`,
-        description: `Re-initialized ${printPlace(effect.into)} in ${printAliasingEffect(effect)}`,
-        loc: effect.into.loc,
-      });
-      initialized.add(effect.into.identifier.id);
-
       const fromValue = state.kind(effect.from);
       let value = context.effectInstructionValueCache.get(effect);
       if (value == null) {
@@ -583,21 +573,10 @@ function applyEffect(
       switch (fromValue.kind) {
         case ValueKind.Primitive:
         case ValueKind.Global: {
-          effects.push({
-            kind: 'Create',
-            value: fromValue.kind,
-            into: effect.into,
-            reason: [...fromValue.reason][0] ?? ValueReason.Other,
-          });
+          // no need to track this data flow
           break;
         }
         case ValueKind.Frozen: {
-          effects.push({
-            kind: 'Create',
-            value: fromValue.kind,
-            into: effect.into,
-            reason: [...fromValue.reason][0] ?? ValueReason.Other,
-          });
           applyEffect(
             context,
             state,
@@ -606,7 +585,7 @@ function applyEffect(
               from: effect.from,
               into: effect.into,
             },
-            initialized,
+            aliased,
             effects,
           );
           break;
@@ -618,13 +597,6 @@ function applyEffect(
       break;
     }
     case 'CreateFunction': {
-      CompilerError.invariant(!initialized.has(effect.into.identifier.id), {
-        reason: `Cannot re-initialize variable within an instruction`,
-        description: `Re-initialized ${printPlace(effect.into)} in ${printAliasingEffect(effect)}`,
-        loc: effect.into.loc,
-      });
-      initialized.add(effect.into.identifier.id);
-
       effects.push(effect);
       /**
        * We consider the function mutable if it has any mutable context variables or
@@ -681,7 +653,7 @@ function applyEffect(
             from: capture,
             into: effect.into,
           },
-          initialized,
+          aliased,
           effects,
         );
       }
@@ -689,14 +661,6 @@ function applyEffect(
     }
     case 'Alias':
     case 'Capture': {
-      CompilerError.invariant(
-        effect.kind === 'Capture' || initialized.has(effect.into.identifier.id),
-        {
-          reason: `Expected destination value to already be initialized within this instruction for Alias effect`,
-          description: `Destination ${printPlace(effect.into)} is not initialized in this instruction`,
-          loc: effect.into.loc,
-        },
-      );
       /*
        * Capture describes potential information flow: storing a pointer to one value
        * within another. If the destination is not mutable, or the source value has
@@ -734,7 +698,7 @@ function applyEffect(
               from: effect.from,
               into: effect.into,
             },
-            initialized,
+            aliased,
             effects,
           );
           break;
@@ -750,13 +714,6 @@ function applyEffect(
       break;
     }
     case 'Assign': {
-      CompilerError.invariant(!initialized.has(effect.into.identifier.id), {
-        reason: `Cannot re-initialize variable within an instruction`,
-        description: `Re-initialized ${printPlace(effect.into)} in ${printAliasingEffect(effect)}`,
-        loc: effect.into.loc,
-      });
-      initialized.add(effect.into.identifier.id);
-
       /*
        * Alias represents potential pointer aliasing. If the type is a global,
        * a primitive (copy-on-write semantics) then we can prune the effect
@@ -773,7 +730,7 @@ function applyEffect(
               from: effect.from,
               into: effect.into,
             },
-            initialized,
+            aliased,
             effects,
           );
           let value = context.effectInstructionValueCache.get(effect);
@@ -811,7 +768,12 @@ function applyEffect(
           break;
         }
         default: {
-          state.assign(effect.into, effect.from);
+          if (aliased.has(effect.into.identifier.id)) {
+            state.appendAlias(effect.into, effect.from);
+          } else {
+            aliased.add(effect.into.identifier.id);
+            state.alias(effect.into, effect.from);
+          }
           effects.push(effect);
           break;
         }
@@ -822,8 +784,7 @@ function applyEffect(
       const functionValues = state.values(effect.function);
       if (
         functionValues.length === 1 &&
-        functionValues[0].kind === 'FunctionExpression' &&
-        functionValues[0].loweredFunc.func.aliasingEffects != null
+        functionValues[0].kind === 'FunctionExpression'
       ) {
         /*
          * We're calling a locally declared function, we already know it's effects!
@@ -858,15 +819,18 @@ function applyEffect(
             ),
         );
         if (signatureEffects != null) {
+          if (DEBUG) {
+            console.log('apply function expression effects');
+          }
           applyEffect(
             context,
             state,
             {kind: 'MutateTransitiveConditionally', value: effect.function},
-            initialized,
+            aliased,
             effects,
           );
           for (const signatureEffect of signatureEffects) {
-            applyEffect(context, state, signatureEffect, initialized, effects);
+            applyEffect(context, state, signatureEffect, aliased, effects);
           }
           break;
         }
@@ -890,10 +854,16 @@ function applyEffect(
         );
       }
       if (signatureEffects != null) {
+        if (DEBUG) {
+          console.log('apply aliasing signature effects');
+        }
         for (const signatureEffect of signatureEffects) {
-          applyEffect(context, state, signatureEffect, initialized, effects);
+          applyEffect(context, state, signatureEffect, aliased, effects);
         }
       } else if (effect.signature != null) {
+        if (DEBUG) {
+          console.log('apply legacy signature effects');
+        }
         const legacyEffects = computeEffectsForLegacySignature(
           state,
           effect.signature,
@@ -903,9 +873,12 @@ function applyEffect(
           effect.loc,
         );
         for (const legacyEffect of legacyEffects) {
-          applyEffect(context, state, legacyEffect, initialized, effects);
+          applyEffect(context, state, legacyEffect, aliased, effects);
         }
       } else {
+        if (DEBUG) {
+          console.log('default effects');
+        }
         applyEffect(
           context,
           state,
@@ -915,7 +888,7 @@ function applyEffect(
             value: ValueKind.Mutable,
             reason: ValueReason.Other,
           },
-          initialized,
+          aliased,
           effects,
         );
         /*
@@ -938,21 +911,21 @@ function applyEffect(
                 kind: 'MutateTransitiveConditionally',
                 value: operand,
               },
-              initialized,
+              aliased,
               effects,
             );
           }
           const mutateIterator =
             arg.kind === 'Spread' ? conditionallyMutateIterator(operand) : null;
           if (mutateIterator) {
-            applyEffect(context, state, mutateIterator, initialized, effects);
+            applyEffect(context, state, mutateIterator, aliased, effects);
           }
           applyEffect(
             context,
             state,
             // OK: recording information flow
             {kind: 'Alias', from: operand, into: effect.into},
-            initialized,
+            aliased,
             effects,
           );
           for (const otherArg of [
@@ -980,7 +953,7 @@ function applyEffect(
                 from: operand,
                 into: other,
               },
-              initialized,
+              aliased,
               effects,
             );
           }
@@ -1036,7 +1009,7 @@ function applyEffect(
                   suggestions: null,
                 },
               },
-              initialized,
+              aliased,
               effects,
             );
           }
@@ -1055,7 +1028,7 @@ function applyEffect(
                 suggestions: null,
               },
             },
-            initialized,
+            aliased,
             effects,
           );
         } else {
@@ -1086,7 +1059,7 @@ function applyEffect(
                 suggestions: null,
               },
             },
-            initialized,
+            aliased,
             effects,
           );
         }
@@ -1193,7 +1166,7 @@ class InferenceState {
   }
 
   // Updates the value at @param place to point to the same value as @param value.
-  assign(place: Place, value: Place): void {
+  alias(place: Place, value: Place): void {
     const values = this.#variables.get(value.identifier.id);
     CompilerError.invariant(values != null, {
       reason: `[InferMutationAliasingEffects] Expected value for identifier to be initialized`,
@@ -1271,6 +1244,9 @@ class InferenceState {
       kind: ValueKind.Frozen,
       reason: new Set([reason]),
     });
+    if (DEBUG) {
+      console.log(`freeze value: ${printInstructionValue(value)} ${reason}`);
+    }
     if (
       value.kind === 'FunctionExpression' &&
       (this.env.config.enablePreserveExistingMemoizationGuarantees ||
@@ -2127,6 +2103,8 @@ function computeEffectsForLegacySignature(
         const mutateIterator = conditionallyMutateIterator(place);
         if (mutateIterator != null) {
           effects.push(mutateIterator);
+          // TODO: should we always push to captures?
+          captures.push(place);
         }
         effects.push({
           kind: 'Capture',
@@ -2308,6 +2286,17 @@ function computeEffectsForSignature(
     // Too many args and there is no rest param to hold them
     (args.length > signature.params.length && signature.rest == null)
   ) {
+    if (DEBUG) {
+      if (signature.params.length > args.length) {
+        console.log(
+          `not enough args: ${args.length} args for ${signature.params.length} params`,
+        );
+      } else {
+        console.log(
+          `too many args: ${args.length} args for ${signature.params.length} params, with no rest param`,
+        );
+      }
+    }
     return null;
   }
   // Build substitutions
@@ -2322,6 +2311,9 @@ function computeEffectsForSignature(
       continue;
     } else if (params == null || i >= params.length || arg.kind === 'Spread') {
       if (signature.rest == null) {
+        if (DEBUG) {
+          console.log(`no rest value to hold param`);
+        }
         return null;
       }
       const place = arg.kind === 'Identifier' ? arg : arg.place;
@@ -2429,14 +2421,23 @@ function computeEffectsForSignature(
       case 'Apply': {
         const applyReceiver = substitutions.get(effect.receiver.identifier.id);
         if (applyReceiver == null || applyReceiver.length !== 1) {
+          if (DEBUG) {
+            console.log(`too many substitutions for receiver`);
+          }
           return null;
         }
         const applyFunction = substitutions.get(effect.function.identifier.id);
         if (applyFunction == null || applyFunction.length !== 1) {
+          if (DEBUG) {
+            console.log(`too many substitutions for function`);
+          }
           return null;
         }
         const applyInto = substitutions.get(effect.into.identifier.id);
         if (applyInto == null || applyInto.length !== 1) {
+          if (DEBUG) {
+            console.log(`too many substitutions for into`);
+          }
           return null;
         }
         const applyArgs: Array<Place | SpreadPattern | Hole> = [];
@@ -2446,12 +2447,18 @@ function computeEffectsForSignature(
           } else if (arg.kind === 'Identifier') {
             const applyArg = substitutions.get(arg.identifier.id);
             if (applyArg == null || applyArg.length !== 1) {
+              if (DEBUG) {
+                console.log(`too many substitutions for arg`);
+              }
               return null;
             }
             applyArgs.push(applyArg[0]);
           } else {
             const applyArg = substitutions.get(arg.place.identifier.id);
             if (applyArg == null || applyArg.length !== 1) {
+              if (DEBUG) {
+                console.log(`too many substitutions for arg`);
+              }
               return null;
             }
             applyArgs.push({kind: 'Spread', place: applyArg[0]});

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

@@ -5,6 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import prettyFormat from 'pretty-format';
 import {CompilerError, SourceLocation} from '..';
 import {
   BlockId,
@@ -13,12 +14,8 @@ import {
   Identifier,
   IdentifierId,
   InstructionId,
-  isJsxType,
   makeInstructionId,
-  ValueKind,
-  ValueReason,
   Place,
-  isPrimitiveType,
 } from '../HIR/HIR';
 import {
   eachInstructionLValue,
@@ -26,58 +23,43 @@ import {
   eachTerminalOperand,
 } from '../HIR/visitors';
 import {assertExhaustive, getOrInsertWith} from '../Utils/utils';
-import {Err, Ok, Result} from '../Utils/Result';
-import {AliasingEffect} from './AliasingEffects';
+import {printFunction} from '../HIR';
+import {printIdentifier, printPlace} from '../HIR/PrintHIR';
+import {MutationKind} from './InferFunctionExpressionAliasingEffectsSignature';
+import {Result} from '../Utils/Result';
+
+const DEBUG = false;
+const VERBOSE = false;
 
 /**
- * This pass builds an abstract model of the heap and interprets the effects of the
- * given function in order to determine the following:
- * - The mutable ranges of all identifiers in the function
- * - The externally-visible effects of the function, such as mutations of params and
- *   context-vars, aliasing between params/context-vars/return-value, and impure side
- *   effects.
- * - The legacy `Effect` to store on each Place.
- *
- * This pass builds a data flow graph using the effects, tracking an abstract notion
- * of "when" each effect occurs relative to the others. It then walks each mutation
- * effect against the graph, updating the range of each node that would be reachable
- * at the "time" that the effect occurred.
+ * Infers mutable ranges for all values in the program, using previously inferred
+ * mutation/aliasing effects. This pass builds a data flow graph using the effects,
+ * tracking an abstract notion of "when" each effect occurs relative to the others.
+ * It then walks each mutation effect against the graph, updating the range of each
+ * node that would be reachable at the "time" that the effect occurred.
  *
  * This pass also validates against invalid effects: any function that is reachable
  * by being called, or via a Render effect, is validated against mutating globals
  * or calling impure code.
  *
  * Note that this function also populates the outer function's aliasing effects with
- * any mutations that apply to its params or context variables.
- *
- * ## Example
- * A function expression such as the following:
+ * any mutations that apply to its params or context variables. For example, a
+ * function expression such as the following:
  *
  * ```
  * (x) => { x.y = true }
  * ```
  *
  * Would populate a `Mutate x` aliasing effect on the outer function.
- *
- * ## Returned Function Effects
- *
- * The function returns (if successful) a list of externally-visible effects.
- * This is determined by simulating a conditional, transitive mutation against
- * each param, context variable, and return value in turn, and seeing which other
- * such values are affected. If they're affected, they must be captured, so we
- * record a Capture.
- *
- * The only tricky bit is the return value, which could _alias_ (or even assign)
- * one or more of the params/context-vars rather than just capturing. So we have
- * to do a bit more tracking for returns.
  */
 export function inferMutationAliasingRanges(
   fn: HIRFunction,
   {isFunctionExpression}: {isFunctionExpression: boolean},
-): Result<Array<AliasingEffect>, CompilerError> {
-  // The set of externally-visible effects
-  const functionEffects: Array<AliasingEffect> = [];
-
+): Result<void, CompilerError> {
+  if (VERBOSE) {
+    console.log();
+    console.log(printFunction(fn));
+  }
   /**
    * Part 1: Infer mutable ranges for values. We build an abstract model of
    * values, the alias/capture edges between them, and the set of mutations.
@@ -133,6 +115,20 @@ export function inferMutationAliasingRanges(
     seenBlocks.add(block.id);
 
     for (const instr of block.instructions) {
+      if (
+        instr.value.kind === 'FunctionExpression' ||
+        instr.value.kind === 'ObjectMethod'
+      ) {
+        state.create(instr.lvalue, {
+          kind: 'Function',
+          function: instr.value.loweredFunc.func,
+        });
+      } else {
+        for (const lvalue of eachInstructionLValue(instr)) {
+          state.create(lvalue, {kind: 'Object'});
+        }
+      }
+
       if (instr.effects == null) continue;
       for (const effect of instr.effects) {
         if (effect.kind === 'Create') {
@@ -145,15 +141,6 @@ export function inferMutationAliasingRanges(
         } else if (effect.kind === 'CreateFrom') {
           state.createFrom(index++, effect.from, effect.into);
         } else if (effect.kind === 'Assign') {
-          /**
-           * TODO: Invariant that the node is not initialized yet
-           *
-           * InferFunctionExpressionAliasingEffectSignatures currently infers
-           * Assign effects in some places that should be Alias, leading to
-           * Assign effects that reinitialize a value. The end result appears to
-           * be fine, but we should fix that inference pass so that we add the
-           * invariant here.
-           */
           if (!state.nodes.has(effect.into.identifier)) {
             state.create(effect.into, {kind: 'Object'});
           }
@@ -196,10 +183,8 @@ export function inferMutationAliasingRanges(
           effect.kind === 'Impure'
         ) {
           errors.push(effect.error);
-          functionEffects.push(effect);
         } else if (effect.kind === 'Render') {
           renders.push({index: index++, place: effect.place});
-          functionEffects.push(effect);
         }
       }
     }
@@ -231,6 +216,10 @@ export function inferMutationAliasingRanges(
     }
   }
 
+  if (VERBOSE) {
+    console.log(state.debug());
+    console.log(pretty(mutations));
+  }
   for (const mutation of mutations) {
     state.mutate(
       mutation.index,
@@ -245,6 +234,10 @@ export function inferMutationAliasingRanges(
   for (const render of renders) {
     state.render(render.index, render.place.identifier, errors);
   }
+  if (DEBUG) {
+    console.log(pretty([...state.nodes.keys()]));
+  }
+  fn.aliasingEffects ??= [];
   for (const param of [...fn.context, ...fn.params]) {
     const place = param.kind === 'Identifier' ? param : param.place;
     const node = state.nodes.get(place.identifier);
@@ -255,13 +248,13 @@ export function inferMutationAliasingRanges(
     if (node.local != null) {
       if (node.local.kind === MutationKind.Conditional) {
         mutated = true;
-        functionEffects.push({
+        fn.aliasingEffects.push({
           kind: 'MutateConditionally',
           value: {...place, loc: node.local.loc},
         });
       } else if (node.local.kind === MutationKind.Definite) {
         mutated = true;
-        functionEffects.push({
+        fn.aliasingEffects.push({
           kind: 'Mutate',
           value: {...place, loc: node.local.loc},
         });
@@ -270,13 +263,13 @@ export function inferMutationAliasingRanges(
     if (node.transitive != null) {
       if (node.transitive.kind === MutationKind.Conditional) {
         mutated = true;
-        functionEffects.push({
+        fn.aliasingEffects.push({
           kind: 'MutateTransitiveConditionally',
           value: {...place, loc: node.transitive.loc},
         });
       } else if (node.transitive.kind === MutationKind.Definite) {
         mutated = true;
-        functionEffects.push({
+        fn.aliasingEffects.push({
           kind: 'MutateTransitive',
           value: {...place, loc: node.transitive.loc},
         });
@@ -465,82 +458,10 @@ export function inferMutationAliasingRanges(
     }
   }
 
-  /**
-   * Part 3
-   * Finish populating the externally visible effects. Above we bubble-up the side effects
-   * (MutateFrozen/MutableGlobal/Impure/Render) as well as mutations of context variables.
-   * Here we populate an effect to create the return value as well as populating alias/capture
-   * effects for how data flows between the params, context vars, and return.
-   */
-  const returns = fn.returns.identifier;
-  functionEffects.push({
-    kind: 'Create',
-    into: fn.returns,
-    value: isPrimitiveType(returns)
-      ? ValueKind.Primitive
-      : isJsxType(returns.type)
-        ? ValueKind.Frozen
-        : ValueKind.Mutable,
-    reason: ValueReason.KnownReturnSignature,
-  });
-  /**
-   * Determine precise data-flow effects by simulating transitive mutations of the params/
-   * captures and seeing what other params/context variables are affected. Anything that
-   * would be transitively mutated needs a capture relationship.
-   */
-  const tracked: Array<Place> = [];
-  const ignoredErrors = new CompilerError();
-  for (const param of [...fn.params, ...fn.context, fn.returns]) {
-    const place = param.kind === 'Identifier' ? param : param.place;
-    tracked.push(place);
+  if (VERBOSE) {
+    console.log(printFunction(fn));
   }
-  for (const into of tracked) {
-    const mutationIndex = index++;
-    state.mutate(
-      mutationIndex,
-      into.identifier,
-      null,
-      true,
-      MutationKind.Conditional,
-      into.loc,
-      ignoredErrors,
-    );
-    for (const from of tracked) {
-      if (
-        from.identifier.id === into.identifier.id ||
-        from.identifier.id === fn.returns.identifier.id
-      ) {
-        continue;
-      }
-      const fromNode = state.nodes.get(from.identifier);
-      CompilerError.invariant(fromNode != null, {
-        reason: `Expected a node to exist for all parameters and context variables`,
-        loc: into.loc,
-      });
-      if (fromNode.lastMutated === mutationIndex) {
-        if (into.identifier.id === fn.returns.identifier.id) {
-          // The return value could be any of the params/context variables
-          functionEffects.push({
-            kind: 'Alias',
-            from,
-            into,
-          });
-        } else {
-          // Otherwise params/context-vars can only capture each other
-          functionEffects.push({
-            kind: 'Capture',
-            from,
-            into,
-          });
-        }
-      }
-    }
-  }
-
-  if (errors.hasErrors() && !isFunctionExpression) {
-    return Err(errors);
-  }
-  return Ok(functionEffects);
+  return errors.asResult();
 }
 
 function appendFunctionErrors(errors: CompilerError, fn: HIRFunction): void {
@@ -556,12 +477,6 @@ function appendFunctionErrors(errors: CompilerError, fn: HIRFunction): void {
   }
 }
 
-export enum MutationKind {
-  None = 0,
-  Conditional = 1,
-  Definite = 2,
-}
-
 type Node = {
   id: Identifier;
   createdFrom: Map<Identifier, number>;
@@ -570,7 +485,6 @@ type Node = {
   edges: Array<{index: number; node: Identifier; kind: 'capture' | 'alias'}>;
   transitive: {kind: MutationKind; loc: SourceLocation} | null;
   local: {kind: MutationKind; loc: SourceLocation} | null;
-  lastMutated: number;
   value:
     | {kind: 'Object'}
     | {kind: 'Phi'}
@@ -588,7 +502,6 @@ class AliasingState {
       edges: [],
       transitive: null,
       local: null,
-      lastMutated: 0,
       value,
     });
   }
@@ -598,6 +511,11 @@ class AliasingState {
     const fromNode = this.nodes.get(from.identifier);
     const toNode = this.nodes.get(into.identifier);
     if (fromNode == null || toNode == null) {
+      if (VERBOSE) {
+        console.log(
+          `skip: createFrom ${printPlace(from)}${!!fromNode} -> ${printPlace(into)}${!!toNode}`,
+        );
+      }
       return;
     }
     fromNode.edges.push({index, node: into.identifier, kind: 'alias'});
@@ -610,6 +528,11 @@ class AliasingState {
     const fromNode = this.nodes.get(from.identifier);
     const toNode = this.nodes.get(into.identifier);
     if (fromNode == null || toNode == null) {
+      if (VERBOSE) {
+        console.log(
+          `skip: capture ${printPlace(from)}${!!fromNode} -> ${printPlace(into)}${!!toNode}`,
+        );
+      }
       return;
     }
     fromNode.edges.push({index, node: into.identifier, kind: 'capture'});
@@ -622,6 +545,11 @@ class AliasingState {
     const fromNode = this.nodes.get(from.identifier);
     const toNode = this.nodes.get(into.identifier);
     if (fromNode == null || toNode == null) {
+      if (VERBOSE) {
+        console.log(
+          `skip: assign ${printPlace(from)}${!!fromNode} -> ${printPlace(into)}${!!toNode}`,
+        );
+      }
       return;
     }
     fromNode.edges.push({index, node: into.identifier, kind: 'alias'});
@@ -670,13 +598,17 @@ class AliasingState {
   mutate(
     index: number,
     start: Identifier,
-    // Null is used for simulated mutations
-    end: InstructionId | null,
+    end: InstructionId,
     transitive: boolean,
     kind: MutationKind,
     loc: SourceLocation,
     errors: CompilerError,
   ): void {
+    if (DEBUG) {
+      console.log(
+        `mutate ix=${index} start=$${start.id} end=[${end}]${transitive ? ' transitive' : ''} kind=${kind}`,
+      );
+    }
     const seen = new Set<Identifier>();
     const queue: Array<{
       place: Identifier;
@@ -691,14 +623,21 @@ class AliasingState {
       seen.add(current);
       const node = this.nodes.get(current);
       if (node == null) {
+        if (DEBUG) {
+          console.log(
+            `no node! ${printIdentifier(start)} for identifier ${printIdentifier(current)}`,
+          );
+        }
         continue;
       }
-      node.lastMutated = Math.max(node.lastMutated, index);
-      if (end != null) {
-        node.id.mutableRange.end = makeInstructionId(
-          Math.max(node.id.mutableRange.end, end),
+      if (DEBUG) {
+        console.log(
+          `  mutate $${node.id.id} transitive=${transitive} direction=${direction}`,
         );
       }
+      node.id.mutableRange.end = makeInstructionId(
+        Math.max(node.id.mutableRange.end, end),
+      );
       if (
         node.value.kind === 'Function' &&
         node.transitive == null &&
@@ -762,5 +701,37 @@ class AliasingState {
         }
       }
     }
+    if (DEBUG) {
+      const nodes = new Map();
+      for (const id of seen) {
+        const node = this.nodes.get(id);
+        nodes.set(id.id, node);
+      }
+      console.log(pretty(nodes));
+    }
+  }
+
+  debug(): string {
+    return pretty(this.nodes);
   }
 }
+
+export function pretty(v: any): string {
+  return prettyFormat(v, {
+    plugins: [
+      {
+        test: v =>
+          v !== null && typeof v === 'object' && v.kind === 'Identifier',
+        serialize: v => printPlace(v),
+      },
+      {
+        test: v =>
+          v !== null &&
+          typeof v === 'object' &&
+          typeof v.declarationId === 'number',
+        serialize: v =>
+          `${printIdentifier(v)}:${v.mutableRange.start}:${v.mutableRange.end}`,
+      },
+    ],
+  });
+}

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

@@ -11,7 +11,6 @@ import {
   Environment,
   FunctionExpression,
   GeneratedSource,
-  GotoTerminal,
   GotoVariant,
   HIRFunction,
   IdentifierId,
@@ -20,7 +19,6 @@ import {
   Place,
   isStatementBlockKind,
   makeInstructionId,
-  mergeConsecutiveBlocks,
   promoteTemporary,
   reversePostorderBlocks,
 } from '../HIR';
@@ -75,10 +73,6 @@ import {retainWhere} from '../Utils/utils';
  * - All return statements in the original function expression are replaced with a
  *    StoreLocal to the temporary we allocated before plus a Goto to the fallthrough
  *    block (code following the CallExpression).
- *
- * Note that if the inliined function has only one return, we avoid the labeled block
- * and fully inline the code. The original return is replaced with an assignmen to the
- * IIFE's call expression lvalue.
  */
 export function inlineImmediatelyInvokedFunctionExpressions(
   fn: HIRFunction,
@@ -152,75 +146,37 @@ export function inlineImmediatelyInvokedFunctionExpressions(
              */
             block.instructions.length = ii;
 
-            if (hasSingleExitReturnTerminal(body.loweredFunc.func)) {
-              block.terminal = {
-                kind: 'goto',
-                block: body.loweredFunc.func.body.entry,
-                id: block.terminal.id,
-                loc: block.terminal.loc,
-                variant: GotoVariant.Break,
-              } as GotoTerminal;
-              for (const block of body.loweredFunc.func.body.blocks.values()) {
-                if (block.terminal.kind === 'return') {
-                  block.instructions.push({
-                    id: makeInstructionId(0),
-                    loc: block.terminal.loc,
-                    lvalue: instr.lvalue,
-                    value: {
-                      kind: 'LoadLocal',
-                      loc: block.terminal.loc,
-                      place: block.terminal.value,
-                    },
-                    effects: null,
-                  });
-                  block.terminal = {
-                    kind: 'goto',
-                    block: continuationBlockId,
-                    id: block.terminal.id,
-                    loc: block.terminal.loc,
-                    variant: GotoVariant.Break,
-                  } as GotoTerminal;
-                }
-              }
-              for (const [id, block] of body.loweredFunc.func.body.blocks) {
-                block.preds.clear();
-                fn.body.blocks.set(id, block);
-              }
-            } else {
-              /*
-               * To account for multiple returns within the lambda, we treat the lambda
-               * as if it were a single labeled statement, and replace all returns with gotos
-               * to the label fallthrough.
-               */
-              const newTerminal: LabelTerminal = {
-                block: body.loweredFunc.func.body.entry,
-                id: makeInstructionId(0),
-                kind: 'label',
-                fallthrough: continuationBlockId,
-                loc: block.terminal.loc,
-              };
-              block.terminal = newTerminal;
+            /*
+             * To account for complex control flow within the lambda, we treat the lambda
+             * as if it were a single labeled statement, and replace all returns with gotos
+             * to the label fallthrough.
+             */
+            const newTerminal: LabelTerminal = {
+              block: body.loweredFunc.func.body.entry,
+              id: makeInstructionId(0),
+              kind: 'label',
+              fallthrough: continuationBlockId,
+              loc: block.terminal.loc,
+            };
+            block.terminal = newTerminal;
 
-              // We store the result in the IIFE temporary
-              const result = instr.lvalue;
+            // We store the result in the IIFE temporary
+            const result = instr.lvalue;
 
-              // Declare the IIFE temporary
-              declareTemporary(fn.env, block, result);
+            // Declare the IIFE temporary
+            declareTemporary(fn.env, block, result);
 
-              // Promote the temporary with a name as we require this to persist
-              if (result.identifier.name == null) {
-                promoteTemporary(result.identifier);
-              }
+            // Promote the temporary with a name as we require this to persist
+            promoteTemporary(result.identifier);
 
-              /*
-               * Rewrite blocks from the lambda to replace any `return` with a
-               * store to the result and `goto` the continuation block
-               */
-              for (const [id, block] of body.loweredFunc.func.body.blocks) {
-                block.preds.clear();
-                rewriteBlock(fn.env, block, continuationBlockId, result);
-                fn.body.blocks.set(id, block);
-              }
+            /*
+             * Rewrite blocks from the lambda to replace any `return` with a
+             * store to the result and `goto` the continuation block
+             */
+            for (const [id, block] of body.loweredFunc.func.body.blocks) {
+              block.preds.clear();
+              rewriteBlock(fn.env, block, continuationBlockId, result);
+              fn.body.blocks.set(id, block);
             }
 
             /*
@@ -243,7 +199,7 @@ export function inlineImmediatelyInvokedFunctionExpressions(
 
   if (inlinedFunctions.size !== 0) {
     // Remove instructions that define lambdas which we inlined
-    for (const block of fn.body.blocks.values()) {
+    for (const [, block] of fn.body.blocks) {
       retainWhere(
         block.instructions,
         instr => !inlinedFunctions.has(instr.lvalue.identifier.id),
@@ -257,25 +213,9 @@ export function inlineImmediatelyInvokedFunctionExpressions(
     reversePostorderBlocks(fn.body);
     markInstructionIds(fn.body);
     markPredecessors(fn.body);
-    mergeConsecutiveBlocks(fn);
   }
 }
 
-/**
- * Returns true if the function has a single exit terminal (throw/return) which is a return
- */
-function hasSingleExitReturnTerminal(fn: HIRFunction): boolean {
-  let hasReturn = false;
-  let exitCount = 0;
-  for (const [, block] of fn.body.blocks) {
-    if (block.terminal.kind === 'return' || block.terminal.kind === 'throw') {
-      hasReturn ||= block.terminal.kind === 'return';
-      exitCount++;
-    }
-  }
-  return exitCount === 1 && hasReturn;
-}
-
 /*
  * Rewrites the block so that all `return` terminals are replaced:
  * * Add a StoreLocal <returnValue> = <terminal.value>

compiler/packages/babel-plugin-react-compiler/src/Inference/MUTABILITY_ALIASING_MODEL.md

@@ -514,9 +514,9 @@ Intuition: these effects are inverses of each other (capturing into an object, e
 Capture then CreatFrom is equivalent to Alias: we have to assume that the result _is_ the original value and that a local mutation of the result could mutate the original.
 
 ```js
-const b = [a]; // capture
-const c = b[0]; // createfrom
-mutate(c); // this clearly can mutate a, so the result must be one of Assign/Alias/CreateFrom 
+const y = [x]; // capture
+const z = y[0]; // createfrom
+mutate(z); // this clearly can mutate x, so the result must be one of Assign/Alias/CreateFrom 
 ```
 
 We use Alias as the return type because the mutability kind of the result is not derived from the source value (there's a fresh object in between due to the capture), so the full set of effects in practice would be a Create+Alias.
@@ -528,17 +528,17 @@ CreateFrom c <- b
 Alias c <- a
 ```
 
-Meanwhile the opposite direction preserves the capture, because the result is not the same as the source:
+Meanwhile the opposite direction preservers the capture, because the result is not the same as the source:
 
 ```js
-const b = a[0]; // createfrom
-const c = [b]; // capture
-mutate(c); // does not mutate a, so the result must be Capture
+const y = x[0]; // createfrom
+const z = [y]; // capture
+mutate(z); // does not mutate x, so the result must be Capture
 ```
 
 ```
-CreateFrom b <- a
-Capture c <- b
+Capture b <- a
+CreateFrom c <- b
 =>
-Capture c <- a
+Capture b <- a
 ```

compiler/packages/babel-plugin-react-compiler/src/Optimization/LowerContextAccess.ts

@@ -25,6 +25,7 @@ import {
   makeBlockId,
   makeInstructionId,
   makePropertyLiteral,
+  makeType,
   markInstructionIds,
   promoteTemporary,
   reversePostorderBlocks,
@@ -252,6 +253,7 @@ function emitSelectorFn(env: Environment, keys: Array<string>): Instruction {
     env,
     params: [obj],
     returnTypeAnnotation: null,
+    returnType: makeType(),
     returns: createTemporaryPlace(env, GeneratedSource),
     context: [],
     effects: null,

compiler/packages/babel-plugin-react-compiler/src/Optimization/OutlineJsx.ts

@@ -21,6 +21,7 @@ import {
   makeBlockId,
   makeIdentifierName,
   makeInstructionId,
+  makeType,
   ObjectProperty,
   Place,
   promoteTemporary,
@@ -367,6 +368,7 @@ function emitOutlinedFn(
     env,
     params: [propsObj],
     returnTypeAnnotation: null,
+    returnType: makeType(),
     returns: createTemporaryPlace(env, GeneratedSource),
     context: [],
     effects: null,

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

@@ -349,9 +349,11 @@ function codegenReactiveFunction(
   fn: ReactiveFunction,
 ): Result<CodegenFunction, CompilerError> {
   for (const param of fn.params) {
-    const place = param.kind === 'Identifier' ? param : param.place;
-    cx.temp.set(place.identifier.declarationId, null);
-    cx.declare(place.identifier);
+    if (param.kind === 'Identifier') {
+      cx.temp.set(param.identifier.declarationId, null);
+    } else {
+      cx.temp.set(param.place.identifier.declarationId, null);
+    }
   }
 
   const params = fn.params.map(param => convertParameter(param));
@@ -1181,7 +1183,7 @@ function codegenTerminal(
               ? codegenPlaceToExpression(cx, case_.test)
               : null;
           const block = codegenBlock(cx, case_.block!);
-          return t.switchCase(test, block.body.length === 0 ? [] : [block]);
+          return t.switchCase(test, [block]);
         }),
       );
     }

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

@@ -79,10 +79,6 @@ export function extractScopeDeclarationsFromDestructuring(
   fn: ReactiveFunction,
 ): void {
   const state = new State(fn.env);
-  for (const param of fn.params) {
-    const place = param.kind === 'Identifier' ? param : param.place;
-    state.declared.add(place.identifier.declarationId);
-  }
   visitReactiveFunction(fn, new Visitor(), state);
 }
 

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

@@ -829,14 +829,12 @@ class CollectDependenciesVisitor extends ReactiveFunctionVisitor<
         };
       }
       case 'UnsupportedNode': {
-        const lvalues = [];
-        if (lvalue !== null) {
-          lvalues.push({place: lvalue, level: MemoizationLevel.Never});
-        }
-        return {
-          lvalues,
-          rvalues: [],
-        };
+        CompilerError.invariant(false, {
+          reason: `Unexpected unsupported node`,
+          description: null,
+          loc: value.loc,
+          suggestions: null,
+        });
       }
       default: {
         assertExhaustive(
@@ -1066,29 +1064,12 @@ class PruneScopesTransform extends ReactiveFunctionTransform<
 
     const value = instruction.value;
     if (value.kind === 'StoreLocal' && value.lvalue.kind === 'Reassign') {
-      // Complex cases of useMemo inlining result in a temporary that is reassigned
       const ids = getOrInsertDefault(
         this.reassignments,
         value.lvalue.place.identifier.declarationId,
         new Set(),
       );
       ids.add(value.value.identifier);
-    } else if (
-      value.kind === 'LoadLocal' &&
-      value.place.identifier.scope != null &&
-      instruction.lvalue != null &&
-      instruction.lvalue.identifier.scope == null
-    ) {
-      /*
-       * Simpler cases result in a direct assignment to the original lvalue, with a
-       * LoadLocal
-       */
-      const ids = getOrInsertDefault(
-        this.reassignments,
-        instruction.lvalue.identifier.declarationId,
-        new Set(),
-      );
-      ids.add(value.place.identifier);
     } else if (value.kind === 'FinishMemoize') {
       let decls;
       if (value.decl.identifier.scope == null) {

compiler/packages/babel-plugin-react-compiler/src/TypeInference/InferTypes.ts

@@ -90,8 +90,7 @@ function apply(func: HIRFunction, unifier: Unifier): void {
       }
     }
   }
-  const returns = func.returns.identifier;
-  returns.type = unifier.get(returns.type);
+  func.returnType = unifier.get(func.returnType);
 }
 
 type TypeEquation = {
@@ -144,12 +143,12 @@ function* generate(
     }
   }
   if (returnTypes.length > 1) {
-    yield equation(func.returns.identifier.type, {
+    yield equation(func.returnType, {
       kind: 'Phi',
       operands: returnTypes,
     });
   } else if (returnTypes.length === 1) {
-    yield equation(func.returns.identifier.type, returnTypes[0]!);
+    yield equation(func.returnType, returnTypes[0]!);
   }
 }
 
@@ -408,7 +407,7 @@ function* generateInstructionTypes(
       yield equation(left, {
         kind: 'Function',
         shapeId: BuiltInFunctionId,
-        return: value.loweredFunc.func.returns.identifier.type,
+        return: value.loweredFunc.func.returnType,
         isConstructor: false,
       });
       break;

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

@@ -75,21 +75,21 @@ const testComplexConfigDefaults: PartialEnvironmentConfig = {
         source: 'react',
         importSpecifierName: 'useEffect',
       },
-      autodepsIndex: 1,
+      numRequiredArgs: 1,
     },
     {
       function: {
         source: 'shared-runtime',
         importSpecifierName: 'useSpecialEffect',
       },
-      autodepsIndex: 2,
+      numRequiredArgs: 2,
     },
     {
       function: {
         source: 'useEffectWrapper',
         importSpecifierName: 'default',
       },
-      autodepsIndex: 1,
+      numRequiredArgs: 1,
     },
   ],
 };

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

@@ -11,22 +11,20 @@ import {
   IdentifierId,
   isSetStateType,
   isUseEffectHookType,
-  isUseInsertionEffectHookType,
-  isUseLayoutEffectHookType,
   Place,
 } from '../HIR';
 import {eachInstructionValueOperand} from '../HIR/visitors';
 import {Result} from '../Utils/Result';
 
 /**
- * Validates against calling setState in the body of an effect (useEffect and friends),
+ * Validates against calling setState in the body of a *passive* effect (useEffect),
  * while allowing calling setState in callbacks scheduled by the effect.
  *
  * Calling setState during execution of a useEffect triggers a re-render, which is
  * often bad for performance and frequently has more efficient and straightforward
  * alternatives. See https://react.dev/learn/you-might-not-need-an-effect for examples.
  */
-export function validateNoSetStateInEffects(
+export function validateNoSetStateInPassiveEffects(
   fn: HIRFunction,
 ): Result<void, CompilerError> {
   const setStateFunctions: Map<IdentifierId, Place> = new Map();
@@ -81,11 +79,7 @@ export function validateNoSetStateInEffects(
             instr.value.kind === 'MethodCall'
               ? instr.value.receiver
               : instr.value.callee;
-          if (
-            isUseEffectHookType(callee.identifier) ||
-            isUseLayoutEffectHookType(callee.identifier) ||
-            isUseInsertionEffectHookType(callee.identifier)
-          ) {
+          if (isUseEffectHookType(callee.identifier)) {
             const arg = instr.value.args[0];
             if (arg !== undefined && arg.kind === 'Identifier') {
               const setState = setStateFunctions.get(arg.identifier.id);

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

@@ -445,13 +445,11 @@ class Visitor extends ReactiveFunctionVisitor<VisitorState> {
      */
     this.recordTemporaries(instruction, state);
     const value = instruction.value;
-    // Track reassignments from inlining of manual memo
     if (
       value.kind === 'StoreLocal' &&
       value.lvalue.kind === 'Reassign' &&
       state.manualMemoState != null
     ) {
-      // Complex cases of inlining end up with a temporary that is reassigned
       const ids = getOrInsertDefault(
         state.manualMemoState.reassignments,
         value.lvalue.place.identifier.declarationId,
@@ -459,21 +457,6 @@ class Visitor extends ReactiveFunctionVisitor<VisitorState> {
       );
       ids.add(value.value.identifier);
     }
-    if (
-      value.kind === 'LoadLocal' &&
-      value.place.identifier.scope != null &&
-      instruction.lvalue != null &&
-      instruction.lvalue.identifier.scope == null &&
-      state.manualMemoState != null
-    ) {
-      // Simpler cases of inlining assign to the original IIFE lvalue
-      const ids = getOrInsertDefault(
-        state.manualMemoState.reassignments,
-        instruction.lvalue.identifier.declarationId,
-        new Set(),
-      );
-      ids.add(value.place.identifier);
-    }
     if (value.kind === 'StartMemoize') {
       let depsFromSource: Array<ManualMemoDependency> | null = null;
       if (value.deps != null) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/envConfig-test.ts

@@ -20,7 +20,7 @@ describe('parseConfigPragma()', () => {
         validateHooksUsage: 1,
       } as any);
     }).toThrowErrorMatchingInlineSnapshot(
-      `"Error: Could not validate environment config. Update React Compiler config to fix the error. Validation error: Expected boolean, received number at "validateHooksUsage"."`,
+      `"InvalidConfig: Could not validate environment config. Update React Compiler config to fix the error. Validation error: Expected boolean, received number at "validateHooksUsage""`,
     );
   });
 
@@ -33,12 +33,12 @@ describe('parseConfigPragma()', () => {
               source: 'react',
               importSpecifierName: 'useEffect',
             },
-            autodepsIndex: 0,
+            numRequiredArgs: 0,
           },
         ],
       } as any);
     }).toThrowErrorMatchingInlineSnapshot(
-      `"Error: Could not validate environment config. Update React Compiler config to fix the error. Validation error: autodepsIndex must be > 0 at "inferEffectDependencies[0].autodepsIndex"."`,
+      `"InvalidConfig: Could not validate environment config. Update React Compiler config to fix the error. Validation error: numRequiredArgs must be > 0 at "inferEffectDependencies[0].numRequiredArgs""`,
     );
   });
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/align-scopes-iife-return-modified-later-logical.expect.md

@@ -26,16 +26,20 @@ import { c as _c } from "react/compiler-runtime";
 import { getNull } from "shared-runtime";
 
 function Component(props) {
-  const $ = _c(2);
+  const $ = _c(3);
+  let t0;
   let items;
   if ($[0] !== props.a) {
-    items = getNull() ?? [];
+    t0 = getNull() ?? [];
+    items = t0;
 
     items.push(props.a);
     $[0] = props.a;
     $[1] = items;
+    $[2] = t0;
   } else {
     items = $[1];
+    t0 = $[2];
   }
   return items;
 }

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-modify-global-in-callback-jsx.expect.md

@@ -52,13 +52,15 @@ function Component(t0) {
   }
   const onClick = t1;
   let t2;
+  let t3;
   if ($[2] !== onClick) {
-    t2 = <div onClick={onClick}>{someGlobal.value}</div>;
+    t3 = <div onClick={onClick}>{someGlobal.value}</div>;
     $[2] = onClick;
-    $[3] = t2;
+    $[3] = t3;
   } else {
-    t2 = $[3];
+    t3 = $[3];
   }
+  t2 = t3;
   return t2;
 }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/babel-existing-react-import.expect.md

@@ -30,46 +30,50 @@ function Component(props) {
   const $ = _c(4);
   const [x] = useState(0);
   let t0;
-  if ($[0] !== x) {
-    t0 = calculateExpensiveNumber(x);
-    $[0] = x;
-    $[1] = t0;
-  } else {
-    t0 = $[1];
-  }
-  const expensiveNumber = t0;
   let t1;
-  if ($[2] !== expensiveNumber) {
-    t1 = <div>{expensiveNumber}</div>;
-    $[2] = expensiveNumber;
-    $[3] = t1;
+  if ($[0] !== x) {
+    t1 = calculateExpensiveNumber(x);
+    $[0] = x;
+    $[1] = t1;
   } else {
-    t1 = $[3];
+    t1 = $[1];
   }
-  return t1;
+  t0 = t1;
+  const expensiveNumber = t0;
+  let t2;
+  if ($[2] !== expensiveNumber) {
+    t2 = <div>{expensiveNumber}</div>;
+    $[2] = expensiveNumber;
+    $[3] = t2;
+  } else {
+    t2 = $[3];
+  }
+  return t2;
 }
 
 function Component2(props) {
   const $ = _c(4);
   const [x] = useState(0);
   let t0;
-  if ($[0] !== x) {
-    t0 = calculateExpensiveNumber(x);
-    $[0] = x;
-    $[1] = t0;
-  } else {
-    t0 = $[1];
-  }
-  const expensiveNumber = t0;
   let t1;
-  if ($[2] !== expensiveNumber) {
-    t1 = <div>{expensiveNumber}</div>;
-    $[2] = expensiveNumber;
-    $[3] = t1;
+  if ($[0] !== x) {
+    t1 = calculateExpensiveNumber(x);
+    $[0] = x;
+    $[1] = t1;
   } else {
-    t1 = $[3];
+    t1 = $[1];
   }
-  return t1;
+  t0 = t1;
+  const expensiveNumber = t0;
+  let t2;
+  if ($[2] !== expensiveNumber) {
+    t2 = <div>{expensiveNumber}</div>;
+    $[2] = expensiveNumber;
+    $[3] = t2;
+  } else {
+    t2 = $[3];
+  }
+  return t2;
 }
 
 ```

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/babel-existing-react-kitchensink-import.expect.md

@@ -32,46 +32,50 @@ function Component(props) {
   const $ = _c(4);
   const [x] = useState(0);
   let t0;
-  if ($[0] !== x) {
-    t0 = calculateExpensiveNumber(x);
-    $[0] = x;
-    $[1] = t0;
-  } else {
-    t0 = $[1];
-  }
-  const expensiveNumber = t0;
   let t1;
-  if ($[2] !== expensiveNumber) {
-    t1 = <div>{expensiveNumber}</div>;
-    $[2] = expensiveNumber;
-    $[3] = t1;
+  if ($[0] !== x) {
+    t1 = calculateExpensiveNumber(x);
+    $[0] = x;
+    $[1] = t1;
   } else {
-    t1 = $[3];
+    t1 = $[1];
   }
-  return t1;
+  t0 = t1;
+  const expensiveNumber = t0;
+  let t2;
+  if ($[2] !== expensiveNumber) {
+    t2 = <div>{expensiveNumber}</div>;
+    $[2] = expensiveNumber;
+    $[3] = t2;
+  } else {
+    t2 = $[3];
+  }
+  return t2;
 }
 
 function Component2(props) {
   const $ = _c(4);
   const [x] = useState(0);
   let t0;
-  if ($[0] !== x) {
-    t0 = calculateExpensiveNumber(x);
-    $[0] = x;
-    $[1] = t0;
-  } else {
-    t0 = $[1];
-  }
-  const expensiveNumber = t0;
   let t1;
-  if ($[2] !== expensiveNumber) {
-    t1 = <div>{expensiveNumber}</div>;
-    $[2] = expensiveNumber;
-    $[3] = t1;
+  if ($[0] !== x) {
+    t1 = calculateExpensiveNumber(x);
+    $[0] = x;
+    $[1] = t1;
   } else {
-    t1 = $[3];
+    t1 = $[1];
   }
-  return t1;
+  t0 = t1;
+  const expensiveNumber = t0;
+  let t2;
+  if ($[2] !== expensiveNumber) {
+    t2 = <div>{expensiveNumber}</div>;
+    $[2] = expensiveNumber;
+    $[3] = t2;
+  } else {
+    t2 = $[3];
+  }
+  return t2;
 }
 
 ```

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/babel-existing-react-namespace-import.expect.md

@@ -30,23 +30,25 @@ function Component(props) {
   const $ = _c(4);
   const [x] = React.useState(0);
   let t0;
-  if ($[0] !== x) {
-    t0 = calculateExpensiveNumber(x);
-    $[0] = x;
-    $[1] = t0;
-  } else {
-    t0 = $[1];
-  }
-  const expensiveNumber = t0;
   let t1;
-  if ($[2] !== expensiveNumber) {
-    t1 = <div>{expensiveNumber}</div>;
-    $[2] = expensiveNumber;
-    $[3] = t1;
+  if ($[0] !== x) {
+    t1 = calculateExpensiveNumber(x);
+    $[0] = x;
+    $[1] = t1;
   } else {
-    t1 = $[3];
+    t1 = $[1];
   }
-  return t1;
+  t0 = t1;
+  const expensiveNumber = t0;
+  let t2;
+  if ($[2] !== expensiveNumber) {
+    t2 = <div>{expensiveNumber}</div>;
+    $[2] = expensiveNumber;
+    $[3] = t2;
+  } else {
+    t2 = $[3];
+  }
+  return t2;
 }
 
 export const FIXTURE_ENTRYPOINT = {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/babel-existing-react-runtime-import.expect.md

@@ -36,28 +36,30 @@ function Component(props) {
   const $ = _c(4);
   const [x] = React.useState(0);
   let t0;
-  if ($[0] !== x) {
-    t0 = calculateExpensiveNumber(x);
-    $[0] = x;
-    $[1] = t0;
-  } else {
-    t0 = $[1];
-  }
-  const expensiveNumber = t0;
   let t1;
+  if ($[0] !== x) {
+    t1 = calculateExpensiveNumber(x);
+    $[0] = x;
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  t0 = t1;
+  const expensiveNumber = t0;
+  let t2;
   if ($[2] !== expensiveNumber) {
-    t1 = (
+    t2 = (
       <div>
         {expensiveNumber}
         {`${someImport}`}
       </div>
     );
     $[2] = expensiveNumber;
-    $[3] = t1;
+    $[3] = t2;
   } else {
-    t1 = $[3];
+    t2 = $[3];
   }
-  return t1;
+  return t2;
 }
 
 export const FIXTURE_ENTRYPOINT = {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/block-scoping-switch-variable-scoping.expect.md

@@ -36,22 +36,26 @@ import { useMemo } from "react";
 function Component(props) {
   const $ = _c(2);
   let t0;
+  let t1;
   if ($[0] !== props.value) {
-    t0 = { value: props.value };
+    t1 = { value: props.value };
     $[0] = props.value;
-    $[1] = t0;
+    $[1] = t1;
   } else {
-    t0 = $[1];
+    t1 = $[1];
   }
-  const handlers = t0;
+  const handlers = t1;
   bb0: switch (props.test) {
     case true: {
       console.log(handlers.value);
       break bb0;
     }
-    default:
+    default: {
+    }
   }
-  const outerHandlers = handlers;
+
+  t0 = handlers;
+  const outerHandlers = t0;
   return outerHandlers;
 }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/codegen-inline-iife-reassign.expect.md

@@ -37,9 +37,11 @@ function useTest() {
 
     const t1 = (w = 42);
     const t2 = w;
+    let t3;
 
     w = 999;
-    t0 = makeArray(t1, t2, 2);
+    t3 = 2;
+    t0 = makeArray(t1, t2, t3);
     $[0] = t0;
   } else {
     t0 = $[0];

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/codegen-inline-iife-storeprop.expect.md

@@ -37,9 +37,11 @@ function useTest() {
 
     const t1 = (w.x = 42);
     const t2 = w.x;
+    let t3;
 
     w.x = 999;
-    t0 = makeArray(t1, t2, 2);
+    t3 = 2;
+    t0 = makeArray(t1, t2, t3);
     $[0] = t0;
   } else {
     t0 = $[0];

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/codegen-inline-iife.expect.md

@@ -32,9 +32,11 @@ function useTest() {
   let t0;
   if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
     const t1 = print(1);
+    let t2;
 
     print(2);
-    t0 = makeArray(t1, 2);
+    t2 = 2;
+    t0 = makeArray(t1, t2);
     $[0] = t0;
   } else {
     t0 = $[0];

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/consecutive-use-memo.expect.md

@@ -29,33 +29,37 @@ function useHook(t0) {
   const $ = _c(7);
   const { a, b } = t0;
   let t1;
-  if ($[0] !== a) {
-    t1 = identity({ a });
-    $[0] = a;
-    $[1] = t1;
-  } else {
-    t1 = $[1];
-  }
-  const valA = t1;
   let t2;
-  if ($[2] !== b) {
-    t2 = identity([b]);
-    $[2] = b;
-    $[3] = t2;
+  if ($[0] !== a) {
+    t2 = identity({ a });
+    $[0] = a;
+    $[1] = t2;
   } else {
-    t2 = $[3];
+    t2 = $[1];
   }
-  const valB = t2;
+  t1 = t2;
+  const valA = t1;
   let t3;
+  let t4;
+  if ($[2] !== b) {
+    t4 = identity([b]);
+    $[2] = b;
+    $[3] = t4;
+  } else {
+    t4 = $[3];
+  }
+  t3 = t4;
+  const valB = t3;
+  let t5;
   if ($[4] !== valA || $[5] !== valB) {
-    t3 = [valA, valB];
+    t5 = [valA, valB];
     $[4] = valA;
     $[5] = valB;
-    $[6] = t3;
+    $[6] = t5;
   } else {
-    t3 = $[6];
+    t5 = $[6];
   }
-  return t3;
+  return t5;
 }
 
 export const FIXTURE_ENTRYPOINT = {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/context-variable-as-jsx-element-tag.expect.md

@@ -34,8 +34,10 @@ function Component(props) {
   let Component;
   if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
     Component = Stringify;
+    let t0;
 
-    Component = Component;
+    t0 = Component;
+    Component = t0;
     $[0] = Component;
   } else {
     Component = $[0];

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/deeply-nested-function-expressions-with-params.expect.md

@@ -28,18 +28,20 @@ import { c as _c } from "react/compiler-runtime";
 function Foo() {
   const $ = _c(1);
   let t0;
+  let t1;
   if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-    t0 = function a(t1) {
-      const x_0 = t1 === undefined ? _temp : t1;
-      return (function b(t2) {
-        const y_0 = t2 === undefined ? [] : t2;
+    t1 = function a(t2) {
+      const x_0 = t2 === undefined ? _temp : t2;
+      return (function b(t3) {
+        const y_0 = t3 === undefined ? [] : t3;
         return [x_0, y_0];
       })();
     };
-    $[0] = t0;
+    $[0] = t1;
   } else {
-    t0 = $[0];
+    t1 = $[0];
   }
+  t0 = t1;
   return t0;
 }
 function _temp() {}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/dominator.expect.md

@@ -67,7 +67,8 @@ function Component(props) {
     case "b": {
       break bb1;
     }
-    case "c":
+    case "c": {
+    }
     default: {
       x = 6;
     }

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/drop-methodcall-usememo.expect.md

@@ -28,6 +28,7 @@ import * as React from "react";
 
 function Component(props) {
   const $ = _c(2);
+  let t0;
   let x;
   if ($[0] !== props.value) {
     x = [];
@@ -37,7 +38,8 @@ function Component(props) {
   } else {
     x = $[1];
   }
-  const x_0 = x;
+  t0 = x;
+  const x_0 = t0;
   return x_0;
 }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error._todo.computed-lval-in-destructure.expect.md

@@ -15,19 +15,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Todo: (BuildHIR::lowerAssignment) Handle computed properties in ObjectPattern
-
-error._todo.computed-lval-in-destructure.ts:3:9
   1 | function Component(props) {
   2 |   const computedKey = props.key;
 > 3 |   const {[computedKey]: x} = props.val;
-    |          ^^^^^^^^^^^^^^^^ (BuildHIR::lowerAssignment) Handle computed properties in ObjectPattern
+    |          ^^^^^^^^^^^^^^^^ Todo: (BuildHIR::lowerAssignment) Handle computed properties in ObjectPattern (3:3)
   4 |
   5 |   return x;
   6 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.assign-global-in-component-tag-function.expect.md

@@ -15,19 +15,13 @@ function Component() {
 ## Error
 
 ```
-Found 1 error:
-Error: Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render)
-
-error.assign-global-in-component-tag-function.ts:3:4
   1 | function Component() {
   2 |   const Foo = () => {
 > 3 |     someGlobal = true;
-    |     ^^^^^^^^^^ Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render)
+    |     ^^^^^^^^^^ InvalidReact: Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render) (3:3)
   4 |   };
   5 |   return <Foo />;
   6 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.assign-global-in-jsx-children.expect.md

@@ -18,19 +18,13 @@ function Component() {
 ## Error
 
 ```
-Found 1 error:
-Error: Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render)
-
-error.assign-global-in-jsx-children.ts:3:4
   1 | function Component() {
   2 |   const foo = () => {
 > 3 |     someGlobal = true;
-    |     ^^^^^^^^^^ Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render)
+    |     ^^^^^^^^^^ InvalidReact: Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render) (3:3)
   4 |   };
   5 |   // Children are generally access/called during render, so
   6 |   // modifying a global in a children function is almost
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.assign-global-in-jsx-spread-attribute.expect.md

@@ -16,19 +16,13 @@ function Component() {
 ## Error
 
 ```
-Found 1 error:
-Error: Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render)
-
-error.assign-global-in-jsx-spread-attribute.ts:4:4
   2 | function Component() {
   3 |   const foo = () => {
 > 4 |     someGlobal = true;
-    |     ^^^^^^^^^^ Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render)
+    |     ^^^^^^^^^^ InvalidReact: Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render) (4:4)
   5 |   };
   6 |   return <div {...foo} />;
   7 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bailout-on-flow-suppression.expect.md

@@ -16,21 +16,13 @@ function Foo(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: React Compiler has skipped optimizing this component because one or more React rule violations were reported by Flow. React Compiler only works when your components follow all the rules of React, disabling them may result in unexpected or incorrect behavior
-
-$FlowFixMe[react-rule-hook].
-
-error.bailout-on-flow-suppression.ts:4:2
   2 |
   3 | function Foo(props) {
 > 4 |   // $FlowFixMe[react-rule-hook]
-    |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ React Compiler has skipped optimizing this component because one or more React rule violations were reported by Flow. React Compiler only works when your components follow all the rules of React, disabling them may result in unexpected or incorrect behavior
+    |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ InvalidReact: React Compiler has skipped optimizing this component because one or more React rule violations were reported by Flow. React Compiler only works when your components follow all the rules of React, disabling them may result in unexpected or incorrect behavior. $FlowFixMe[react-rule-hook] (4:4)
   5 |   useX();
   6 |   return null;
   7 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bailout-on-suppression-of-custom-rule.expect.md

@@ -19,35 +19,15 @@ function lowercasecomponent() {
 ## Error
 
 ```
-Found 2 errors:
-Error: React Compiler has skipped optimizing this component because one or more React ESLint rules were disabled. React Compiler only works when your components follow all the rules of React, disabling them may result in unexpected or incorrect behavior
-
-eslint-disable my-app/react-rule.
-
-error.bailout-on-suppression-of-custom-rule.ts:3:0
   1 | // @eslintSuppressionRules:["my-app","react-rule"]
   2 |
 > 3 | /* eslint-disable my-app/react-rule */
-    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ React Compiler has skipped optimizing this component because one or more React ESLint rules were disabled. React Compiler only works when your components follow all the rules of React, disabling them may result in unexpected or incorrect behavior
+    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ InvalidReact: React Compiler has skipped optimizing this component because one or more React ESLint rules were disabled. React Compiler only works when your components follow all the rules of React, disabling them may result in unexpected or incorrect behavior. eslint-disable my-app/react-rule (3:3)
+
+InvalidReact: React Compiler has skipped optimizing this component because one or more React ESLint rules were disabled. React Compiler only works when your components follow all the rules of React, disabling them may result in unexpected or incorrect behavior. eslint-disable-next-line my-app/react-rule (7:7)
   4 | function lowercasecomponent() {
   5 |   'use forget';
   6 |   const x = [];
-
-
-Error: React Compiler has skipped optimizing this component because one or more React ESLint rules were disabled. React Compiler only works when your components follow all the rules of React, disabling them may result in unexpected or incorrect behavior
-
-eslint-disable-next-line my-app/react-rule.
-
-error.bailout-on-suppression-of-custom-rule.ts:7:2
-   5 |   'use forget';
-   6 |   const x = [];
->  7 |   // eslint-disable-next-line my-app/react-rule
-     |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ React Compiler has skipped optimizing this component because one or more React ESLint rules were disabled. React Compiler only works when your components follow all the rules of React, disabling them may result in unexpected or incorrect behavior
-   8 |   return <div>{x}</div>;
-   9 | }
-  10 | /* eslint-enable my-app/react-rule */
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-old-inference-false-positive-ref-validation-in-use-effect.expect.md

@@ -36,10 +36,6 @@ function Component() {
 ## Error
 
 ```
-Found 2 errors:
-Error: This argument is a function which may reassign or mutate local variables after render, which can cause inconsistent behavior on subsequent renders. Consider using state instead
-
-error.bug-old-inference-false-positive-ref-validation-in-use-effect.ts:20:12
   18 |   );
   19 |   const ref = useRef(null);
 > 20 |   useEffect(() => {
@@ -51,24 +47,12 @@ error.bug-old-inference-false-positive-ref-validation-in-use-effect.ts:20:12
 > 23 |     }
      | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 > 24 |   }, [update]);
-     | ^^^^ This argument is a function which may reassign or mutate local variables after render, which can cause inconsistent behavior on subsequent renders. Consider using state instead
+     | ^^^^ InvalidReact: This argument is a function which may reassign or mutate local variables after render, which can cause inconsistent behavior on subsequent renders. Consider using state instead (20:24)
+
+InvalidReact: The function modifies a local variable here (14:14)
   25 |
   26 |   return 'ok';
   27 | }
-
-
-Error: The function modifies a local variable here
-
-error.bug-old-inference-false-positive-ref-validation-in-use-effect.ts:14:6
-  12 |         ...partialParams,
-  13 |       };
-> 14 |       nextParams.param = 'value';
-     |       ^^^^^^^^^^ The function modifies a local variable here
-  15 |       console.log(nextParams);
-  16 |     },
-  17 |     [params]
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.call-args-destructuring-asignment-complex.expect.md

@@ -14,19 +14,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Invariant: Const declaration cannot be referenced as an expression
-
-error.call-args-destructuring-asignment-complex.ts:3:9
   1 | function Component(props) {
   2 |   let x = makeObject();
 > 3 |   x.foo(([[x]] = makeObject()));
-    |          ^^^^^ Const declaration cannot be referenced as an expression
+    |          ^^^^^ Invariant: Const declaration cannot be referenced as an expression (3:3)
   4 |   return x;
   5 | }
   6 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.capitalized-function-call-aliased.expect.md

@@ -14,20 +14,12 @@ function Foo() {
 ## Error
 
 ```
-Found 1 error:
-Error: Capitalized functions are reserved for components, which must be invoked with JSX. If this is a component, render it with JSX. Otherwise, ensure that it has no hook calls and rename it to begin with a lowercase letter. Alternatively, if you know for a fact that this function is not a component, you can allowlist it via the compiler config
-
-Bar may be a component..
-
-error.capitalized-function-call-aliased.ts:4:2
   2 | function Foo() {
   3 |   let x = Bar;
 > 4 |   x(); // ERROR
-    |   ^^^ Capitalized functions are reserved for components, which must be invoked with JSX. If this is a component, render it with JSX. Otherwise, ensure that it has no hook calls and rename it to begin with a lowercase letter. Alternatively, if you know for a fact that this function is not a component, you can allowlist it via the compiler config
+    |   ^^^ InvalidReact: Capitalized functions are reserved for components, which must be invoked with JSX. If this is a component, render it with JSX. Otherwise, ensure that it has no hook calls and rename it to begin with a lowercase letter. Alternatively, if you know for a fact that this function is not a component, you can allowlist it via the compiler config. Bar may be a component. (4:4)
   5 | }
   6 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.capitalized-function-call.expect.md

@@ -15,21 +15,13 @@ function Component() {
 ## Error
 
 ```
-Found 1 error:
-Error: Capitalized functions are reserved for components, which must be invoked with JSX. If this is a component, render it with JSX. Otherwise, ensure that it has no hook calls and rename it to begin with a lowercase letter. Alternatively, if you know for a fact that this function is not a component, you can allowlist it via the compiler config
-
-SomeFunc may be a component..
-
-error.capitalized-function-call.ts:3:12
   1 | // @validateNoCapitalizedCalls
   2 | function Component() {
 > 3 |   const x = SomeFunc();
-    |             ^^^^^^^^^^ Capitalized functions are reserved for components, which must be invoked with JSX. If this is a component, render it with JSX. Otherwise, ensure that it has no hook calls and rename it to begin with a lowercase letter. Alternatively, if you know for a fact that this function is not a component, you can allowlist it via the compiler config
+    |             ^^^^^^^^^^ InvalidReact: Capitalized functions are reserved for components, which must be invoked with JSX. If this is a component, render it with JSX. Otherwise, ensure that it has no hook calls and rename it to begin with a lowercase letter. Alternatively, if you know for a fact that this function is not a component, you can allowlist it via the compiler config. SomeFunc may be a component. (3:3)
   4 |
   5 |   return x;
   6 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.capitalized-method-call.expect.md

@@ -15,21 +15,13 @@ function Component() {
 ## Error
 
 ```
-Found 1 error:
-Error: Capitalized functions are reserved for components, which must be invoked with JSX. If this is a component, render it with JSX. Otherwise, ensure that it has no hook calls and rename it to begin with a lowercase letter. Alternatively, if you know for a fact that this function is not a component, you can allowlist it via the compiler config
-
-SomeFunc may be a component..
-
-error.capitalized-method-call.ts:3:12
   1 | // @validateNoCapitalizedCalls
   2 | function Component() {
 > 3 |   const x = someGlobal.SomeFunc();
-    |             ^^^^^^^^^^^^^^^^^^^^^ Capitalized functions are reserved for components, which must be invoked with JSX. If this is a component, render it with JSX. Otherwise, ensure that it has no hook calls and rename it to begin with a lowercase letter. Alternatively, if you know for a fact that this function is not a component, you can allowlist it via the compiler config
+    |             ^^^^^^^^^^^^^^^^^^^^^ InvalidReact: Capitalized functions are reserved for components, which must be invoked with JSX. If this is a component, render it with JSX. Otherwise, ensure that it has no hook calls and rename it to begin with a lowercase letter. Alternatively, if you know for a fact that this function is not a component, you can allowlist it via the compiler config. SomeFunc may be a component. (3:3)
   4 |
   5 |   return x;
   6 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.capture-ref-for-mutation.expect.md

@@ -32,55 +32,19 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 4 errors:
-Error: This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef)
-
-error.capture-ref-for-mutation.ts:12:13
   10 |   };
   11 |   const moveLeft = {
 > 12 |     handler: handleKey('left')(),
-     |              ^^^^^^^^^^^^^^^^^ This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef)
+     |              ^^^^^^^^^^^^^^^^^ InvalidReact: This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef) (12:12)
+
+InvalidReact: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef) (12:12)
+
+InvalidReact: This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef) (15:15)
+
+InvalidReact: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef) (15:15)
   13 |   };
   14 |   const moveRight = {
   15 |     handler: handleKey('right')(),
-
-
-Error: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
-
-error.capture-ref-for-mutation.ts:12:13
-  10 |   };
-  11 |   const moveLeft = {
-> 12 |     handler: handleKey('left')(),
-     |              ^^^^^^^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
-  13 |   };
-  14 |   const moveRight = {
-  15 |     handler: handleKey('right')(),
-
-
-Error: This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef)
-
-error.capture-ref-for-mutation.ts:15:13
-  13 |   };
-  14 |   const moveRight = {
-> 15 |     handler: handleKey('right')(),
-     |              ^^^^^^^^^^^^^^^^^^ This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef)
-  16 |   };
-  17 |   return [moveLeft, moveRight];
-  18 | }
-
-
-Error: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
-
-error.capture-ref-for-mutation.ts:15:13
-  13 |   };
-  14 |   const moveRight = {
-> 15 |     handler: handleKey('right')(),
-     |              ^^^^^^^^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
-  16 |   };
-  17 |   return [moveLeft, moveRight];
-  18 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.conditional-hook-unknown-hook-react-namespace.expect.md

@@ -16,19 +16,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning)
-
-error.conditional-hook-unknown-hook-react-namespace.ts:4:8
   2 |   let x = null;
   3 |   if (props.cond) {
 > 4 |     x = React.useNonexistentHook();
-    |         ^^^^^^^^^^^^^^^^^^^^^^^^ Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning)
+    |         ^^^^^^^^^^^^^^^^^^^^^^^^ InvalidReact: Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning) (4:4)
   5 |   }
   6 |   return x;
   7 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.conditional-hooks-as-method-call.expect.md

@@ -16,19 +16,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning)
-
-error.conditional-hooks-as-method-call.ts:4:8
   2 |   let x = null;
   3 |   if (props.cond) {
 > 4 |     x = Foo.useFoo();
-    |         ^^^^^^^^^^ Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning)
+    |         ^^^^^^^^^^ InvalidReact: Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning) (4:4)
   5 |   }
   6 |   return x;
   7 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.context-variable-only-chained-assign.expect.md

@@ -28,21 +28,13 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 1 error:
-Error: Reassigning a variable after render has completed can cause inconsistent behavior on subsequent renders. Consider using state instead
-
-Variable `x` cannot be reassigned after render.
-
-error.context-variable-only-chained-assign.ts:10:19
    8 |   };
    9 |   const fn2 = () => {
 > 10 |     const copy2 = (x = 4);
-     |                    ^ Reassigning a variable after render has completed can cause inconsistent behavior on subsequent renders. Consider using state instead
+     |                    ^ InvalidReact: Reassigning a variable after render has completed can cause inconsistent behavior on subsequent renders. Consider using state instead. Variable `x` cannot be reassigned after render (10:10)
   11 |     return [invoke(fn1), copy2, identity(copy2)];
   12 |   };
   13 |   return invoke(fn2);
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.declare-reassign-variable-in-function-declaration.expect.md

@@ -17,21 +17,13 @@ function Component() {
 ## Error
 
 ```
-Found 1 error:
-Error: Reassigning a variable after render has completed can cause inconsistent behavior on subsequent renders. Consider using state instead
-
-Variable `x` cannot be reassigned after render.
-
-error.declare-reassign-variable-in-function-declaration.ts:4:4
   2 |   let x = null;
   3 |   function foo() {
 > 4 |     x = 9;
-    |     ^ Reassigning a variable after render has completed can cause inconsistent behavior on subsequent renders. Consider using state instead
+    |     ^ InvalidReact: Reassigning a variable after render has completed can cause inconsistent behavior on subsequent renders. Consider using state instead. Variable `x` cannot be reassigned after render (4:4)
   5 |   }
   6 |   const y = bar(foo);
   7 |   return <Child y={y} />;
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.default-param-accesses-local.expect.md

@@ -22,10 +22,6 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 1 error:
-Todo: (BuildHIR::node.lowerReorderableExpression) Expression type `ArrowFunctionExpression` cannot be safely reordered
-
-error.default-param-accesses-local.ts:3:6
   1 | function Component(
   2 |   x,
 > 3 |   y = () => {
@@ -33,12 +29,10 @@ error.default-param-accesses-local.ts:3:6
 > 4 |     return x;
     | ^^^^^^^^^^^^^
 > 5 |   }
-    | ^^^^ (BuildHIR::node.lowerReorderableExpression) Expression type `ArrowFunctionExpression` cannot be safely reordered
+    | ^^^^ Todo: (BuildHIR::node.lowerReorderableExpression) Expression type `ArrowFunctionExpression` cannot be safely reordered (3:5)
   6 | ) {
   7 |   return y();
   8 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.dont-hoist-inline-reference.expect.md

@@ -19,21 +19,13 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 1 error:
-Todo: [hoisting] EnterSSA: Expected identifier to be defined before being used
-
-Identifier x$1 is undefined.
-
-error.dont-hoist-inline-reference.ts:3:2
   1 | import {identity} from 'shared-runtime';
   2 | function useInvalid() {
 > 3 |   const x = identity(x);
-    |   ^^^^^^^^^^^^^^^^^^^^^^ [hoisting] EnterSSA: Expected identifier to be defined before being used
+    |   ^^^^^^^^^^^^^^^^^^^^^^ Todo: [hoisting] EnterSSA: Expected identifier to be defined before being used. Identifier x$1 is undefined (3:3)
   4 |   return x;
   5 | }
   6 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.emit-freeze-conflicting-global.expect.md

@@ -15,21 +15,13 @@ function useFoo(props) {
 ## Error
 
 ```
-Found 1 error:
-Todo: Encountered conflicting global in generated program
-
-Conflict from local binding __DEV__.
-
-error.emit-freeze-conflicting-global.ts:3:8
   1 | // @enableEmitFreeze @instrumentForget
   2 | function useFoo(props) {
 > 3 |   const __DEV__ = 'conflicting global';
-    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Encountered conflicting global in generated program
+    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Todo: Encountered conflicting global in generated program. Conflict from local binding __DEV__ (3:3)
   4 |   console.log(__DEV__);
   5 |   return foo(props.x);
   6 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.function-expression-references-variable-its-assigned-to.expect.md

@@ -15,21 +15,13 @@ function Component() {
 ## Error
 
 ```
-Found 1 error:
-Error: Reassigning a variable after render has completed can cause inconsistent behavior on subsequent renders. Consider using state instead
-
-Variable `callback` cannot be reassigned after render.
-
-error.function-expression-references-variable-its-assigned-to.ts:3:4
   1 | function Component() {
   2 |   let callback = () => {
 > 3 |     callback = null;
-    |     ^^^^^^^^ Reassigning a variable after render has completed can cause inconsistent behavior on subsequent renders. Consider using state instead
+    |     ^^^^^^^^ InvalidReact: Reassigning a variable after render has completed can cause inconsistent behavior on subsequent renders. Consider using state instead. Variable `callback` cannot be reassigned after render (3:3)
   4 |   };
   5 |   return <div onClick={callback} />;
   6 | }
-
-
 ```
           
       

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

@@ -24,12 +24,6 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Memoization: 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.
-
-error.hoist-optional-member-expression-with-conditional-optional.ts:4:23
    2 | import {ValidateMemoization} from 'shared-runtime';
    3 | function Component(props) {
 >  4 |   const data = useMemo(() => {
@@ -47,12 +41,10 @@ error.hoist-optional-member-expression-with-conditional-optional.ts:4:23
 > 10 |     return x;
      | ^^^^^^^^^^^^^^^^^
 > 11 |   }, [props?.items, props.cond]);
-     | ^^^^ 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
+     | ^^^^ CannotPreserveMemoization: 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 (4:11)
   12 |   return (
   13 |     <ValidateMemoization inputs={[props?.items, props.cond]} output={data} />
   14 |   );
-
-
 ```
           
       

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

@@ -24,12 +24,6 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Memoization: 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.
-
-error.hoist-optional-member-expression-with-conditional.ts:4:23
    2 | import {ValidateMemoization} from 'shared-runtime';
    3 | function Component(props) {
 >  4 |   const data = useMemo(() => {
@@ -47,12 +41,10 @@ error.hoist-optional-member-expression-with-conditional.ts:4:23
 > 10 |     return x;
      | ^^^^^^^^^^^^^^^^^
 > 11 |   }, [props?.items, props.cond]);
-     | ^^^^ 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
+     | ^^^^ CannotPreserveMemoization: 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 (4:11)
   12 |   return (
   13 |     <ValidateMemoization inputs={[props?.items, props.cond]} output={data} />
   14 |   );
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.hoisting-simple-function-declaration.expect.md

@@ -24,10 +24,6 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 1 error:
-Todo: Support functions with unreachable code that may contain hoisted declarations
-
-error.hoisting-simple-function-declaration.ts:6:2
    4 |   }
    5 |   return baz(); // OK: FuncDecls are HoistableDeclarations that have both declaration and value hoisting
 >  6 |   function baz() {
@@ -35,12 +31,10 @@ error.hoisting-simple-function-declaration.ts:6:2
 >  7 |     return bar();
      | ^^^^^^^^^^^^^^^^^
 >  8 |   }
-     | ^^^^ Support functions with unreachable code that may contain hoisted declarations
+     | ^^^^ Todo: Support functions with unreachable code that may contain hoisted declarations (6:8)
    9 | }
   10 |
   11 | export const FIXTURE_ENTRYPOINT = {
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.hook-call-freezes-captured-identifier.expect.md

@@ -29,19 +29,13 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 1 error:
-Error: Updating a value previously passed as an argument to a hook is not allowed. Consider moving the mutation before calling the hook
-
-error.hook-call-freezes-captured-identifier.ts:13:2
   11 |   });
   12 |
 > 13 |   x.value += count;
-     |   ^ Updating a value previously passed as an argument to a hook is not allowed. Consider moving the mutation before calling the hook
+     |   ^ InvalidReact: Updating a value previously passed as an argument to a hook is not allowed. Consider moving the mutation before calling the hook (13:13)
   14 |   return <Stringify x={x} cb={cb} />;
   15 | }
   16 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.hook-call-freezes-captured-memberexpr.expect.md

@@ -29,19 +29,13 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 1 error:
-Error: Updating a value previously passed as an argument to a hook is not allowed. Consider moving the mutation before calling the hook
-
-error.hook-call-freezes-captured-memberexpr.ts:13:2
   11 |   });
   12 |
 > 13 |   x.value += count;
-     |   ^ Updating a value previously passed as an argument to a hook is not allowed. Consider moving the mutation before calling the hook
+     |   ^ InvalidReact: Updating a value previously passed as an argument to a hook is not allowed. Consider moving the mutation before calling the hook (13:13)
   14 |   return <Stringify x={x} cb={cb} />;
   15 | }
   16 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.hook-property-load-local-hook.expect.md

@@ -23,31 +23,15 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 2 errors:
-Error: Hooks may not be referenced as normal values, they must be called. See https://react.dev/reference/rules/react-calls-components-and-hooks#never-pass-around-hooks-as-regular-values
-
-error.hook-property-load-local-hook.ts:7:12
    5 |
    6 | function Foo() {
 >  7 |   let bar = useFoo.useBar;
-     |             ^^^^^^^^^^^^^ Hooks may not be referenced as normal values, they must be called. See https://react.dev/reference/rules/react-calls-components-and-hooks#never-pass-around-hooks-as-regular-values
+     |             ^^^^^^^^^^^^^ InvalidReact: Hooks may not be referenced as normal values, they must be called. See https://react.dev/reference/rules/react-calls-components-and-hooks#never-pass-around-hooks-as-regular-values (7:7)
+
+InvalidReact: Hooks may not be referenced as normal values, they must be called. See https://react.dev/reference/rules/react-calls-components-and-hooks#never-pass-around-hooks-as-regular-values (8:8)
    8 |   return bar();
    9 | }
   10 |
-
-
-Error: Hooks may not be referenced as normal values, they must be called. See https://react.dev/reference/rules/react-calls-components-and-hooks#never-pass-around-hooks-as-regular-values
-
-error.hook-property-load-local-hook.ts:8:9
-   6 | function Foo() {
-   7 |   let bar = useFoo.useBar;
->  8 |   return bar();
-     |          ^^^ Hooks may not be referenced as normal values, they must be called. See https://react.dev/reference/rules/react-calls-components-and-hooks#never-pass-around-hooks-as-regular-values
-   9 | }
-  10 |
-  11 | export const FIXTURE_ENTRYPOINT = {
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.hook-ref-value.expect.md

@@ -20,31 +20,15 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 2 errors:
-Error: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
-
-error.hook-ref-value.ts:5:23
   3 | function Component(props) {
   4 |   const ref = useRef();
 > 5 |   useEffect(() => {}, [ref.current]);
-    |                        ^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
+    |                        ^^^^^^^^^^^ InvalidReact: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef) (5:5)
+
+InvalidReact: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef) (5:5)
   6 | }
   7 |
   8 | export const FIXTURE_ENTRYPOINT = {
-
-
-Error: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
-
-error.hook-ref-value.ts:5:23
-  3 | function Component(props) {
-  4 |   const ref = useRef();
-> 5 |   useEffect(() => {}, [ref.current]);
-    |                        ^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
-  6 | }
-  7 |
-  8 | export const FIXTURE_ENTRYPOINT = {
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-ReactUseMemo-async-callback.expect.md

@@ -15,22 +15,16 @@ function component(a, b) {
 ## Error
 
 ```
-Found 1 error:
-Error: useMemo callbacks may not be async or generator functions
-
-error.invalid-ReactUseMemo-async-callback.ts:2:24
   1 | function component(a, b) {
 > 2 |   let x = React.useMemo(async () => {
     |                         ^^^^^^^^^^^^^
 > 3 |     await a;
     | ^^^^^^^^^^^^
 > 4 |   }, []);
-    | ^^^^ useMemo callbacks may not be async or generator functions
+    | ^^^^ InvalidReact: useMemo callbacks may not be async or generator functions (2:4)
   5 |   return x;
   6 | }
   7 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-access-ref-during-render.expect.md

@@ -15,19 +15,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
-
-error.invalid-access-ref-during-render.ts:4:16
   2 | function Component(props) {
   3 |   const ref = useRef(null);
 > 4 |   const value = ref.current;
-    |                 ^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
+    |                 ^^^^^^^^^^^ InvalidReact: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef) (4:4)
   5 |   return value;
   6 | }
   7 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-aliased-ref-in-callback-invoked-during-render-.expect.md

@@ -19,18 +19,12 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
-
-error.invalid-aliased-ref-in-callback-invoked-during-render-.ts:9:33
    7 |     return <Foo item={item} current={current} />;
    8 |   };
 >  9 |   return <Items>{props.items.map(item => renderItem(item))}</Items>;
-     |                                  ^^^^^^^^^^^^^^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
+     |                                  ^^^^^^^^^^^^^^^^^^^^^^^^ InvalidReact: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef) (9:9)
   10 | }
   11 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-array-push-frozen.expect.md

@@ -15,19 +15,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Updating a value used previously in JSX is not allowed. Consider moving the mutation before the JSX
-
-error.invalid-array-push-frozen.ts:4:2
   2 |   const x = [];
   3 |   <div>{x}</div>;
 > 4 |   x.push(props.value);
-    |   ^ Updating a value used previously in JSX is not allowed. Consider moving the mutation before the JSX
+    |   ^ InvalidReact: Updating a value used previously in JSX is not allowed. Consider moving the mutation before the JSX (4:4)
   5 |   return x;
   6 | }
   7 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-assign-hook-to-local.expect.md

@@ -14,18 +14,12 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Hooks may not be referenced as normal values, they must be called. See https://react.dev/reference/rules/react-calls-components-and-hooks#never-pass-around-hooks-as-regular-values
-
-error.invalid-assign-hook-to-local.ts:2:12
   1 | function Component(props) {
 > 2 |   const x = useState;
-    |             ^^^^^^^^ Hooks may not be referenced as normal values, they must be called. See https://react.dev/reference/rules/react-calls-components-and-hooks#never-pass-around-hooks-as-regular-values
+    |             ^^^^^^^^ InvalidReact: Hooks may not be referenced as normal values, they must be called. See https://react.dev/reference/rules/react-calls-components-and-hooks#never-pass-around-hooks-as-regular-values (2:2)
   3 |   const state = x(null);
   4 |   return state[0];
   5 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-computed-store-to-frozen-value.expect.md

@@ -16,19 +16,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Updating a value used previously in JSX is not allowed. Consider moving the mutation before the JSX
-
-error.invalid-computed-store-to-frozen-value.ts:5:2
   3 |   // freeze
   4 |   <div>{x}</div>;
 > 5 |   x[0] = true;
-    |   ^ Updating a value used previously in JSX is not allowed. Consider moving the mutation before the JSX
+    |   ^ InvalidReact: Updating a value used previously in JSX is not allowed. Consider moving the mutation before the JSX (5:5)
   6 |   return x;
   7 | }
   8 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-conditional-call-aliased-hook-import.expect.md

@@ -18,19 +18,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning)
-
-error.invalid-conditional-call-aliased-hook-import.ts:6:11
   4 |   let data;
   5 |   if (props.cond) {
 > 6 |     data = readFragment();
-    |            ^^^^^^^^^^^^ Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning)
+    |            ^^^^^^^^^^^^ InvalidReact: Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning) (6:6)
   7 |   }
   8 |   return data;
   9 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-conditional-call-aliased-react-hook.expect.md

@@ -18,19 +18,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning)
-
-error.invalid-conditional-call-aliased-react-hook.ts:6:10
   4 |   let s;
   5 |   if (props.cond) {
 > 6 |     [s] = state();
-    |           ^^^^^ Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning)
+    |           ^^^^^ InvalidReact: Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning) (6:6)
   7 |   }
   8 |   return s;
   9 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-conditional-call-non-hook-imported-as-hook.expect.md

@@ -18,19 +18,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning)
-
-error.invalid-conditional-call-non-hook-imported-as-hook.ts:6:11
   4 |   let data;
   5 |   if (props.cond) {
 > 6 |     data = useArray();
-    |            ^^^^^^^^ Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning)
+    |            ^^^^^^^^ InvalidReact: Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning) (6:6)
   7 |   }
   8 |   return data;
   9 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-conditional-setState-in-useMemo.expect.md

@@ -22,31 +22,15 @@ function Component({item, cond}) {
 ## Error
 
 ```
-Found 2 errors:
-Error: Calling setState from useMemo may trigger an infinite loop. (https://react.dev/reference/react/useState)
-
-error.invalid-conditional-setState-in-useMemo.ts:7:6
    5 |   useMemo(() => {
    6 |     if (cond) {
 >  7 |       setPrevItem(item);
-     |       ^^^^^^^^^^^ Calling setState from useMemo may trigger an infinite loop. (https://react.dev/reference/react/useState)
+     |       ^^^^^^^^^^^ InvalidReact: Calling setState from useMemo may trigger an infinite loop. (https://react.dev/reference/react/useState) (7:7)
+
+InvalidReact: Calling setState from useMemo may trigger an infinite loop. (https://react.dev/reference/react/useState) (8:8)
    8 |       setState(0);
    9 |     }
   10 |   }, [cond, key, init]);
-
-
-Error: Calling setState from useMemo may trigger an infinite loop. (https://react.dev/reference/react/useState)
-
-error.invalid-conditional-setState-in-useMemo.ts:8:6
-   6 |     if (cond) {
-   7 |       setPrevItem(item);
->  8 |       setState(0);
-     |       ^^^^^^^^ Calling setState from useMemo may trigger an infinite loop. (https://react.dev/reference/react/useState)
-   9 |     }
-  10 |   }, [cond, key, init]);
-  11 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-delete-computed-property-of-frozen-value.expect.md

@@ -16,19 +16,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Updating a value used previously in JSX is not allowed. Consider moving the mutation before the JSX
-
-error.invalid-delete-computed-property-of-frozen-value.ts:5:9
   3 |   // freeze
   4 |   <div>{x}</div>;
 > 5 |   delete x[y];
-    |          ^ Updating a value used previously in JSX is not allowed. Consider moving the mutation before the JSX
+    |          ^ InvalidReact: Updating a value used previously in JSX is not allowed. Consider moving the mutation before the JSX (5:5)
   6 |   return x;
   7 | }
   8 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-delete-property-of-frozen-value.expect.md

@@ -16,19 +16,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Updating a value used previously in JSX is not allowed. Consider moving the mutation before the JSX
-
-error.invalid-delete-property-of-frozen-value.ts:5:9
   3 |   // freeze
   4 |   <div>{x}</div>;
 > 5 |   delete x.y;
-    |          ^ Updating a value used previously in JSX is not allowed. Consider moving the mutation before the JSX
+    |          ^ InvalidReact: Updating a value used previously in JSX is not allowed. Consider moving the mutation before the JSX (5:5)
   6 |   return x;
   7 | }
   8 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-destructure-assignment-to-global.expect.md

@@ -13,18 +13,12 @@ function useFoo(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render)
-
-error.invalid-destructure-assignment-to-global.ts:2:3
   1 | function useFoo(props) {
 > 2 |   [x] = props;
-    |    ^ Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render)
+    |    ^ InvalidReact: Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render) (2:2)
   3 |   return {x};
   4 | }
   5 |
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-destructure-to-local-global-variables.expect.md

@@ -15,19 +15,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render)
-
-error.invalid-destructure-to-local-global-variables.ts:3:6
   1 | function Component(props) {
   2 |   let a;
 > 3 |   [a, b] = props.value;
-    |       ^ Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render)
+    |       ^ InvalidReact: Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render) (3:3)
   4 |
   5 |   return [a, b];
   6 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-disallow-mutating-ref-in-render.expect.md

@@ -16,19 +16,13 @@ function Component() {
 ## Error
 
 ```
-Found 1 error:
-Error: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
-
-error.invalid-disallow-mutating-ref-in-render.ts:4:2
   2 | function Component() {
   3 |   const ref = useRef(null);
 > 4 |   ref.current = false;
-    |   ^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
+    |   ^^^^^^^^^^^ InvalidReact: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef) (4:4)
   5 |
   6 |   return <button ref={ref} />;
   7 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-disallow-mutating-refs-in-render-transitive.expect.md

@@ -21,31 +21,15 @@ function Component() {
 ## Error
 
 ```
-Found 2 errors:
-Error: This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef)
-
-error.invalid-disallow-mutating-refs-in-render-transitive.ts:9:2
    7 |   };
    8 |   const changeRef = setRef;
 >  9 |   changeRef();
-     |   ^^^^^^^^^ This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef)
+     |   ^^^^^^^^^ InvalidReact: This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef) (9:9)
+
+InvalidReact: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef) (9:9)
   10 |
   11 |   return <button ref={ref} />;
   12 | }
-
-
-Error: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
-
-error.invalid-disallow-mutating-refs-in-render-transitive.ts:9:2
-   7 |   };
-   8 |   const changeRef = setRef;
->  9 |   changeRef();
-     |   ^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
-  10 |
-  11 |   return <button ref={ref} />;
-  12 | }
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-eval-unsupported.expect.md

@@ -1,32 +0,0 @@
-
-## Input
-
-```javascript
-function Component(props) {
-  eval('props.x = true');
-  return <div />;
-}
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-Error: The 'eval' function is not supported
-
-Eval is an anti-pattern in JavaScript, and the code executed cannot be evaluated by React Compiler.
-
-error.invalid-eval-unsupported.ts:2:2
-  1 | function Component(props) {
-> 2 |   eval('props.x = true');
-    |   ^^^^ The 'eval' function is not supported
-  3 |   return <div />;
-  4 | }
-  5 |
-
-
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-eval-unsupported.js

@@ -1,4 +0,0 @@
-function Component(props) {
-  eval('props.x = true');
-  return <div />;
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-function-expression-mutates-immutable-value.expect.md

@@ -18,21 +18,13 @@ function Component(props) {
 ## Error
 
 ```
-Found 1 error:
-Error: Mutating a value returned from 'useState()', which should not be mutated. Use the setter function to update instead
-
-Found mutation of `x`.
-
-error.invalid-function-expression-mutates-immutable-value.ts:5:4
   3 |   const onChange = e => {
   4 |     // INVALID! should use copy-on-write and pass the new value
 > 5 |     x.value = e.target.value;
-    |     ^ Mutating a value returned from 'useState()', which should not be mutated. Use the setter function to update instead
+    |     ^ InvalidReact: Mutating a value returned from 'useState()', which should not be mutated. Use the setter function to update instead. Found mutation of `x` (5:5)
   6 |     setX(x);
   7 |   };
   8 |   return <input value={x.value} onChange={onChange} />;
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-global-reassignment-indirect.expect.md

@@ -35,19 +35,13 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 1 error:
-Error: Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render)
-
-error.invalid-global-reassignment-indirect.ts:9:4
    7 |
    8 |   const setGlobal = () => {
 >  9 |     someGlobal = true;
-     |     ^^^^^^^^^^ Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render)
+     |     ^^^^^^^^^^ InvalidReact: Unexpected reassignment of a variable which was defined outside of the component. Components and hooks should be pure and side-effect free, but variable reassignment is a form of side-effect. If this variable is used in rendering, use useState instead. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#side-effects-must-run-outside-of-render) (9:9)
   10 |   };
   11 |   const indirectSetGlobal = () => {
   12 |     setGlobal();
-
-
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-hoisting-setstate.expect.md

@@ -38,35 +38,15 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 2 errors:
-Error: This variable is accessed before it is declared, which may prevent it from updating as the assigned value changes over time
-
-Variable `setState` is accessed before it is declared.
-
-error.invalid-hoisting-setstate.ts:19:18
   17 |    * $2 = Function context=setState
   18 |    */
 > 19 |   useEffect(() => setState(2), []);
-     |                   ^^^^^^^^ This variable is accessed before it is declared, which may prevent it from updating as the assigned value changes over time
+     |                   ^^^^^^^^ InvalidReact: This variable is accessed before it is declared, which may prevent it from updating as the assigned value changes over time. Variable `setState` is accessed before it is declared (19:19)
+
+InvalidReact: This variable is accessed before it is declared, which prevents the earlier access from updating when this value changes over time. Variable `setState` is accessed before it is declared (21:21)
   20 |
   21 |   const [state, setState] = useState(0);
   22 |   return <Stringify state={state} />;
-
-
-Error: This variable is accessed before it is declared, which prevents the earlier access from updating when this value changes over time
-
-Variable `setState` is accessed before it is declared.
-
-error.invalid-hoisting-setstate.ts:21:16
-  19 |   useEffect(() => setState(2), []);
-  20 |
-> 21 |   const [state, setState] = useState(0);
-     |                 ^^^^^^^^ This variable is accessed before it is declared, which prevents the earlier access from updating when this value changes over time
-  22 |   return <Stringify state={state} />;
-  23 | }
-  24 |
-
-
 ```