[flow] Upgrade from 0.286 -> 0.292

Updates flow-typed definitions and adds suppressions for regressions
  in the updated type definitions:
  - TextDecoder: constructor options should be optional
  - TextEncoder: missing encodeInto method
  - ReadableStreamDefaultReader: cancel() returns Promise<void>
  - Animation types: missing optional properties
  - error-stack-parser: module type export

.eslintrc.js

@@ -635,7 +635,6 @@ module.exports = {
     FocusOptions: 'readonly',
     OptionalEffectTiming: 'readonly',
 
-    __REACT_ROOT_PATH_TEST__: 'readonly',
     spyOnDev: 'readonly',
     spyOnDevAndProd: 'readonly',
     spyOnProd: 'readonly',

.github/workflows/runtime_build_and_test.yml

@@ -382,6 +382,9 @@ jobs:
           -r=experimental --env=development,
           -r=experimental --env=production,
 
+          # Dev Tools
+          --project=devtools -r=experimental,
+
           # TODO: Update test config to support www build tests
           # - "-r=www-classic --env=development --variant=false"
           # - "-r=www-classic --env=production --variant=false"
@@ -447,50 +450,6 @@ jobs:
         run: ls -R build
       - run: yarn test --build ${{ matrix.test_params }} --shard=${{ matrix.shard }} --ci
 
-  test_build_devtools:
-    name: yarn test-build (devtools)
-    needs: [build_and_lint, runtime_node_modules_cache]
-    strategy:
-      fail-fast: false
-      matrix:
-        shard:
-          - 1/5
-          - 2/5
-          - 3/5
-          - 4/5
-          - 5/5
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          ref: ${{ github.event.inputs.commit_sha != '' && github.event.inputs.commit_sha || github.event.pull_request.head.sha || github.sha }}
-      - uses: actions/setup-node@v4
-        with:
-          node-version-file: '.nvmrc'
-          cache: yarn
-          cache-dependency-path: yarn.lock
-      - name: Restore cached node_modules
-        uses: actions/cache/restore@v4
-        id: node_modules
-        with:
-          path: |
-            **/node_modules
-          key: runtime-node_modules-v7-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
-          # Don't use restore-keys here. Otherwise the cache grows indefinitely.
-      - name: Ensure clean build directory
-        run: rm -rf build
-      - run: yarn install --frozen-lockfile
-        if: steps.node_modules.outputs.cache-hit != 'true'
-      - name: Restore archived build
-        uses: actions/download-artifact@v4
-        with:
-          pattern: _build_*
-          path: build
-          merge-multiple: true
-      - name: Display structure of build
-        run: ls -R build
-      - run: yarn test --build --project=devtools -r=experimental --shard=${{ matrix.shard }} --ci
-
   process_artifacts_combined:
     name: Process artifacts combined
     needs: [build_and_lint, runtime_node_modules_cache]

compiler/apps/playground/package.json

@@ -35,13 +35,13 @@
     "lru-cache": "^11.2.2",
     "lz-string": "^1.5.0",
     "monaco-editor": "^0.52.0",
-    "next": "15.5.9",
+    "next": "15.5.7",
     "notistack": "^3.0.0-alpha.7",
     "prettier": "^3.3.3",
     "pretty-format": "^29.3.1",
     "re-resizable": "^6.9.16",
-    "react": "19.2.3",
-    "react-dom": "19.2.3"
+    "react": "19.2",
+    "react-dom": "19.2"
   },
   "devDependencies": {
     "@types/node": "18.11.9",

compiler/apps/playground/yarn.lock

@@ -715,10 +715,10 @@
   dependencies:
     "@monaco-editor/loader" "^1.6.1"
 
-"@next/env@15.5.9":
-  version "15.5.9"
-  resolved "https://registry.yarnpkg.com/@next/env/-/env-15.5.9.tgz#53c2c34dc17cd87b61f70c6cc211e303123b2ab8"
-  integrity sha512-4GlTZ+EJM7WaW2HEZcyU317tIQDjkQIyENDLxYJfSWlfqguN+dHkZgyQTV/7ykvobU7yEH5gKvreNrH4B6QgIg==
+"@next/env@15.5.7":
+  version "15.5.7"
+  resolved "https://registry.yarnpkg.com/@next/env/-/env-15.5.7.tgz#4168db34ae3bc9fd9ad3b951d327f4cfc38d4362"
+  integrity sha512-4h6Y2NyEkIEN7Z8YxkA27pq6zTkS09bUSYC0xjd0NpwFxjnIKeZEeH591o5WECSmjpUhLn3H2QLJcDye3Uzcvg==
 
 "@next/eslint-plugin-next@15.5.2":
   version "15.5.2"
@@ -3204,12 +3204,12 @@ natural-compare@^1.4.0:
   resolved "https://registry.yarnpkg.com/natural-compare/-/natural-compare-1.4.0.tgz#4abebfeed7541f2c27acfb29bdbbd15c8d5ba4f7"
   integrity sha512-OWND8ei3VtNC9h7V60qff3SVobHr996CTwgxubgyQYEpg290h9J0buyECNNJexkFm5sOajh5G116RYA1c8ZMSw==
 
-next@15.5.9:
-  version "15.5.9"
-  resolved "https://registry.yarnpkg.com/next/-/next-15.5.9.tgz#1b80d05865cc27e710fb4dcfc6fd9e726ed12ad4"
-  integrity sha512-agNLK89seZEtC5zUHwtut0+tNrc0Xw4FT/Dg+B/VLEo9pAcS9rtTKpek3V6kVcVwsB2YlqMaHdfZL4eLEVYuCg==
+next@15.5.7:
+  version "15.5.7"
+  resolved "https://registry.yarnpkg.com/next/-/next-15.5.7.tgz#4507700b2bbcaf2c9fb7a9ad25c0dac2ba4a9a75"
+  integrity sha512-+t2/0jIJ48kUpGKkdlhgkv+zPTEOoXyr60qXe68eB/pl3CMJaLeIGjzp5D6Oqt25hCBiBTt8wEeeAzfJvUKnPQ==
   dependencies:
-    "@next/env" "15.5.9"
+    "@next/env" "15.5.7"
     "@swc/helpers" "0.5.15"
     caniuse-lite "^1.0.30001579"
     postcss "8.4.31"
@@ -3582,10 +3582,10 @@ re-resizable@^6.9.16:
   resolved "https://registry.yarnpkg.com/re-resizable/-/re-resizable-6.10.0.tgz#d684a096ab438f1a93f59ad3a580a206b0ce31ee"
   integrity sha512-hysSK0xmA5nz24HBVztlk4yCqCLCvS32E6ZpWxVKop9x3tqCa4yAj1++facrmkOf62JsJHjmjABdKxXofYioCw==
 
-react-dom@19.2.3:
-  version "19.2.3"
-  resolved "https://registry.yarnpkg.com/react-dom/-/react-dom-19.2.3.tgz#f0b61d7e5c4a86773889fcc1853af3ed5f215b17"
-  integrity sha512-yELu4WmLPw5Mr/lmeEpox5rw3RETacE++JgHqQzd2dg+YbJuat3jH4ingc+WPZhxaoFzdv9y33G+F7Nl5O0GBg==
+react-dom@19.2:
+  version "19.2.0"
+  resolved "https://registry.npmjs.org/react-dom/-/react-dom-19.2.0.tgz#00ed1e959c365e9a9d48f8918377465466ec3af8"
+  integrity sha512-UlbRu4cAiGaIewkPyiRGJk0imDN2T3JjieT6spoL2UeSf5od4n5LB/mQ4ejmxhCFT1tYe8IvaFulzynWovsEFQ==
   dependencies:
     scheduler "^0.27.0"
 
@@ -3599,10 +3599,10 @@ react-is@^18.0.0:
   resolved "https://registry.yarnpkg.com/react-is/-/react-is-18.3.1.tgz#e83557dc12eae63a99e003a46388b1dcbb44db7e"
   integrity sha512-/LLMVyas0ljjAtoYiPqYiL8VWXzUUdThrmU5+n20DZv+a+ClRoevUzw5JxU+Ieh5/c87ytoTBV9G1FiKfNJdmg==
 
-react@19.2.3:
-  version "19.2.3"
-  resolved "https://registry.yarnpkg.com/react/-/react-19.2.3.tgz#d83e5e8e7a258cf6b4fe28640515f99b87cd19b8"
-  integrity sha512-Ku/hhYbVjOQnXDZFv2+RibmLFGwFdeeKHFcOTlrt7xplBnya5OGn/hIRDsqDiSUcfORsDC7MPxwork8jBwsIWA==
+react@19.2:
+  version "19.2.0"
+  resolved "https://registry.npmjs.org/react/-/react-19.2.0.tgz#d33dd1721698f4376ae57a54098cb47fc75d93a5"
+  integrity sha512-tmbWg6W31tQLeB5cdIBOicJDJRR2KzXsV7uSK9iNfLWQ5bIZfxuPEHp7M8wiHyHnn0DD1i7w3Zmin0FtkrwoCQ==
 
 read-cache@^1.0.0:
   version "1.0.0"

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

@@ -132,12 +132,6 @@ export class CompilerDiagnostic {
     return new CompilerDiagnostic({...options, details: []});
   }
 
-  clone(): CompilerDiagnostic {
-    const cloned = CompilerDiagnostic.create({...this.options});
-    cloned.options.details = [...this.options.details];
-    return cloned;
-  }
-
   get reason(): CompilerDiagnosticOptions['reason'] {
     return this.options.reason;
   }

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

@@ -96,6 +96,7 @@ import {propagateScopeDependenciesHIR} from '../HIR/PropagateScopeDependenciesHI
 import {outlineJSX} from '../Optimization/OutlineJsx';
 import {optimizePropsMethodCalls} from '../Optimization/OptimizePropsMethodCalls';
 import {transformFire} from '../Transform';
+import {validateNoImpureFunctionsInRender} from '../Validation/ValidateNoImpureFunctionsInRender';
 import {validateStaticComponents} from '../Validation/ValidateStaticComponents';
 import {validateNoFreezingKnownMutableFunctions} from '../Validation/ValidateNoFreezingKnownMutableFunctions';
 import {inferMutationAliasingEffects} from '../Inference/InferMutationAliasingEffects';
@@ -106,7 +107,6 @@ import {nameAnonymousFunctions} from '../Transform/NameAnonymousFunctions';
 import {optimizeForSSR} from '../Optimization/OptimizeForSSR';
 import {validateExhaustiveDependencies} from '../Validation/ValidateExhaustiveDependencies';
 import {validateSourceLocations} from '../Validation/ValidateSourceLocations';
-import {validateNoImpureValuesInRender} from '../Validation/ValidateNoImpureValuesInRender';
 
 export type CompilerPipelineValue =
   | {kind: 'ast'; name: string; value: CodegenFunction}
@@ -271,36 +271,30 @@ function runWithEnvironment(
       assertValidMutableRanges(hir);
     }
 
+    if (env.config.validateRefAccessDuringRender) {
+      validateNoRefAccessInRender(hir).unwrap();
+    }
+
     if (env.config.validateNoSetStateInRender) {
       validateNoSetStateInRender(hir).unwrap();
     }
 
-    if (
-      env.config.validateNoDerivedComputationsInEffects_exp &&
-      env.outputMode === 'lint'
-    ) {
+    if (env.config.validateNoDerivedComputationsInEffects_exp) {
       env.logErrors(validateNoDerivedComputationsInEffects_exp(hir));
     } else if (env.config.validateNoDerivedComputationsInEffects) {
       validateNoDerivedComputationsInEffects(hir);
     }
 
-    if (env.config.validateNoSetStateInEffects && env.outputMode === 'lint') {
+    if (env.config.validateNoSetStateInEffects) {
       env.logErrors(validateNoSetStateInEffects(hir, env));
     }
 
-    if (env.config.validateNoJSXInTryStatements && env.outputMode === 'lint') {
+    if (env.config.validateNoJSXInTryStatements) {
       env.logErrors(validateNoJSXInTryStatement(hir));
     }
 
-    if (
-      env.config.validateNoImpureFunctionsInRender ||
-      env.config.validateRefAccessDuringRender
-    ) {
-      validateNoImpureValuesInRender(hir).unwrap();
-    }
-
-    if (env.config.validateRefAccessDuringRender) {
-      validateNoRefAccessInRender(hir).unwrap();
+    if (env.config.validateNoImpureFunctionsInRender) {
+      validateNoImpureFunctionsInRender(hir).unwrap();
     }
 
     validateNoFreezingKnownMutableFunctions(hir).unwrap();
@@ -326,11 +320,7 @@ function runWithEnvironment(
     value: hir,
   });
 
-  if (
-    env.enableValidations &&
-    env.config.validateStaticComponents &&
-    env.outputMode === 'lint'
-  ) {
+  if (env.enableValidations && env.config.validateStaticComponents) {
     env.logErrors(validateStaticComponents(hir));
   }
 

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

@@ -4026,7 +4026,6 @@ function lowerAssignment(
           pattern: {
             kind: 'ArrayPattern',
             items,
-            loc: lvalue.node.loc ?? GeneratedSource,
           },
         },
         value,
@@ -4204,7 +4203,6 @@ function lowerAssignment(
           pattern: {
             kind: 'ObjectPattern',
             properties,
-            loc: lvalue.node.loc ?? GeneratedSource,
           },
         },
         value,

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

@@ -225,15 +225,8 @@ export const EnvironmentConfigSchema = z.object({
 
   /**
    * Validate that dependencies supplied to effect hooks are exhaustive.
-   * Can be:
-   * - 'off': No validation (default)
-   * - 'all': Validate and report both missing and extra dependencies
-   * - 'missing-only': Only report missing dependencies
-   * - 'extra-only': Only report extra/unnecessary dependencies
    */
-  validateExhaustiveEffectDependencies: z
-    .enum(['off', 'all', 'missing-only', 'extra-only'])
-    .default('off'),
+  validateExhaustiveEffectDependencies: z.boolean().default(false),
 
   /**
    * When this is true, rather than pruning existing manual memoization but ensuring or validating

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

@@ -38,7 +38,7 @@ import {
   addObject,
 } from './ObjectShape';
 import {BuiltInType, ObjectType, PolyType} from './Types';
-import {AliasingSignatureConfig, TypeConfig} from './TypeSchema';
+import {TypeConfig} from './TypeSchema';
 import {assertExhaustive} from '../Utils/utils';
 import {isHookName} from './Environment';
 import {CompilerError, SourceLocation} from '..';
@@ -626,78 +626,6 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
   // TODO: rest of Global objects
 ];
 
-const RenderHookAliasing: (
-  reason: ValueReason,
-) => AliasingSignatureConfig = reason => ({
-  receiver: '@receiver',
-  params: [],
-  rest: '@rest',
-  returns: '@returns',
-  temporaries: [],
-  effects: [
-    // Freeze the arguments
-    {
-      kind: 'Freeze',
-      value: '@rest',
-      reason: ValueReason.HookCaptured,
-    },
-    // Render the arguments
-    {
-      kind: 'Render',
-      place: '@rest',
-    },
-    // Returns a frozen value
-    {
-      kind: 'Create',
-      into: '@returns',
-      value: ValueKind.Frozen,
-      reason,
-    },
-    // May alias any arguments into the return
-    {
-      kind: 'Alias',
-      from: '@rest',
-      into: '@returns',
-    },
-  ],
-});
-
-const EffectHookAliasing: AliasingSignatureConfig = {
-  receiver: '@receiver',
-  params: [],
-  rest: '@rest',
-  returns: '@returns',
-  temporaries: ['@effect'],
-  effects: [
-    // Freezes the function and deps
-    {
-      kind: 'Freeze',
-      value: '@rest',
-      reason: ValueReason.Effect,
-    },
-    // Internally creates an effect object that captures the function and deps
-    {
-      kind: 'Create',
-      into: '@effect',
-      value: ValueKind.Frozen,
-      reason: ValueReason.KnownReturnSignature,
-    },
-    // The effect stores the function and dependencies
-    {
-      kind: 'Capture',
-      from: '@rest',
-      into: '@effect',
-    },
-    // Returns undefined
-    {
-      kind: 'Create',
-      into: '@returns',
-      value: ValueKind.Primitive,
-      reason: ValueReason.KnownReturnSignature,
-    },
-  ],
-};
-
 /*
  * TODO(mofeiZ): We currently only store rest param effects for hooks.
  * now that FeatureFlag `enableTreatHooksAsFunctions` is removed we can
@@ -716,7 +644,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
         hookKind: 'useContext',
         returnValueKind: ValueKind.Frozen,
         returnValueReason: ValueReason.Context,
-        aliasing: RenderHookAliasing(ValueReason.Context),
       },
       BuiltInUseContextHookId,
     ),
@@ -731,7 +658,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       hookKind: 'useState',
       returnValueKind: ValueKind.Frozen,
       returnValueReason: ValueReason.State,
-      aliasing: RenderHookAliasing(ValueReason.State),
     }),
   ],
   [
@@ -744,7 +670,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       hookKind: 'useActionState',
       returnValueKind: ValueKind.Frozen,
       returnValueReason: ValueReason.State,
-      aliasing: RenderHookAliasing(ValueReason.HookCaptured),
     }),
   ],
   [
@@ -757,7 +682,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       hookKind: 'useReducer',
       returnValueKind: ValueKind.Frozen,
       returnValueReason: ValueReason.ReducerState,
-      aliasing: RenderHookAliasing(ValueReason.ReducerState),
     }),
   ],
   [
@@ -791,7 +715,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       calleeEffect: Effect.Read,
       hookKind: 'useMemo',
       returnValueKind: ValueKind.Frozen,
-      aliasing: RenderHookAliasing(ValueReason.HookCaptured),
     }),
   ],
   [
@@ -803,7 +726,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       calleeEffect: Effect.Read,
       hookKind: 'useCallback',
       returnValueKind: ValueKind.Frozen,
-      aliasing: RenderHookAliasing(ValueReason.HookCaptured),
     }),
   ],
   [
@@ -817,7 +739,41 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
         calleeEffect: Effect.Read,
         hookKind: 'useEffect',
         returnValueKind: ValueKind.Frozen,
-        aliasing: EffectHookAliasing,
+        aliasing: {
+          receiver: '@receiver',
+          params: [],
+          rest: '@rest',
+          returns: '@returns',
+          temporaries: ['@effect'],
+          effects: [
+            // Freezes the function and deps
+            {
+              kind: 'Freeze',
+              value: '@rest',
+              reason: ValueReason.Effect,
+            },
+            // Internally creates an effect object that captures the function and deps
+            {
+              kind: 'Create',
+              into: '@effect',
+              value: ValueKind.Frozen,
+              reason: ValueReason.KnownReturnSignature,
+            },
+            // The effect stores the function and dependencies
+            {
+              kind: 'Capture',
+              from: '@rest',
+              into: '@effect',
+            },
+            // Returns undefined
+            {
+              kind: 'Create',
+              into: '@returns',
+              value: ValueKind.Primitive,
+              reason: ValueReason.KnownReturnSignature,
+            },
+          ],
+        },
       },
       BuiltInUseEffectHookId,
     ),
@@ -833,7 +789,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
         calleeEffect: Effect.Read,
         hookKind: 'useLayoutEffect',
         returnValueKind: ValueKind.Frozen,
-        aliasing: EffectHookAliasing,
       },
       BuiltInUseLayoutEffectHookId,
     ),
@@ -849,7 +804,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
         calleeEffect: Effect.Read,
         hookKind: 'useInsertionEffect',
         returnValueKind: ValueKind.Frozen,
-        aliasing: EffectHookAliasing,
       },
       BuiltInUseInsertionEffectHookId,
     ),
@@ -863,7 +817,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       calleeEffect: Effect.Read,
       hookKind: 'useTransition',
       returnValueKind: ValueKind.Frozen,
-      aliasing: RenderHookAliasing(ValueReason.HookCaptured),
     }),
   ],
   [
@@ -876,7 +829,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
       hookKind: 'useOptimistic',
       returnValueKind: ValueKind.Frozen,
       returnValueReason: ValueReason.State,
-      aliasing: RenderHookAliasing(ValueReason.HookCaptured),
     }),
   ],
   [
@@ -890,7 +842,6 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
         returnType: {kind: 'Poly'},
         calleeEffect: Effect.Read,
         returnValueKind: ValueKind.Frozen,
-        aliasing: RenderHookAliasing(ValueReason.HookCaptured),
       },
       BuiltInUseOperatorId,
     ),

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

@@ -694,13 +694,11 @@ export type SpreadPattern = {
 export type ArrayPattern = {
   kind: 'ArrayPattern';
   items: Array<Place | SpreadPattern | Hole>;
-  loc: SourceLocation;
 };
 
 export type ObjectPattern = {
   kind: 'ObjectPattern';
   properties: Array<ObjectProperty | SpreadPattern>;
-  loc: SourceLocation;
 };
 
 export type ObjectPropertyKey =
@@ -1890,13 +1888,6 @@ export function isJsxType(type: Type): boolean {
   return type.kind === 'Object' && type.shapeId === 'BuiltInJsx';
 }
 
-export function isJsxOrJsxUnionType(type: Type): boolean {
-  return (
-    (type.kind === 'Object' && type.shapeId === 'BuiltInJsx') ||
-    (type.kind === 'Phi' && type.operands.some(op => isJsxOrJsxUnionType(op)))
-  );
-}
-
 export function isRefOrRefValue(id: Identifier): boolean {
   return isUseRefType(id) || isRefValueType(id);
 }
@@ -2065,23 +2056,4 @@ export function getHookKindForType(
   return null;
 }
 
-export function areEqualSourceLocations(
-  loc1: SourceLocation,
-  loc2: SourceLocation,
-): boolean {
-  if (typeof loc1 === 'symbol' || typeof loc2 === 'symbol') {
-    return false;
-  }
-  return (
-    loc1.filename === loc2.filename &&
-    loc1.identifierName === loc2.identifierName &&
-    loc1.start.line === loc2.start.line &&
-    loc1.start.column === loc2.start.column &&
-    loc1.start.index === loc2.start.index &&
-    loc1.end.line === loc2.end.line &&
-    loc1.end.column === loc2.end.column &&
-    loc1.end.index === loc2.end.index
-  );
-}
-
 export * from './Types';

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

@@ -988,7 +988,7 @@ export function createTemporaryPlace(
     identifier: makeTemporaryIdentifier(env.nextIdentifierId, loc),
     reactive: false,
     effect: Effect.Unknown,
-    loc,
+    loc: GeneratedSource,
   };
 }
 

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

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {CompilerError, ErrorCategory} from '../CompilerError';
+import {CompilerError} from '../CompilerError';
 import {AliasingEffect, AliasingSignature} from '../Inference/AliasingEffects';
 import {assertExhaustive} from '../Utils/utils';
 import {
@@ -190,22 +190,14 @@ function parseAliasingSignatureConfig(
           };
         }
         case 'Impure': {
-          const into = lookup(effect.into);
-          return {
-            kind: 'Impure',
-            into,
-            category: ErrorCategory.Purity,
-            description: effect.description,
-            reason: effect.reason,
-            sourceMessage: effect.sourceMessage,
-            usageMessage: effect.usageMessage,
-          };
-        }
-        case 'Render': {
           const place = lookup(effect.place);
           return {
-            kind: 'Render',
+            kind: 'Impure',
             place,
+            error: CompilerError.throwTodo({
+              reason: 'Support impure effect declarations',
+              loc: GeneratedSource,
+            }),
           };
         }
         case 'Apply': {
@@ -1521,11 +1513,6 @@ export const DefaultNonmutatingHook = addHook(
           value: '@rest',
           reason: ValueReason.HookCaptured,
         },
-        // Render the arguments
-        {
-          kind: 'Render',
-          place: '@rest',
-        },
         // Returns a frozen value
         {
           kind: 'Create',

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

@@ -1009,7 +1009,7 @@ export function printAliasingEffect(effect: AliasingEffect): string {
       return `MutateGlobal ${printPlaceForAliasEffect(effect.place)} reason=${JSON.stringify(effect.error.reason)}`;
     }
     case 'Impure': {
-      return `Impure ${printPlaceForAliasEffect(effect.into)} reason=${effect.reason} description=${effect.description}`;
+      return `Impure ${printPlaceForAliasEffect(effect.place)} reason=${JSON.stringify(effect.error.reason)}`;
     }
     case 'Render': {
       return `Render ${printPlaceForAliasEffect(effect.place)}`;

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

@@ -185,29 +185,11 @@ export const ApplyEffectSchema: z.ZodType<ApplyEffectConfig> = z.object({
 
 export type ImpureEffectConfig = {
   kind: 'Impure';
-  into: string;
-  reason: string;
-  description: string;
-  sourceMessage: string;
-  usageMessage: string;
+  place: string;
 };
 
 export const ImpureEffectSchema: z.ZodType<ImpureEffectConfig> = z.object({
   kind: z.literal('Impure'),
-  into: LifetimeIdSchema,
-  reason: z.string(),
-  description: z.string(),
-  sourceMessage: z.string(),
-  usageMessage: z.string(),
-});
-
-export type RenderEffectConfig = {
-  kind: 'Render';
-  place: string;
-};
-
-export const RenderEffectSchema: z.ZodType<RenderEffectConfig> = z.object({
-  kind: z.literal('Render'),
   place: LifetimeIdSchema,
 });
 
@@ -222,8 +204,7 @@ export type AliasingEffectConfig =
   | ImpureEffectConfig
   | MutateEffectConfig
   | MutateTransitiveConditionallyConfig
-  | ApplyEffectConfig
-  | RenderEffectConfig;
+  | ApplyEffectConfig;
 
 export const AliasingEffectSchema: z.ZodType<AliasingEffectConfig> = z.union([
   FreezeEffectSchema,

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

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {CompilerDiagnostic, ErrorCategory} from '../CompilerError';
+import {CompilerDiagnostic} from '../CompilerError';
 import {
   FunctionExpression,
   GeneratedSource,
@@ -162,15 +162,7 @@ export type AliasingEffect =
   /**
    * Indicates a side-effect that is not safe during render
    */
-  | {
-      kind: 'Impure';
-      into: Place;
-      category: ErrorCategory;
-      reason: string;
-      description: string;
-      usageMessage: string;
-      sourceMessage: string;
-    }
+  | {kind: 'Impure'; place: Place; error: CompilerDiagnostic}
   /**
    * Indicates that a given place is accessed during render. Used to distingush
    * hook arguments that are known to be called immediately vs those used for
@@ -230,14 +222,6 @@ export function hashEffect(effect: AliasingEffect): string {
       return [effect.kind, effect.value.identifier.id, effect.reason].join(':');
     }
     case 'Impure':
-      return [
-        effect.kind,
-        effect.into.identifier.id,
-        effect.reason,
-        effect.description,
-        effect.usageMessage,
-        effect.sourceMessage,
-      ].join(':');
     case 'Render': {
       return [effect.kind, effect.place.identifier.id].join(':');
     }

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

@@ -8,7 +8,7 @@
 import {BlockId, computePostDominatorTree, HIRFunction, Place} from '../HIR';
 import {PostDominator} from '../HIR/Dominator';
 
-export type ControlDominators = (id: BlockId) => Place | null;
+export type ControlDominators = (id: BlockId) => boolean;
 
 /**
  * Returns an object that lazily calculates whether particular blocks are controlled
@@ -23,7 +23,7 @@ export function createControlDominators(
   });
   const postDominatorFrontierCache = new Map<BlockId, Set<BlockId>>();
 
-  function isControlledBlock(id: BlockId): Place | null {
+  function isControlledBlock(id: BlockId): boolean {
     let controlBlocks = postDominatorFrontierCache.get(id);
     if (controlBlocks === undefined) {
       controlBlocks = postDominatorFrontier(fn, postDominators, id);
@@ -35,24 +35,24 @@ export function createControlDominators(
         case 'if':
         case 'branch': {
           if (isControlVariable(controlBlock.terminal.test)) {
-            return controlBlock.terminal.test;
+            return true;
           }
           break;
         }
         case 'switch': {
           if (isControlVariable(controlBlock.terminal.test)) {
-            return controlBlock.terminal.test;
+            return true;
           }
           for (const case_ of controlBlock.terminal.cases) {
             if (case_.test !== null && isControlVariable(case_.test)) {
-              return case_.test;
+              return true;
             }
           }
           break;
         }
       }
     }
-    return null;
+    return false;
   }
 
   return isControlledBlock;

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

@@ -27,12 +27,11 @@ import {
   InstructionKind,
   InstructionValue,
   isArrayType,
-  isJsxOrJsxUnionType,
+  isJsxType,
   isMapType,
   isPrimitiveType,
   isRefOrRefValue,
   isSetType,
-  isUseRefType,
   makeIdentifierId,
   Phi,
   Place,
@@ -71,7 +70,6 @@ import {
   MutationReason,
 } from './AliasingEffects';
 import {ErrorCategory} from '../CompilerError';
-import {REF_ERROR_DESCRIPTION} from '../Validation/ValidateNoRefAccessInRender';
 
 const DEBUG = false;
 
@@ -571,21 +569,14 @@ function inferBlock(
       terminal.effects = effects.length !== 0 ? effects : null;
     }
   } else if (terminal.kind === 'return') {
-    terminal.effects = [
-      context.internEffect({
-        kind: 'Alias',
-        from: terminal.value,
-        into: context.fn.returns,
-      }),
-    ];
     if (!context.isFuctionExpression) {
-      terminal.effects.push(
+      terminal.effects = [
         context.internEffect({
           kind: 'Freeze',
           value: terminal.value,
           reason: ValueReason.JsxCaptured,
         }),
-      );
+      ];
     }
   }
 }
@@ -1982,20 +1973,6 @@ function computeSignatureForInstruction(
           into: lvalue,
         });
       }
-      if (
-        env.config.validateRefAccessDuringRender &&
-        isUseRefType(value.object.identifier)
-      ) {
-        effects.push({
-          kind: 'Impure',
-          into: lvalue,
-          category: ErrorCategory.Refs,
-          reason: `Cannot access ref value during render`,
-          description: REF_ERROR_DESCRIPTION,
-          sourceMessage: `Ref is initially accessed`,
-          usageMessage: `Ref value is used during render`,
-        });
-      }
       break;
     }
     case 'PropertyStore':
@@ -2160,15 +2137,6 @@ function computeSignatureForInstruction(
           into: lvalue,
         });
       }
-      if (value.children != null) {
-        // Children are typically called during render, not used as an event/effect callback
-        for (const child of value.children) {
-          effects.push({
-            kind: 'Render',
-            place: child,
-          });
-        }
-      }
       if (value.kind === 'JsxExpression') {
         if (value.tag.kind === 'Identifier') {
           // Tags are render function, by definition they're called during render
@@ -2177,20 +2145,29 @@ function computeSignatureForInstruction(
             place: value.tag,
           });
         }
-        for (const prop of value.props) {
-          const place =
-            prop.kind === 'JsxAttribute' ? prop.place : prop.argument;
-          if (place.identifier.type.kind === 'Function') {
-            if (isJsxOrJsxUnionType(place.identifier.type.return)) {
-              effects.push({
-                kind: 'Render',
-                place,
-              });
-            }
-          } else {
+        if (value.children != null) {
+          // Children are typically called during render, not used as an event/effect callback
+          for (const child of value.children) {
             effects.push({
               kind: 'Render',
-              place,
+              place: child,
+            });
+          }
+        }
+        for (const prop of value.props) {
+          if (
+            prop.kind === 'JsxAttribute' &&
+            prop.place.identifier.type.kind === 'Function' &&
+            (isJsxType(prop.place.identifier.type.return) ||
+              (prop.place.identifier.type.return.kind === 'Phi' &&
+                prop.place.identifier.type.return.operands.some(operand =>
+                  isJsxType(operand),
+                )))
+          ) {
+            // Any props which return jsx are assumed to be called during render
+            effects.push({
+              kind: 'Render',
+              place: prop.place,
             });
           }
         }
@@ -2446,7 +2423,7 @@ function computeEffectsForLegacySignature(
   lvalue: Place,
   receiver: Place,
   args: Array<Place | SpreadPattern | Hole>,
-  _loc: SourceLocation,
+  loc: SourceLocation,
 ): Array<AliasingEffect> {
   const returnValueReason = signature.returnValueReason ?? ValueReason.Other;
   const effects: Array<AliasingEffect> = [];
@@ -2459,18 +2436,20 @@ function computeEffectsForLegacySignature(
   if (signature.impure && state.env.config.validateNoImpureFunctionsInRender) {
     effects.push({
       kind: 'Impure',
-      into: lvalue,
-      category: ErrorCategory.Purity,
-      reason: 'Cannot access impure value during render',
-      description:
-        'Calling an impure function can produce unstable results that update ' +
-        'unpredictably when the component happens to re-render. ' +
-        '(https://react.dev/reference/rules/components-and-hooks-must-be-pure#components-and-hooks-must-be-idempotent)',
-      sourceMessage:
-        signature.canonicalName != null
-          ? `\`${signature.canonicalName}\` is an impure function.`
-          : 'This function is impure',
-      usageMessage: 'Cannot access impure value during render',
+      place: receiver,
+      error: CompilerDiagnostic.create({
+        category: ErrorCategory.Purity,
+        reason: 'Cannot call impure function during render',
+        description:
+          (signature.canonicalName != null
+            ? `\`${signature.canonicalName}\` is an impure function. `
+            : '') +
+          'Calling an impure function can produce unstable results that update unpredictably when the component happens to re-render. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#components-and-hooks-must-be-idempotent)',
+      }).withDetails({
+        kind: 'error',
+        loc,
+        message: 'Cannot call impure function',
+      }),
     });
   }
   if (signature.knownIncompatible != null && state.env.enableValidations) {
@@ -2769,23 +2748,7 @@ function computeEffectsForSignature(
         }
         break;
       }
-      case 'Impure': {
-        if (env.config.validateNoImpureFunctionsInRender) {
-          const values = substitutions.get(effect.into.identifier.id) ?? [];
-          for (const value of values) {
-            effects.push({
-              kind: effect.kind,
-              into: value,
-              category: effect.category,
-              reason: effect.reason,
-              description: effect.description,
-              sourceMessage: effect.sourceMessage,
-              usageMessage: effect.usageMessage,
-            });
-          }
-        }
-        break;
-      }
+      case 'Impure':
       case 'MutateFrozen':
       case 'MutateGlobal': {
         const values = substitutions.get(effect.place.identifier.id) ?? [];

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

@@ -19,7 +19,6 @@ import {
   ValueReason,
   Place,
   isPrimitiveType,
-  isUseRefType,
 } from '../HIR/HIR';
 import {
   eachInstructionLValue,
@@ -29,9 +28,6 @@ import {
 import {assertExhaustive, getOrInsertWith} from '../Utils/utils';
 import {Err, Ok, Result} from '../Utils/Result';
 import {AliasingEffect, MutationReason} from './AliasingEffects';
-import {printIdentifier, printType} from '../HIR/PrintHIR';
-
-const DEBUG = false;
 
 /**
  * This pass builds an abstract model of the heap and interprets the effects of the
@@ -108,6 +104,7 @@ export function inferMutationAliasingRanges(
     reason: MutationReason | null;
   }> = [];
   const renders: Array<{index: number; place: Place}> = [];
+
   let index = 0;
 
   const errors = new CompilerError();
@@ -200,12 +197,14 @@ export function inferMutationAliasingRanges(
           });
         } else if (
           effect.kind === 'MutateFrozen' ||
-          effect.kind === 'MutateGlobal'
+          effect.kind === 'MutateGlobal' ||
+          effect.kind === 'Impure'
         ) {
           errors.pushDiagnostic(effect.error);
           functionEffects.push(effect);
         } else if (effect.kind === 'Render') {
           renders.push({index: index++, place: effect.place});
+          functionEffects.push(effect);
         }
       }
     }
@@ -215,6 +214,10 @@ export function inferMutationAliasingRanges(
         state.assign(index, from, into);
       }
     }
+    if (block.terminal.kind === 'return') {
+      state.assign(index++, block.terminal.value, fn.returns);
+    }
+
     if (
       (block.terminal.kind === 'maybe-throw' ||
         block.terminal.kind === 'return') &&
@@ -241,11 +244,6 @@ export function inferMutationAliasingRanges(
   }
 
   for (const mutation of mutations) {
-    if (DEBUG) {
-      console.log(
-        `[${mutation.index}] mutate ${printIdentifier(mutation.place.identifier)}`,
-      );
-    }
     state.mutate(
       mutation.index,
       mutation.place.identifier,
@@ -257,16 +255,8 @@ export function inferMutationAliasingRanges(
       errors,
     );
   }
-  if (DEBUG) {
-    console.log(state.debug());
-  }
   for (const render of renders) {
-    if (DEBUG) {
-      console.log(
-        `[${render.index}] render ${printIdentifier(render.place.identifier)}`,
-      );
-    }
-    state.render(render.index, render.place, errors);
+    state.render(render.index, render.place.identifier, errors);
   }
   for (const param of [...fn.context, ...fn.params]) {
     const place = param.kind === 'Identifier' ? param : param.place;
@@ -525,13 +515,6 @@ export function inferMutationAliasingRanges(
   const ignoredErrors = new CompilerError();
   for (const param of [...fn.params, ...fn.context, fn.returns]) {
     const place = param.kind === 'Identifier' ? param : param.place;
-    const node = state.nodes.get(place.identifier);
-    if (node != null && node.render != null) {
-      functionEffects.push({
-        kind: 'Render',
-        place: place,
-      });
-    }
     tracked.push(place);
   }
   for (const into of tracked) {
@@ -594,6 +577,7 @@ export function inferMutationAliasingRanges(
 function appendFunctionErrors(errors: CompilerError, fn: HIRFunction): void {
   for (const effect of fn.aliasingEffects ?? []) {
     switch (effect.kind) {
+      case 'Impure':
       case 'MutateFrozen':
       case 'MutateGlobal': {
         errors.pushDiagnostic(effect.error);
@@ -628,74 +612,10 @@ type Node = {
     | {kind: 'Object'}
     | {kind: 'Phi'}
     | {kind: 'Function'; function: HIRFunction};
-  render: Place | null;
 };
-
-function _printNode(node: Node): string {
-  const out: Array<string> = [];
-  debugNode(out, node);
-  return out.join('\n');
-}
-function debugNode(out: Array<string>, node: Node): void {
-  out.push(
-    printIdentifier(node.id) +
-      printType(node.id.type) +
-      ` lastMutated=[${node.lastMutated}]`,
-  );
-  if (node.transitive != null) {
-    out.push(`  transitive=${node.transitive.kind}`);
-  }
-  if (node.local != null) {
-    out.push(`  local=${node.local.kind}`);
-  }
-  if (node.mutationReason != null) {
-    out.push(`  mutationReason=${node.mutationReason?.kind}`);
-  }
-  const edges: Array<{
-    index: number;
-    direction: '<=' | '=>';
-    kind: string;
-    id: Identifier;
-  }> = [];
-  for (const [alias, index] of node.createdFrom) {
-    edges.push({index, direction: '<=', kind: 'createFrom', id: alias});
-  }
-  for (const [alias, index] of node.aliases) {
-    edges.push({index, direction: '<=', kind: 'alias', id: alias});
-  }
-  for (const [alias, index] of node.maybeAliases) {
-    edges.push({index, direction: '<=', kind: 'alias?', id: alias});
-  }
-  for (const [alias, index] of node.captures) {
-    edges.push({index, direction: '<=', kind: 'capture', id: alias});
-  }
-  for (const edge of node.edges) {
-    edges.push({
-      index: edge.index,
-      direction: '=>',
-      kind: edge.kind,
-      id: edge.node,
-    });
-  }
-  edges.sort((a, b) => a.index - b.index);
-  for (const edge of edges) {
-    out.push(
-      `  [${edge.index}] ${edge.direction} ${edge.kind} ${printIdentifier(edge.id)}`,
-    );
-  }
-}
-
 class AliasingState {
   nodes: Map<Identifier, Node> = new Map();
 
-  debug(): string {
-    const items: Array<string> = [];
-    for (const [_id, node] of this.nodes) {
-      debugNode(items, node);
-    }
-    return items.join('\n');
-  }
-
   create(place: Place, value: Node['value']): void {
     this.nodes.set(place.identifier, {
       id: place.identifier,
@@ -709,7 +629,6 @@ class AliasingState {
       lastMutated: 0,
       mutationReason: null,
       value,
-      render: null,
     });
   }
 
@@ -762,9 +681,9 @@ class AliasingState {
     }
   }
 
-  render(index: number, start: Place, errors: CompilerError): void {
+  render(index: number, start: Identifier, errors: CompilerError): void {
     const seen = new Set<Identifier>();
-    const queue: Array<Identifier> = [start.identifier];
+    const queue: Array<Identifier> = [start];
     while (queue.length !== 0) {
       const current = queue.pop()!;
       if (seen.has(current)) {
@@ -772,34 +691,11 @@ class AliasingState {
       }
       seen.add(current);
       const node = this.nodes.get(current);
-      if (node == null || isUseRefType(node.id)) {
-        if (DEBUG) {
-          console.log(`  render ${printIdentifier(current)}: skip mutated/ref`);
-        }
+      if (node == null || node.transitive != null || node.local != null) {
         continue;
       }
-      if (
-        node.local == null &&
-        node.transitive == null &&
-        node.value.kind === 'Function'
-      ) {
-        const returns = node.value.function.returns;
-        if (
-          isJsxType(returns.identifier.type) ||
-          (returns.identifier.type.kind === 'Phi' &&
-            returns.identifier.type.operands.some(operand =>
-              isJsxType(operand),
-            ))
-        ) {
-          appendFunctionErrors(errors, node.value.function);
-        }
-        if (DEBUG) {
-          console.log(`  render ${printIdentifier(current)}: skip function`);
-        }
-        continue;
-      }
-      if (node.render == null) {
-        node.render = start;
+      if (node.value.kind === 'Function') {
+        appendFunctionErrors(errors, node.value.function);
       }
       for (const [alias, when] of node.createdFrom) {
         if (when >= index) {
@@ -813,12 +709,6 @@ class AliasingState {
         }
         queue.push(alias);
       }
-      for (const [alias, when] of node.maybeAliases) {
-        if (when >= index) {
-          continue;
-        }
-        queue.push(alias);
-      }
       for (const [capture, when] of node.captures) {
         if (when >= index) {
           continue;

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

@@ -515,7 +515,6 @@ function emitDestructureProps(
         pattern: {
           kind: 'ObjectPattern',
           properties,
-          loc: GeneratedSource,
         },
         kind: InstructionKind.Let,
       },

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

@@ -702,7 +702,7 @@ function codegenReactiveScope(
     outputComments.push(name.name);
     if (!cx.hasDeclared(identifier)) {
       statements.push(
-        t.variableDeclaration('let', [createVariableDeclarator(name, null)]),
+        t.variableDeclaration('let', [t.variableDeclarator(name)]),
       );
     }
     cacheLoads.push({name, index, value: wrapCacheDep(cx, name)});
@@ -1387,7 +1387,7 @@ function codegenInstructionNullable(
           suggestions: null,
         });
         return createVariableDeclaration(instr.loc, 'const', [
-          createVariableDeclarator(codegenLValue(cx, lvalue), value),
+          t.variableDeclarator(codegenLValue(cx, lvalue), value),
         ]);
       }
       case InstructionKind.Function: {
@@ -1451,7 +1451,7 @@ function codegenInstructionNullable(
           suggestions: null,
         });
         return createVariableDeclaration(instr.loc, 'let', [
-          createVariableDeclarator(codegenLValue(cx, lvalue), value),
+          t.variableDeclarator(codegenLValue(cx, lvalue), value),
         ]);
       }
       case InstructionKind.Reassign: {
@@ -1691,9 +1691,6 @@ function withLoc<T extends (...args: Array<any>) => t.Node>(
   };
 }
 
-const createIdentifier = withLoc(t.identifier);
-const createArrayPattern = withLoc(t.arrayPattern);
-const createObjectPattern = withLoc(t.objectPattern);
 const createBinaryExpression = withLoc(t.binaryExpression);
 const createExpressionStatement = withLoc(t.expressionStatement);
 const _createLabelledStatement = withLoc(t.labeledStatement);
@@ -1725,31 +1722,6 @@ const createTryStatement = withLoc(t.tryStatement);
 const createBreakStatement = withLoc(t.breakStatement);
 const createContinueStatement = withLoc(t.continueStatement);
 
-function createVariableDeclarator(
-  id: t.LVal,
-  init?: t.Expression | null,
-): t.VariableDeclarator {
-  const node = t.variableDeclarator(id, init);
-
-  /*
-   * The variable declarator location is not preserved in HIR, however, we can use the
-   * start location of the id and the end location of the init to recreate the
-   * exact original variable declarator location.
-   *
-   * Or if init is null, we likely have a declaration without an initializer, so we can use the id.loc.end as the end location.
-   */
-  if (id.loc && (init === null || init?.loc)) {
-    node.loc = {
-      start: id.loc.start,
-      end: init?.loc?.end ?? id.loc.end,
-      filename: id.loc.filename,
-      identifierName: undefined,
-    };
-  }
-
-  return node;
-}
-
 function createHookGuard(
   guard: ExternalFunction,
   context: ProgramContext,
@@ -1857,7 +1829,7 @@ function codegenInstruction(
       );
     } else {
       return createVariableDeclaration(instr.loc, 'const', [
-        createVariableDeclarator(
+        t.variableDeclarator(
           convertIdentifier(instr.lvalue.identifier),
           expressionValue,
         ),
@@ -2784,7 +2756,7 @@ function codegenArrayPattern(
 ): t.ArrayPattern {
   const hasHoles = !pattern.items.every(e => e.kind !== 'Hole');
   if (hasHoles) {
-    const result = createArrayPattern(pattern.loc, []);
+    const result = t.arrayPattern([]);
     /*
      * Older versions of babel have a validation bug fixed by
      * https://github.com/babel/babel/pull/10917
@@ -2805,8 +2777,7 @@ function codegenArrayPattern(
     }
     return result;
   } else {
-    return createArrayPattern(
-      pattern.loc,
+    return t.arrayPattern(
       pattern.items.map(item => {
         if (item.kind === 'Hole') {
           return null;
@@ -2826,8 +2797,7 @@ function codegenLValue(
       return codegenArrayPattern(cx, pattern);
     }
     case 'ObjectPattern': {
-      return createObjectPattern(
-        pattern.loc,
+      return t.objectPattern(
         pattern.properties.map(property => {
           if (property.kind === 'ObjectProperty') {
             const key = codegenObjectPropertyKey(cx, property.key);
@@ -2946,7 +2916,7 @@ function convertIdentifier(identifier: Identifier): t.Identifier {
       suggestions: null,
     },
   );
-  return createIdentifier(identifier.loc, identifier.name.value);
+  return t.identifier(identifier.name.value);
 }
 
 function compareScopeDependency(

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

@@ -141,7 +141,6 @@ export function validateExhaustiveDependencies(
         reactive,
         startMemo.depsLoc,
         ErrorCategory.MemoDependencies,
-        'all',
       );
       if (diagnostic != null) {
         error.pushDiagnostic(diagnostic);
@@ -160,7 +159,7 @@ export function validateExhaustiveDependencies(
       onStartMemoize,
       onFinishMemoize,
       onEffect: (inferred, manual, manualMemoLoc) => {
-        if (env.config.validateExhaustiveEffectDependencies === 'off') {
+        if (env.config.validateExhaustiveEffectDependencies === false) {
           return;
         }
         if (DEBUG) {
@@ -196,17 +195,12 @@ export function validateExhaustiveDependencies(
             });
           }
         }
-        const effectReportMode =
-          typeof env.config.validateExhaustiveEffectDependencies === 'string'
-            ? env.config.validateExhaustiveEffectDependencies
-            : 'all';
         const diagnostic = validateDependencies(
           Array.from(inferred),
           manualDeps,
           reactive,
           manualMemoLoc,
           ErrorCategory.EffectExhaustiveDependencies,
-          effectReportMode,
         );
         if (diagnostic != null) {
           error.pushDiagnostic(diagnostic);
@@ -226,7 +220,6 @@ function validateDependencies(
   category:
     | ErrorCategory.MemoDependencies
     | ErrorCategory.EffectExhaustiveDependencies,
-  exhaustiveDepsReportMode: 'all' | 'missing-only' | 'extra-only',
 ): CompilerDiagnostic | null {
   // Sort dependencies by name and path, with shorter/non-optional paths first
   inferred.sort((a, b) => {
@@ -377,20 +370,9 @@ function validateDependencies(
     extra.push(dep);
   }
 
-  // Filter based on report mode
-  const filteredMissing =
-    exhaustiveDepsReportMode === 'extra-only' ? [] : missing;
-  const filteredExtra =
-    exhaustiveDepsReportMode === 'missing-only' ? [] : extra;
-
-  if (filteredMissing.length !== 0 || filteredExtra.length !== 0) {
+  if (missing.length !== 0 || extra.length !== 0) {
     let suggestion: CompilerSuggestion | null = null;
-    if (
-      manualMemoLoc != null &&
-      typeof manualMemoLoc !== 'symbol' &&
-      manualMemoLoc.start.index != null &&
-      manualMemoLoc.end.index != null
-    ) {
+    if (manualMemoLoc != null && typeof manualMemoLoc !== 'symbol') {
       suggestion = {
         description: 'Update dependencies',
         range: [manualMemoLoc.start.index, manualMemoLoc.end.index],
@@ -406,13 +388,8 @@ function validateDependencies(
           .join(', ')}]`,
       };
     }
-    const diagnostic = createDiagnostic(
-      category,
-      filteredMissing,
-      filteredExtra,
-      suggestion,
-    );
-    for (const dep of filteredMissing) {
+    const diagnostic = createDiagnostic(category, missing, extra, suggestion);
+    for (const dep of missing) {
       let reactiveStableValueHint = '';
       if (isStableType(dep.identifier)) {
         reactiveStableValueHint =
@@ -425,7 +402,7 @@ function validateDependencies(
         loc: dep.loc,
       });
     }
-    for (const dep of filteredExtra) {
+    for (const dep of extra) {
       if (dep.root.kind === 'Global') {
         diagnostic.withDetails({
           kind: 'error',

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

@@ -0,0 +1,59 @@
+/**
+ * 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 {CompilerDiagnostic, CompilerError} from '..';
+import {ErrorCategory} from '../CompilerError';
+import {HIRFunction} from '../HIR';
+import {getFunctionCallSignature} from '../Inference/InferMutationAliasingEffects';
+import {Result} from '../Utils/Result';
+
+/**
+ * Checks that known-impure functions are not called during render. Examples of invalid functions to
+ * call during render are `Math.random()` and `Date.now()`. Users may extend this set of
+ * impure functions via a module type provider and specifying functions with `impure: true`.
+ *
+ * TODO: add best-effort analysis of functions which are called during render. We have variations of
+ * this in several of our validation passes and should unify those analyses into a reusable helper
+ * and use it here.
+ */
+export function validateNoImpureFunctionsInRender(
+  fn: HIRFunction,
+): Result<void, CompilerError> {
+  const errors = new CompilerError();
+  for (const [, block] of fn.body.blocks) {
+    for (const instr of block.instructions) {
+      const value = instr.value;
+      if (value.kind === 'MethodCall' || value.kind == 'CallExpression') {
+        const callee =
+          value.kind === 'MethodCall' ? value.property : value.callee;
+        const signature = getFunctionCallSignature(
+          fn.env,
+          callee.identifier.type,
+        );
+        if (signature != null && signature.impure === true) {
+          errors.pushDiagnostic(
+            CompilerDiagnostic.create({
+              category: ErrorCategory.Purity,
+              reason: 'Cannot call impure function during render',
+              description:
+                (signature.canonicalName != null
+                  ? `\`${signature.canonicalName}\` is an impure function. `
+                  : '') +
+                'Calling an impure function can produce unstable results that update unpredictably when the component happens to re-render. (https://react.dev/reference/rules/components-and-hooks-must-be-pure#components-and-hooks-must-be-idempotent)',
+              suggestions: null,
+            }).withDetails({
+              kind: 'error',
+              loc: callee.loc,
+              message: 'Cannot call impure function',
+            }),
+          );
+        }
+      }
+    }
+  }
+  return errors.asResult();
+}

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

@@ -1,291 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import {CompilerDiagnostic, CompilerError, Effect} from '..';
-import {
-  areEqualSourceLocations,
-  HIRFunction,
-  IdentifierId,
-  isUseRefType,
-} from '../HIR';
-import {
-  eachInstructionLValue,
-  eachInstructionValueOperand,
-} from '../HIR/visitors';
-import {AliasingEffect} from '../Inference/AliasingEffects';
-import {createControlDominators} from '../Inference/ControlDominators';
-import {isMutable} from '../ReactiveScopes/InferReactiveScopeVariables';
-import {Err, Ok, Result} from '../Utils/Result';
-import {assertExhaustive, getOrInsertWith} from '../Utils/utils';
-
-type ImpureEffect = Extract<AliasingEffect, {kind: 'Impure'}>;
-type FunctionCache = Map<HIRFunction, Map<string, ImpuritySignature>>;
-type ImpuritySignature = {effects: Array<ImpureEffect>; error: CompilerError};
-
-export function validateNoImpureValuesInRender(
-  fn: HIRFunction,
-): Result<void, CompilerError> {
-  const impure = new Map<IdentifierId, ImpureEffect>();
-  const result = inferImpureValues(fn, impure, new Map());
-
-  if (result.error.hasAnyErrors()) {
-    return Err(result.error);
-  }
-  return Ok(undefined);
-}
-
-function inferFunctionExpressionMemo(
-  fn: HIRFunction,
-  impure: Map<IdentifierId, ImpureEffect>,
-  cache: FunctionCache,
-): ImpuritySignature {
-  const key = fn.context
-    .map(place => `${place.identifier.id}:${impure.has(place.identifier.id)}`)
-    .join(',');
-  return getOrInsertWith(
-    getOrInsertWith(cache, fn, () => new Map()),
-    key,
-    () => {
-      return inferImpureValues(fn, impure, cache);
-    },
-  );
-}
-
-function inferImpureValues(
-  fn: HIRFunction,
-  impure: Map<IdentifierId, ImpureEffect>,
-  cache: FunctionCache,
-): ImpuritySignature {
-  const getBlockControl = createControlDominators(fn, place => {
-    return impure.has(place.identifier.id);
-  });
-
-  let hasChanges = false;
-  do {
-    hasChanges = false;
-
-    for (const block of fn.body.blocks.values()) {
-      const controlPlace = getBlockControl(block.id);
-      const controlImpureEffect =
-        controlPlace != null ? impure.get(controlPlace.identifier.id) : null;
-
-      for (const phi of block.phis) {
-        if (impure.has(phi.place.identifier.id)) {
-          // Already marked impure on a previous pass
-          continue;
-        }
-        let impureEffect = null;
-        for (const [, operand] of phi.operands) {
-          const operandEffect = impure.get(operand.identifier.id);
-          if (operandEffect != null) {
-            impureEffect = operandEffect;
-            break;
-          }
-        }
-        if (impureEffect != null) {
-          impure.set(phi.place.identifier.id, impureEffect);
-          hasChanges = true;
-        } else {
-          for (const [pred] of phi.operands) {
-            const predControl = getBlockControl(pred);
-            if (predControl != null) {
-              const predEffect = impure.get(predControl.identifier.id);
-              if (predEffect != null) {
-                impure.set(phi.place.identifier.id, predEffect);
-                hasChanges = true;
-                break;
-              }
-            }
-          }
-        }
-      }
-
-      for (const instr of block.instructions) {
-        let impureEffect: ImpureEffect | undefined = instr.effects?.find(
-          (effect: AliasingEffect): effect is ImpureEffect =>
-            effect.kind === 'Impure',
-        );
-
-        if (
-          impureEffect == null &&
-          (instr.value.kind === 'FunctionExpression' ||
-            instr.value.kind === 'ObjectMethod')
-        ) {
-          impureEffect = instr.value.loweredFunc.func.aliasingEffects?.find(
-            (effect: AliasingEffect): effect is ImpureEffect =>
-              effect.kind === 'Impure',
-          );
-          if (impureEffect == null) {
-            const result = inferFunctionExpressionMemo(
-              instr.value.loweredFunc.func,
-              impure,
-              cache,
-            );
-            if (!result.error.hasAnyErrors()) {
-              impureEffect = result.effects[0];
-            }
-          }
-        }
-
-        if (impureEffect == null) {
-          for (const operand of eachInstructionValueOperand(instr.value)) {
-            const operandEffect = impure.get(operand.identifier.id);
-            if (operandEffect != null) {
-              impureEffect = operandEffect;
-              break;
-            }
-          }
-        }
-
-        if (impureEffect != null) {
-          for (const lvalue of eachInstructionLValue(instr)) {
-            if (isUseRefType(lvalue.identifier)) {
-              continue;
-            }
-            if (!impure.has(lvalue.identifier.id)) {
-              impure.set(lvalue.identifier.id, impureEffect);
-              hasChanges = true;
-            }
-          }
-        }
-        if (impureEffect != null || controlImpureEffect != null) {
-          for (const operand of eachInstructionValueOperand(instr.value)) {
-            switch (operand.effect) {
-              case Effect.Capture:
-              case Effect.Store:
-              case Effect.ConditionallyMutate:
-              case Effect.ConditionallyMutateIterator:
-              case Effect.Mutate: {
-                if (
-                  !impure.has(operand.identifier.id) &&
-                  isMutable(instr, operand)
-                ) {
-                  impure.set(
-                    operand.identifier.id,
-                    (impureEffect ?? controlImpureEffect)!,
-                  );
-                  hasChanges = true;
-                }
-                break;
-              }
-              case Effect.Freeze:
-              case Effect.Read: {
-                // no-op
-                break;
-              }
-              case Effect.Unknown: {
-                CompilerError.invariant(false, {
-                  reason: 'Unexpected unknown effect',
-                  description: null,
-                  details: [
-                    {
-                      kind: 'error',
-                      loc: operand.loc,
-                      message: null,
-                    },
-                  ],
-                  suggestions: null,
-                });
-              }
-              default: {
-                assertExhaustive(
-                  operand.effect,
-                  `Unexpected effect kind \`${operand.effect}\``,
-                );
-              }
-            }
-          }
-        }
-        if (impureEffect == null) {
-          const lvalueEffect = impure.get(instr.lvalue.identifier.id)!;
-          if (lvalueEffect != null) {
-            for (const operand of eachInstructionValueOperand(instr.value)) {
-              if (
-                isMutable(instr, operand) &&
-                !impure.has(operand.identifier.id)
-              ) {
-                impure.set(operand.identifier.id, lvalueEffect);
-                hasChanges = true;
-              }
-            }
-          }
-        }
-      }
-
-      if (block.terminal.kind === 'return') {
-        const terminalEffect = impure.get(block.terminal.value.identifier.id);
-        if (terminalEffect != null && !impure.has(fn.returns.identifier.id)) {
-          impure.set(fn.returns.identifier.id, terminalEffect);
-          hasChanges = true;
-        }
-      }
-    }
-  } while (hasChanges);
-
-  const error = new CompilerError();
-  for (const block of fn.body.blocks.values()) {
-    for (const instr of block.instructions) {
-      const value = instr.value;
-      if (
-        value.kind === 'FunctionExpression' ||
-        value.kind === 'ObjectMethod'
-      ) {
-        const result = inferFunctionExpressionMemo(
-          value.loweredFunc.func,
-          impure,
-          cache,
-        );
-        if (result.error.hasAnyErrors()) {
-          error.merge(result.error);
-        }
-      }
-      for (const effect of instr.effects ?? []) {
-        if (
-          effect.kind !== 'Render' ||
-          !impure.has(effect.place.identifier.id)
-        ) {
-          continue;
-        }
-        const impureEffect = impure.get(effect.place.identifier.id)!;
-        const diagnostic = CompilerDiagnostic.create({
-          category: impureEffect.category,
-          reason: impureEffect.reason,
-          description: impureEffect.description,
-        }).withDetails({
-          kind: 'error',
-          loc: effect.place.loc,
-          message: impureEffect.usageMessage,
-        });
-        if (!areEqualSourceLocations(effect.place.loc, impureEffect.into.loc)) {
-          diagnostic.withDetails({
-            kind: 'error',
-            loc: impureEffect.into.loc,
-            message: impureEffect.sourceMessage,
-          });
-        }
-        error.pushDiagnostic(diagnostic);
-      }
-    }
-  }
-  const impureEffects: Array<ImpureEffect> = [];
-  for (const param of [...fn.context, ...fn.params, fn.returns]) {
-    const place = param.kind === 'Identifier' ? param : param.place;
-    const impureEffect = impure.get(place.identifier.id);
-    if (impureEffect != null) {
-      impureEffects.push({
-        kind: 'Impure',
-        into: {...place},
-        category: impureEffect.category,
-        reason: impureEffect.reason,
-        description: impureEffect.description,
-        sourceMessage: impureEffect.sourceMessage,
-        usageMessage: impureEffect.usageMessage,
-      });
-    }
-  }
-  return {effects: impureEffects, error};
-}

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

@@ -511,7 +511,7 @@ function validateNoRefAccessInRenderImpl(
                   CompilerDiagnostic.create({
                     category: ErrorCategory.Refs,
                     reason: 'Cannot access refs during render',
-                    description: REF_ERROR_DESCRIPTION,
+                    description: ERROR_DESCRIPTION,
                   }).withDetails({
                     kind: 'error',
                     loc: callee.loc,
@@ -666,7 +666,7 @@ function validateNoRefAccessInRenderImpl(
                   CompilerDiagnostic.create({
                     category: ErrorCategory.Refs,
                     reason: 'Cannot access refs during render',
-                    description: REF_ERROR_DESCRIPTION,
+                    description: ERROR_DESCRIPTION,
                   })
                     .withDetails({
                       kind: 'error',
@@ -814,7 +814,7 @@ function guardCheck(errors: CompilerError, operand: Place, env: Env): void {
       CompilerDiagnostic.create({
         category: ErrorCategory.Refs,
         reason: 'Cannot access refs during render',
-        description: REF_ERROR_DESCRIPTION,
+        description: ERROR_DESCRIPTION,
       }).withDetails({
         kind: 'error',
         loc: operand.loc,
@@ -838,7 +838,7 @@ function validateNoRefValueAccess(
       CompilerDiagnostic.create({
         category: ErrorCategory.Refs,
         reason: 'Cannot access refs during render',
-        description: REF_ERROR_DESCRIPTION,
+        description: ERROR_DESCRIPTION,
       }).withDetails({
         kind: 'error',
         loc: (type.kind === 'RefValue' && type.loc) || operand.loc,
@@ -864,7 +864,7 @@ function validateNoRefPassedToFunction(
       CompilerDiagnostic.create({
         category: ErrorCategory.Refs,
         reason: 'Cannot access refs during render',
-        description: REF_ERROR_DESCRIPTION,
+        description: ERROR_DESCRIPTION,
       }).withDetails({
         kind: 'error',
         loc: (type.kind === 'RefValue' && type.loc) || loc,
@@ -886,7 +886,7 @@ function validateNoRefUpdate(
       CompilerDiagnostic.create({
         category: ErrorCategory.Refs,
         reason: 'Cannot access refs during render',
-        description: REF_ERROR_DESCRIPTION,
+        description: ERROR_DESCRIPTION,
       }).withDetails({
         kind: 'error',
         loc: (type.kind === 'RefValue' && type.loc) || loc,
@@ -907,7 +907,7 @@ function validateNoDirectRefValueAccess(
       CompilerDiagnostic.create({
         category: ErrorCategory.Refs,
         reason: 'Cannot access refs during render',
-        description: REF_ERROR_DESCRIPTION,
+        description: ERROR_DESCRIPTION,
       }).withDetails({
         kind: 'error',
         loc: type.loc ?? operand.loc,
@@ -917,7 +917,7 @@ function validateNoDirectRefValueAccess(
   }
 }
 
-export const REF_ERROR_DESCRIPTION =
+const ERROR_DESCRIPTION =
   'React refs are values that are not needed for rendering. Refs should only be accessed ' +
   'outside of render, such as in event handlers or effects. ' +
   'Accessing a ref value (the `current` property) during render can cause your component ' +

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

@@ -202,10 +202,10 @@ function getSetStateCall(
     );
   };
 
-  const isRefControlledBlock: (id: BlockId) => Place | null =
+  const isRefControlledBlock: (id: BlockId) => boolean =
     enableAllowSetStateFromRefsInEffects
       ? createControlDominators(fn, place => isDerivedFromRef(place))
-      : (): Place | null => null;
+      : (): boolean => false;
 
   for (const [, block] of fn.body.blocks) {
     if (enableAllowSetStateFromRefsInEffects) {
@@ -224,7 +224,7 @@ function getSetStateCall(
           refDerivedValues.add(phi.place.identifier.id);
         } else {
           for (const [pred] of phi.operands) {
-            if (isRefControlledBlock(pred) != null) {
+            if (isRefControlledBlock(pred)) {
               refDerivedValues.add(phi.place.identifier.id);
               break;
             }
@@ -337,7 +337,7 @@ function getSetStateCall(
                  * be needed when initial layout measurements from refs need to be stored in state.
                  */
                 return null;
-              } else if (isRefControlledBlock(block.id) != null) {
+              } else if (isRefControlledBlock(block.id)) {
                 continue;
               }
             }

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

@@ -27,11 +27,7 @@ import {Result} from '../Utils/Result';
 
 /**
  * Some common node types that are important for coverage tracking.
- * Based on istanbul-lib-instrument + some other common nodes we expect to be present in the generated AST.
- *
- * Note: For VariableDeclaration, VariableDeclarator, and Identifier, we enforce stricter validation
- * that requires both the source location AND node type to match in the generated AST. This ensures
- * that variable declarations maintain their structural integrity through compilation.
+ * Based on istanbul-lib-instrument
  */
 const IMPORTANT_INSTRUMENTED_TYPES = new Set([
   'ArrowFunctionExpression',
@@ -58,14 +54,6 @@ const IMPORTANT_INSTRUMENTED_TYPES = new Set([
   'LabeledStatement',
   'ConditionalExpression',
   'LogicalExpression',
-
-  /**
-   * Note: these aren't important for coverage tracking,
-   * but we still want to track them to ensure we aren't regressing them when
-   * we fix the source location tracking for other nodes.
-   */
-  'VariableDeclaration',
-  'Identifier',
 ]);
 
 /**
@@ -126,13 +114,10 @@ export function validateSourceLocations(
 ): Result<void, CompilerError> {
   const errors = new CompilerError();
 
-  /*
-   * Step 1: Collect important locations from the original source
-   * Note: Multiple node types can share the same location (e.g. VariableDeclarator and Identifier)
-   */
+  // Step 1: Collect important locations from the original source
   const importantOriginalLocations = new Map<
     string,
-    {loc: t.SourceLocation; nodeTypes: Set<string>}
+    {loc: t.SourceLocation; nodeType: string}
   >();
 
   func.traverse({
@@ -152,31 +137,20 @@ export function validateSourceLocations(
       // Collect the location if it exists
       if (node.loc) {
         const key = locationKey(node.loc);
-        const existing = importantOriginalLocations.get(key);
-        if (existing) {
-          existing.nodeTypes.add(node.type);
-        } else {
-          importantOriginalLocations.set(key, {
-            loc: node.loc,
-            nodeTypes: new Set([node.type]),
-          });
-        }
+        importantOriginalLocations.set(key, {
+          loc: node.loc,
+          nodeType: node.type,
+        });
       }
     },
   });
 
-  // Step 2: Collect all locations from the generated AST with their node types
-  const generatedLocations = new Map<string, Set<string>>();
+  // Step 2: Collect all locations from the generated AST
+  const generatedLocations = new Set<string>();
 
   function collectGeneratedLocations(node: t.Node): void {
     if (node.loc) {
-      const key = locationKey(node.loc);
-      const nodeTypes = generatedLocations.get(key);
-      if (nodeTypes) {
-        nodeTypes.add(node.type);
-      } else {
-        generatedLocations.set(key, new Set([node.type]));
-      }
+      generatedLocations.add(locationKey(node.loc));
     }
 
     // Use Babel's VISITOR_KEYS to traverse only actual node properties
@@ -209,86 +183,22 @@ export function validateSourceLocations(
     collectGeneratedLocations(outlined.fn.body);
   }
 
-  /*
-   * Step 3: Validate that all important locations are preserved
-   * For certain node types, also validate that the node type matches
-   */
-  const strictNodeTypes = new Set([
-    'VariableDeclaration',
-    'VariableDeclarator',
-    'Identifier',
-  ]);
-
-  const reportMissingLocation = (
-    loc: t.SourceLocation,
-    nodeType: string,
-  ): void => {
-    errors.pushDiagnostic(
-      CompilerDiagnostic.create({
-        category: ErrorCategory.Todo,
-        reason: 'Important source location missing in generated code',
-        description:
-          `Source location for ${nodeType} is missing in the generated output. This can cause coverage instrumentation ` +
-          `to fail to track this code properly, resulting in inaccurate coverage reports.`,
-      }).withDetails({
-        kind: 'error',
-        loc,
-        message: null,
-      }),
-    );
-  };
-
-  const reportWrongNodeType = (
-    loc: t.SourceLocation,
-    expectedType: string,
-    actualTypes: Set<string>,
-  ): void => {
-    errors.pushDiagnostic(
-      CompilerDiagnostic.create({
-        category: ErrorCategory.Todo,
-        reason:
-          'Important source location has wrong node type in generated code',
-        description:
-          `Source location for ${expectedType} exists in the generated output but with wrong node type(s): ${Array.from(actualTypes).join(', ')}. ` +
-          `This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports.`,
-      }).withDetails({
-        kind: 'error',
-        loc,
-        message: null,
-      }),
-    );
-  };
-
-  for (const [key, {loc, nodeTypes}] of importantOriginalLocations) {
-    const generatedNodeTypes = generatedLocations.get(key);
-
-    if (!generatedNodeTypes) {
-      // Location is completely missing
-      reportMissingLocation(loc, Array.from(nodeTypes).join(', '));
-    } else {
-      // Location exists, check each node type
-      for (const nodeType of nodeTypes) {
-        if (
-          strictNodeTypes.has(nodeType) &&
-          !generatedNodeTypes.has(nodeType)
-        ) {
-          /*
-           * For strict node types, the specific node type must be present
-           * Check if any generated node type is also an important original node type
-           */
-          const hasValidNodeType = Array.from(generatedNodeTypes).some(
-            genType => nodeTypes.has(genType),
-          );
-
-          if (hasValidNodeType) {
-            // At least one generated node type is valid (also in original), so this is just missing
-            reportMissingLocation(loc, nodeType);
-          } else {
-            // None of the generated node types are in original - this is wrong node type
-            reportWrongNodeType(loc, nodeType, generatedNodeTypes);
-          }
-        }
-      }
+  // Step 3: Validate that all important locations are preserved
+  for (const [key, {loc, nodeType}] of importantOriginalLocations) {
+    if (!generatedLocations.has(key)) {
+      errors.pushDiagnostic(
+        CompilerDiagnostic.create({
+          category: ErrorCategory.Todo,
+          reason: 'Important source location missing in generated code',
+          description:
+            `Source location for ${nodeType} is missing in the generated output. This can cause coverage instrumentation ` +
+            `to fail to track this code properly, resulting in inaccurate coverage reports.`,
+        }).withDetails({
+          kind: 'error',
+          loc,
+          message: null,
+        }),
+      );
     }
   }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver-and-mutate.expect.md

@@ -35,8 +35,10 @@ function Component() {
   let t0;
   if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
     const a = makeObject_Primitives();
+
     const x = [];
     x.push(a);
+
     mutate(x);
     t0 = [x, a];
     $[0] = t0;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver.expect.md

@@ -33,6 +33,7 @@ function Component() {
   if ($[1] === Symbol.for("react.memo_cache_sentinel")) {
     const x = [];
     x.push(a);
+
     t1 = [x, a];
     $[1] = t1;
   } else {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/aliased-nested-scope-fn-expr.expect.md

@@ -85,10 +85,14 @@ function Component(t0) {
   let t1;
   if ($[0] !== prop) {
     const obj = shallowCopy(prop);
+
     const aliasedObj = identity(obj);
+
     const getId = () => obj.id;
+
     mutate(aliasedObj);
     setPropertyByKey(aliasedObj, "id", prop.id + 1);
+
     t1 = <Stringify getId={getId} shouldInvokeFns={true} />;
     $[0] = prop;
     $[1] = t1;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/aliased-nested-scope-truncated-dep.expect.md

@@ -181,9 +181,12 @@ function Component(t0) {
   if ($[0] !== prop) {
     const obj = shallowCopy(prop);
     const aliasedObj = identity(obj);
+
     const id = [obj.id];
+
     mutate(aliasedObj);
     setPropertyByKey(aliasedObj, "id", prop.id + 1);
+
     t1 = <Stringify id={id} />;
     $[0] = prop;
     $[1] = t1;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/align-scopes-within-nested-valueblock-in-array.expect.md

@@ -54,6 +54,7 @@ function Foo(t0) {
   let t1;
   if ($[0] !== cond1 || $[1] !== cond2) {
     const arr = makeArray({ a: 2 }, 2, []);
+
     t1 = cond1 ? (
       <>
         <div>{identity("foo")}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-assigning-ref-accessing-function-to-object-property-if-not-mutated.expect.md

@@ -0,0 +1,52 @@
+
+## Input
+
+```javascript
+import {useRef} from 'react';
+import {Stringify} from 'shared-runtime';
+
+function Component(props) {
+  const ref = useRef(props.value);
+  const object = {};
+  object.foo = () => ref.current;
+  return <Stringify object={object} shouldInvokeFns={true} />;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{value: 42}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+import { useRef } from "react";
+import { Stringify } from "shared-runtime";
+
+function Component(props) {
+  const $ = _c(1);
+  const ref = useRef(props.value);
+  let t0;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    const object = {};
+    object.foo = () => ref.current;
+    t0 = <Stringify object={object} shouldInvokeFns={true} />;
+    $[0] = t0;
+  } else {
+    t0 = $[0];
+  }
+  return t0;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ value: 42 }],
+};
+
+```
+      
+### Eval output
+(kind: ok) <div>{"object":{"foo":{"kind":"Function","result":42}},"shouldInvokeFns":true}</div>

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-mutating-ref-in-callback-passed-to-jsx-indirect.expect.md

@@ -49,6 +49,7 @@ function Component() {
         ref.current = "";
       }
     };
+
     t0 = () => {
       setRef();
     };

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-mutating-ref-property-in-callback-passed-to-jsx-indirect.expect.md

@@ -49,6 +49,7 @@ function Component() {
         ref.current.value = "";
       }
     };
+
     t0 = () => {
       setRef();
     };

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-ref-access-in-event-handler-wrapper.expect.md

@@ -74,6 +74,7 @@ function Component() {
         console.log(ref.current.value);
       }
     };
+
     t0 = (
       <>
         <input ref={ref} />

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-ref-type-cast-in-render.expect.md

@@ -36,6 +36,7 @@ function useArrayOfRef() {
     const callback = (value) => {
       ref.current = value;
     };
+
     t0 = [callback];
     $[0] = t0;
   } else {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-at-closure.expect.md

@@ -35,6 +35,7 @@ function Component(props) {
       const arr = [...bar(props)];
       return arr.at(x);
     };
+
     t1 = fn();
     $[2] = props;
     $[3] = x;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-spread-mutable-iterator.expect.md

@@ -61,6 +61,7 @@ function useBar(t0) {
   if ($[0] !== arg) {
     const s = new Set([1, 5, 4]);
     const mutableIterator = s.values();
+
     t1 = [arg, ...mutableIterator];
     $[0] = arg;
     $[1] = t1;

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

@@ -28,6 +28,7 @@ function Component(props) {
     const a = [];
     const b = {};
     foo(a, b);
+
     foo(b);
     t0 = <div a={a} b={b} />;
     $[0] = t0;

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

@@ -45,6 +45,7 @@ function useKeyCommand() {
       const nextPosition = direction === "left" ? addOne(position) : position;
       currentPosition.current = nextPosition;
     };
+
     const moveLeft = { handler: handleKey("left") };
     const moveRight = { handler: handleKey("right") };
     t0 = [moveLeft, moveRight];

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/capturing-func-mutate.expect.md

@@ -45,6 +45,7 @@ function Component(t0) {
       z.a = 2;
       mutate(y.b);
     };
+
     x();
     t1 = [y, z];
     $[0] = a;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/codegen-emit-make-read-only.expect.md

@@ -29,6 +29,7 @@ function MyComponentName(props) {
     const x = {};
     foo(x, props.a);
     foo(x, props.b);
+
     y = [];
     y.push(x);
     $[0] = props.a;

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

@@ -34,6 +34,7 @@ function useTest() {
   let t0;
   if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
     let w = {};
+
     const t1 = (w = 42);
     const t2 = w;
 

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

@@ -34,6 +34,7 @@ function useTest() {
   let t0;
   if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
     const w = {};
+
     const t1 = (w.x = 42);
     const t2 = w.x;
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/conditional-on-mutable.expect.md

@@ -44,9 +44,11 @@ function ComponentA(props) {
     if (b) {
       a.push(props.p0);
     }
+
     if (props.p1) {
       b.push(props.p2);
     }
+
     t0 = <Foo a={a} b={b} />;
     $[0] = props.p0;
     $[1] = props.p1;
@@ -67,9 +69,11 @@ function ComponentB(props) {
     if (mayMutate(b)) {
       a.push(props.p0);
     }
+
     if (props.p1) {
       b.push(props.p2);
     }
+
     t0 = <Foo a={a} b={b} />;
     $[0] = props.p0;
     $[1] = props.p1;

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

@@ -28,6 +28,7 @@ function Component(props) {
     const a = [];
     const b = {};
     new Foo(a, b);
+
     new Foo(b);
     t0 = <div a={a} b={b} />;
     $[0] = t0;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/context-variable-reassigned-outside-of-lambda.expect.md

@@ -34,6 +34,7 @@ function Component(props) {
     const callback = () => {
       console.log(x);
     };
+
     x = {};
     t0 = <Stringify callback={callback} shouldInvokeFns={true} />;
     $[0] = t0;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/destructuring-mixed-scope-and-local-variables-with-default.expect.md

@@ -75,6 +75,7 @@ function Component(props) {
   let t0;
   if ($[0] !== post) {
     const allUrls = [];
+
     const { media: t1, comments: t2, urls: t3 } = post;
     const media = t1 === undefined ? null : t1;
     let t4;
@@ -101,6 +102,7 @@ function Component(props) {
         if (!comments.length) {
           return;
         }
+
         console.log(comments.length);
       };
       $[6] = comments.length;
@@ -109,6 +111,7 @@ function Component(props) {
       t6 = $[7];
     }
     const onClick = t6;
+
     allUrls.push(...urls);
     t0 = <Stringify media={media} allUrls={allUrls} onClick={onClick} />;
     $[0] = post;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/destructuring-mixed-scope-declarations-and-locals.expect.md

@@ -53,6 +53,7 @@ function Component(props) {
   let t0;
   if ($[0] !== post) {
     const allUrls = [];
+
     const { media, comments, urls } = post;
     let t1;
     if ($[2] !== comments.length) {
@@ -60,6 +61,7 @@ function Component(props) {
         if (!comments.length) {
           return;
         }
+
         console.log(comments.length);
       };
       $[2] = comments.length;
@@ -68,6 +70,7 @@ function Component(props) {
       t1 = $[3];
     }
     const onClick = t1;
+
     allUrls.push(...urls);
     t0 = <Media media={media} onClick={onClick} />;
     $[0] = post;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/dont-merge-if-dep-is-inner-declaration-of-previous-scope.expect.md

@@ -57,6 +57,7 @@ function Component(t0) {
   let y;
   if ($[0] !== a || $[1] !== b || $[2] !== c) {
     x = [];
+
     if (a) {
       let t1;
       if ($[5] !== b) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-conditionally-in-effect.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({value, enabled}) {
@@ -29,21 +29,43 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState } from "react";
 
-function Component({ value, enabled }) {
+function Component(t0) {
+  const $ = _c(6);
+  const { value, enabled } = t0;
   const [localValue, setLocalValue] = useState("");
+  let t1;
+  let t2;
+  if ($[0] !== enabled || $[1] !== value) {
+    t1 = () => {
+      if (enabled) {
+        setLocalValue(value);
+      } else {
+        setLocalValue("disabled");
+      }
+    };
 
-  useEffect(() => {
-    if (enabled) {
-      setLocalValue(value);
-    } else {
-      setLocalValue("disabled");
-    }
-  }, [value, enabled]);
-
-  return <div>{localValue}</div>;
+    t2 = [value, enabled];
+    $[0] = enabled;
+    $[1] = value;
+    $[2] = t1;
+    $[3] = t2;
+  } else {
+    t1 = $[2];
+    t2 = $[3];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[4] !== localValue) {
+    t3 = <div>{localValue}</div>;
+    $[4] = localValue;
+    $[5] = t3;
+  } else {
+    t3 = $[5];
+  }
+  return t3;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -56,8 +78,8 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [value]\n\nData Flow Tree:\n└── value (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":9,"column":6,"index":263},"end":{"line":9,"column":19,"index":276},"filename":"derived-state-conditionally-in-effect.ts","identifierName":"setLocalValue"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":126},"end":{"line":16,"column":1,"index":397},"filename":"derived-state-conditionally-in-effect.ts"},"fnName":"Component","memoSlots":6,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [value]\n\nData Flow Tree:\n└── value (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":9,"column":6,"index":244},"end":{"line":9,"column":19,"index":257},"filename":"derived-state-conditionally-in-effect.ts","identifierName":"setLocalValue"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":16,"column":1,"index":378},"filename":"derived-state-conditionally-in-effect.ts"},"fnName":"Component","memoSlots":6,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-conditionally-in-effect.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({value, enabled}) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-default-props.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 export default function Component({input = 'empty'}) {
@@ -26,18 +26,38 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState } from "react";
 
-export default function Component({ input = "empty" }) {
+export default function Component(t0) {
+  const $ = _c(5);
+  const { input: t1 } = t0;
+  const input = t1 === undefined ? "empty" : t1;
   const [currInput, setCurrInput] = useState(input);
-  const localConst = "local const";
-
-  useEffect(() => {
-    setCurrInput(input + localConst);
-  }, [input, localConst]);
-
-  return <div>{currInput}</div>;
+  let t2;
+  let t3;
+  if ($[0] !== input) {
+    t2 = () => {
+      setCurrInput(input + "local const");
+    };
+    t3 = [input, "local const"];
+    $[0] = input;
+    $[1] = t2;
+    $[2] = t3;
+  } else {
+    t2 = $[1];
+    t3 = $[2];
+  }
+  useEffect(t2, t3);
+  let t4;
+  if ($[3] !== currInput) {
+    t4 = <div>{currInput}</div>;
+    $[3] = currInput;
+    $[4] = t4;
+  } else {
+    t4 = $[4];
+  }
+  return t4;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -50,8 +70,8 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [input]\n\nData Flow Tree:\n└── input (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":9,"column":4,"index":295},"end":{"line":9,"column":16,"index":307},"filename":"derived-state-from-default-props.ts","identifierName":"setCurrInput"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":141},"end":{"line":13,"column":1,"index":391},"filename":"derived-state-from-default-props.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [input]\n\nData Flow Tree:\n└── input (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":9,"column":4,"index":276},"end":{"line":9,"column":16,"index":288},"filename":"derived-state-from-default-props.ts","identifierName":"setCurrInput"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":122},"end":{"line":13,"column":1,"index":372},"filename":"derived-state-from-default-props.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-default-props.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 export default function Component({input = 'empty'}) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-local-state-in-effect.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
 import {useEffect, useState} from 'react';
 
@@ -23,20 +23,45 @@ function Component({shouldChange}) {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
 import { useEffect, useState } from "react";
 
-function Component({ shouldChange }) {
+function Component(t0) {
+  const $ = _c(7);
+  const { shouldChange } = t0;
   const [count, setCount] = useState(0);
-
-  useEffect(() => {
-    if (shouldChange) {
-      setCount(count + 1);
-    }
-  }, [count]);
-
-  return <div>{count}</div>;
+  let t1;
+  if ($[0] !== count || $[1] !== shouldChange) {
+    t1 = () => {
+      if (shouldChange) {
+        setCount(count + 1);
+      }
+    };
+    $[0] = count;
+    $[1] = shouldChange;
+    $[2] = t1;
+  } else {
+    t1 = $[2];
+  }
+  let t2;
+  if ($[3] !== count) {
+    t2 = [count];
+    $[3] = count;
+    $[4] = t2;
+  } else {
+    t2 = $[4];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[5] !== count) {
+    t3 = <div>{count}</div>;
+    $[5] = count;
+    $[6] = t3;
+  } else {
+    t3 = $[6];
+  }
+  return t3;
 }
 
 ```
@@ -44,8 +69,8 @@ function Component({ shouldChange }) {
 ## Logs
 
 ```
-{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nState: [count]\n\nData Flow Tree:\n└── count (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":10,"column":6,"index":256},"end":{"line":10,"column":14,"index":264},"filename":"derived-state-from-local-state-in-effect.ts","identifierName":"setCount"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":5,"column":0,"index":127},"end":{"line":15,"column":1,"index":329},"filename":"derived-state-from-local-state-in-effect.ts"},"fnName":"Component","memoSlots":7,"memoBlocks":3,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nState: [count]\n\nData Flow Tree:\n└── count (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":10,"column":6,"index":237},"end":{"line":10,"column":14,"index":245},"filename":"derived-state-from-local-state-in-effect.ts","identifierName":"setCount"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":5,"column":0,"index":108},"end":{"line":15,"column":1,"index":310},"filename":"derived-state-from-local-state-in-effect.ts"},"fnName":"Component","memoSlots":7,"memoBlocks":3,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-local-state-in-effect.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
 import {useEffect, useState} from 'react';
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-local-state-and-component-scope.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({firstName}) {
@@ -33,25 +33,68 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState } from "react";
 
-function Component({ firstName }) {
+function Component(t0) {
+  const $ = _c(12);
+  const { firstName } = t0;
   const [lastName, setLastName] = useState("Doe");
   const [fullName, setFullName] = useState("John");
-
-  const middleName = "D.";
-
-  useEffect(() => {
-    setFullName(firstName + " " + middleName + " " + lastName);
-  }, [firstName, middleName, lastName]);
-
-  return (
-    <div>
-      <input value={lastName} onChange={(e) => setLastName(e.target.value)} />
-      <div>{fullName}</div>
-    </div>
-  );
+  let t1;
+  let t2;
+  if ($[0] !== firstName || $[1] !== lastName) {
+    t1 = () => {
+      setFullName(firstName + " " + "D." + " " + lastName);
+    };
+    t2 = [firstName, "D.", lastName];
+    $[0] = firstName;
+    $[1] = lastName;
+    $[2] = t1;
+    $[3] = t2;
+  } else {
+    t1 = $[2];
+    t2 = $[3];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[4] === Symbol.for("react.memo_cache_sentinel")) {
+    t3 = (e) => setLastName(e.target.value);
+    $[4] = t3;
+  } else {
+    t3 = $[4];
+  }
+  let t4;
+  if ($[5] !== lastName) {
+    t4 = <input value={lastName} onChange={t3} />;
+    $[5] = lastName;
+    $[6] = t4;
+  } else {
+    t4 = $[6];
+  }
+  let t5;
+  if ($[7] !== fullName) {
+    t5 = <div>{fullName}</div>;
+    $[7] = fullName;
+    $[8] = t5;
+  } else {
+    t5 = $[8];
+  }
+  let t6;
+  if ($[9] !== t4 || $[10] !== t5) {
+    t6 = (
+      <div>
+        {t4}
+        {t5}
+      </div>
+    );
+    $[9] = t4;
+    $[10] = t5;
+    $[11] = t6;
+  } else {
+    t6 = $[11];
+  }
+  return t6;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -64,8 +107,8 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [firstName]\nState: [lastName]\n\nData Flow Tree:\n├── firstName (Prop)\n└── lastName (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":11,"column":4,"index":316},"end":{"line":11,"column":15,"index":327},"filename":"derived-state-from-prop-local-state-and-component-scope.ts","identifierName":"setFullName"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":126},"end":{"line":20,"column":1,"index":561},"filename":"derived-state-from-prop-local-state-and-component-scope.ts"},"fnName":"Component","memoSlots":12,"memoBlocks":5,"memoValues":6,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [firstName]\nState: [lastName]\n\nData Flow Tree:\n├── firstName (Prop)\n└── lastName (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":11,"column":4,"index":297},"end":{"line":11,"column":15,"index":308},"filename":"derived-state-from-prop-local-state-and-component-scope.ts","identifierName":"setFullName"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":20,"column":1,"index":542},"filename":"derived-state-from-prop-local-state-and-component-scope.ts"},"fnName":"Component","memoSlots":12,"memoBlocks":5,"memoValues":6,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-local-state-and-component-scope.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({firstName}) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-call-outside-effect-no-error.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({initialName}) {
@@ -29,21 +29,48 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState } from "react";
 
-function Component({ initialName }) {
+function Component(t0) {
+  const $ = _c(6);
+  const { initialName } = t0;
   const [name, setName] = useState("");
-
-  useEffect(() => {
-    setName(initialName);
-  }, [initialName]);
-
-  return (
-    <div>
-      <input value={name} onChange={(e) => setName(e.target.value)} />
-    </div>
-  );
+  let t1;
+  let t2;
+  if ($[0] !== initialName) {
+    t1 = () => {
+      setName(initialName);
+    };
+    t2 = [initialName];
+    $[0] = initialName;
+    $[1] = t1;
+    $[2] = t2;
+  } else {
+    t1 = $[1];
+    t2 = $[2];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[3] === Symbol.for("react.memo_cache_sentinel")) {
+    t3 = (e) => setName(e.target.value);
+    $[3] = t3;
+  } else {
+    t3 = $[3];
+  }
+  let t4;
+  if ($[4] !== name) {
+    t4 = (
+      <div>
+        <input value={name} onChange={t3} />
+      </div>
+    );
+    $[4] = name;
+    $[5] = t4;
+  } else {
+    t4 = $[5];
+  }
+  return t4;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -56,7 +83,7 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":126},"end":{"line":16,"column":1,"index":378},"filename":"derived-state-from-prop-setter-call-outside-effect-no-error.ts"},"fnName":"Component","memoSlots":6,"memoBlocks":3,"memoValues":4,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":16,"column":1,"index":359},"filename":"derived-state-from-prop-setter-call-outside-effect-no-error.ts"},"fnName":"Component","memoSlots":6,"memoBlocks":3,"memoValues":4,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-call-outside-effect-no-error.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({initialName}) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-ternary.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp
 
 function Component({value}) {
   const [checked, setChecked] = useState('');
@@ -19,16 +19,36 @@ function Component({value}) {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp
 
-function Component({ value }) {
+function Component(t0) {
+  const $ = _c(5);
+  const { value } = t0;
   const [checked, setChecked] = useState("");
-
-  useEffect(() => {
-    setChecked(value === "" ? [] : value.split(","));
-  }, [value]);
-
-  return <div>{checked}</div>;
+  let t1;
+  let t2;
+  if ($[0] !== value) {
+    t1 = () => {
+      setChecked(value === "" ? [] : value.split(","));
+    };
+    t2 = [value];
+    $[0] = value;
+    $[1] = t1;
+    $[2] = t2;
+  } else {
+    t1 = $[1];
+    t2 = $[2];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[3] !== checked) {
+    t3 = <div>{checked}</div>;
+    $[3] = checked;
+    $[4] = t3;
+  } else {
+    t3 = $[4];
+  }
+  return t3;
 }
 
 ```

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-ternary.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp
 
 function Component({value}) {
   const [checked, setChecked] = useState('');

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-used-outside-effect-no-error.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function MockComponent({onSet}) {
@@ -28,20 +28,50 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState } from "react";
 
-function MockComponent({ onSet }) {
-  return <div onClick={() => onSet("clicked")}>Mock Component</div>;
+function MockComponent(t0) {
+  const $ = _c(2);
+  const { onSet } = t0;
+  let t1;
+  if ($[0] !== onSet) {
+    t1 = <div onClick={() => onSet("clicked")}>Mock Component</div>;
+    $[0] = onSet;
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  return t1;
 }
 
-function Component({ propValue }) {
-  const [value, setValue] = useState(null);
-  useEffect(() => {
-    setValue(propValue);
-  }, [propValue]);
-
-  return <MockComponent onSet={setValue} />;
+function Component(t0) {
+  const $ = _c(4);
+  const { propValue } = t0;
+  const [, setValue] = useState(null);
+  let t1;
+  let t2;
+  if ($[0] !== propValue) {
+    t1 = () => {
+      setValue(propValue);
+    };
+    t2 = [propValue];
+    $[0] = propValue;
+    $[1] = t1;
+    $[2] = t2;
+  } else {
+    t1 = $[1];
+    t2 = $[2];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[3] === Symbol.for("react.memo_cache_sentinel")) {
+    t3 = <MockComponent onSet={setValue} />;
+    $[3] = t3;
+  } else {
+    t3 = $[3];
+  }
+  return t3;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -54,8 +84,8 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":126},"end":{"line":6,"column":1,"index":230},"filename":"derived-state-from-prop-setter-used-outside-effect-no-error.ts"},"fnName":"MockComponent","memoSlots":2,"memoBlocks":1,"memoValues":1,"prunedMemoBlocks":0,"prunedMemoValues":0}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":8,"column":0,"index":232},"end":{"line":15,"column":1,"index":421},"filename":"derived-state-from-prop-setter-used-outside-effect-no-error.ts"},"fnName":"Component","memoSlots":4,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":6,"column":1,"index":211},"filename":"derived-state-from-prop-setter-used-outside-effect-no-error.ts"},"fnName":"MockComponent","memoSlots":2,"memoBlocks":1,"memoValues":1,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":8,"column":0,"index":213},"end":{"line":15,"column":1,"index":402},"filename":"derived-state-from-prop-setter-used-outside-effect-no-error.ts"},"fnName":"Component","memoSlots":4,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-used-outside-effect-no-error.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function MockComponent({onSet}) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-with-side-effect.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({value}) {
@@ -26,18 +26,38 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState } from "react";
 
-function Component({ value }) {
+function Component(t0) {
+  const $ = _c(5);
+  const { value } = t0;
   const [localValue, setLocalValue] = useState("");
-
-  useEffect(() => {
-    setLocalValue(value);
-    document.title = `Value: ${value}`;
-  }, [value]);
-
-  return <div>{localValue}</div>;
+  let t1;
+  let t2;
+  if ($[0] !== value) {
+    t1 = () => {
+      setLocalValue(value);
+      document.title = `Value: ${value}`;
+    };
+    t2 = [value];
+    $[0] = value;
+    $[1] = t1;
+    $[2] = t2;
+  } else {
+    t1 = $[1];
+    t2 = $[2];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[3] !== localValue) {
+    t3 = <div>{localValue}</div>;
+    $[3] = localValue;
+    $[4] = t3;
+  } else {
+    t3 = $[4];
+  }
+  return t3;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -50,8 +70,8 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [value]\n\nData Flow Tree:\n└── value (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":8,"column":4,"index":233},"end":{"line":8,"column":17,"index":246},"filename":"derived-state-from-prop-with-side-effect.ts","identifierName":"setLocalValue"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":126},"end":{"line":13,"column":1,"index":346},"filename":"derived-state-from-prop-with-side-effect.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [value]\n\nData Flow Tree:\n└── value (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":8,"column":4,"index":214},"end":{"line":8,"column":17,"index":227},"filename":"derived-state-from-prop-with-side-effect.ts","identifierName":"setLocalValue"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":13,"column":1,"index":327},"filename":"derived-state-from-prop-with-side-effect.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-with-side-effect.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({value}) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-ref-and-state-no-error.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState, useRef} from 'react';
 
 export default function Component({test}) {
@@ -27,19 +27,39 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState, useRef } from "react";
 
-export default function Component({ test }) {
+export default function Component(t0) {
+  const $ = _c(5);
+  const { test } = t0;
   const [local, setLocal] = useState("");
 
   const myRef = useRef(null);
-
-  useEffect(() => {
-    setLocal(myRef.current + test);
-  }, [test]);
-
-  return <>{local}</>;
+  let t1;
+  let t2;
+  if ($[0] !== test) {
+    t1 = () => {
+      setLocal(myRef.current + test);
+    };
+    t2 = [test];
+    $[0] = test;
+    $[1] = t1;
+    $[2] = t2;
+  } else {
+    t1 = $[1];
+    t2 = $[2];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[3] !== local) {
+    t3 = <>{local}</>;
+    $[3] = local;
+    $[4] = t3;
+  } else {
+    t3 = $[4];
+  }
+  return t3;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -52,7 +72,7 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":149},"end":{"line":14,"column":1,"index":347},"filename":"derived-state-from-ref-and-state-no-error.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":130},"end":{"line":14,"column":1,"index":328},"filename":"derived-state-from-ref-and-state-no-error.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-ref-and-state-no-error.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState, useRef} from 'react';
 
 export default function Component({test}) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-contains-local-function-call.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({propValue}) {
@@ -30,22 +30,48 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState } from "react";
 
-function Component({ propValue }) {
+function Component(t0) {
+  const $ = _c(6);
+  const { propValue } = t0;
   const [value, setValue] = useState(null);
-
-  function localFunction() {
-    console.log("local function");
+  let t1;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    t1 = function localFunction() {
+      console.log("local function");
+    };
+    $[0] = t1;
+  } else {
+    t1 = $[0];
   }
-
-  useEffect(() => {
-    setValue(propValue);
-    localFunction();
-  }, [propValue]);
-
-  return <div>{value}</div>;
+  const localFunction = t1;
+  let t2;
+  let t3;
+  if ($[1] !== propValue) {
+    t2 = () => {
+      setValue(propValue);
+      localFunction();
+    };
+    t3 = [propValue];
+    $[1] = propValue;
+    $[2] = t2;
+    $[3] = t3;
+  } else {
+    t2 = $[2];
+    t3 = $[3];
+  }
+  useEffect(t2, t3);
+  let t4;
+  if ($[4] !== value) {
+    t4 = <div>{value}</div>;
+    $[4] = value;
+    $[5] = t4;
+  } else {
+    t4 = $[5];
+  }
+  return t4;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -58,8 +84,8 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [propValue]\n\nData Flow Tree:\n└── propValue (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":12,"column":4,"index":298},"end":{"line":12,"column":12,"index":306},"filename":"effect-contains-local-function-call.ts","identifierName":"setValue"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":126},"end":{"line":17,"column":1,"index":390},"filename":"effect-contains-local-function-call.ts"},"fnName":"Component","memoSlots":6,"memoBlocks":3,"memoValues":4,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [propValue]\n\nData Flow Tree:\n└── propValue (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":12,"column":4,"index":279},"end":{"line":12,"column":12,"index":287},"filename":"effect-contains-local-function-call.ts","identifierName":"setValue"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":17,"column":1,"index":371},"filename":"effect-contains-local-function-call.ts"},"fnName":"Component","memoSlots":6,"memoBlocks":3,"memoValues":4,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-contains-local-function-call.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({propValue}) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-contains-prop-function-call-no-error.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({propValue, onChange}) {
@@ -25,17 +25,43 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState } from "react";
 
-function Component({ propValue, onChange }) {
+function Component(t0) {
+  const $ = _c(7);
+  const { propValue, onChange } = t0;
   const [value, setValue] = useState(null);
-  useEffect(() => {
-    setValue(propValue);
-    onChange();
-  }, [propValue]);
-
-  return <div>{value}</div>;
+  let t1;
+  if ($[0] !== onChange || $[1] !== propValue) {
+    t1 = () => {
+      setValue(propValue);
+      onChange();
+    };
+    $[0] = onChange;
+    $[1] = propValue;
+    $[2] = t1;
+  } else {
+    t1 = $[2];
+  }
+  let t2;
+  if ($[3] !== propValue) {
+    t2 = [propValue];
+    $[3] = propValue;
+    $[4] = t2;
+  } else {
+    t2 = $[4];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[5] !== value) {
+    t3 = <div>{value}</div>;
+    $[5] = value;
+    $[6] = t3;
+  } else {
+    t3 = $[6];
+  }
+  return t3;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -48,8 +74,8 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":126},"end":{"line":12,"column":1,"index":325},"filename":"effect-contains-prop-function-call-no-error.ts"},"fnName":"Component","memoSlots":7,"memoBlocks":3,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":16,"column":41,"index":421},"end":{"line":16,"column":49,"index":429},"filename":"effect-contains-prop-function-call-no-error.ts"},"fnName":null,"memoSlots":0,"memoBlocks":0,"memoValues":0,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":12,"column":1,"index":306},"filename":"effect-contains-prop-function-call-no-error.ts"},"fnName":"Component","memoSlots":7,"memoBlocks":3,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":16,"column":41,"index":402},"end":{"line":16,"column":49,"index":410},"filename":"effect-contains-prop-function-call-no-error.ts"},"fnName":null,"memoSlots":0,"memoBlocks":0,"memoValues":0,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-contains-prop-function-call-no-error.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({propValue, onChange}) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-used-in-dep-array-still-errors.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
 function Component({prop}) {
   const [s, setS] = useState(0);
@@ -18,15 +18,36 @@ function Component({prop}) {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
-function Component({ prop }) {
-  const [s, setS] = useState(0);
-  useEffect(() => {
-    setS(prop);
-  }, [prop, setS]);
-
-  return <div>{prop}</div>;
+function Component(t0) {
+  const $ = _c(5);
+  const { prop } = t0;
+  const [, setS] = useState(0);
+  let t1;
+  let t2;
+  if ($[0] !== prop) {
+    t1 = () => {
+      setS(prop);
+    };
+    t2 = [prop, setS];
+    $[0] = prop;
+    $[1] = t1;
+    $[2] = t2;
+  } else {
+    t1 = $[1];
+    t2 = $[2];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[3] !== prop) {
+    t3 = <div>{prop}</div>;
+    $[3] = prop;
+    $[4] = t3;
+  } else {
+    t3 = $[4];
+  }
+  return t3;
 }
 
 ```
@@ -34,8 +55,8 @@ function Component({ prop }) {
 ## Logs
 
 ```
-{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [prop]\n\nData Flow Tree:\n└── prop (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":6,"column":4,"index":169},"end":{"line":6,"column":8,"index":173},"filename":"effect-used-in-dep-array-still-errors.ts","identifierName":"setS"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":3,"column":0,"index":83},"end":{"line":10,"column":1,"index":231},"filename":"effect-used-in-dep-array-still-errors.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [prop]\n\nData Flow Tree:\n└── prop (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":6,"column":4,"index":150},"end":{"line":6,"column":8,"index":154},"filename":"effect-used-in-dep-array-still-errors.ts","identifierName":"setS"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":3,"column":0,"index":64},"end":{"line":10,"column":1,"index":212},"filename":"effect-used-in-dep-array-still-errors.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-used-in-dep-array-still-errors.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
 function Component({prop}) {
   const [s, setS] = useState(0);

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-with-cleanup-function-depending-on-derived-computation-value.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
 import {useEffect, useState} from 'react';
 
@@ -29,26 +29,39 @@ function Component(file: File) {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
 import { useEffect, useState } from "react";
 
-function Component(file: File) {
+function Component(file) {
+  const $ = _c(5);
   const [imageUrl, setImageUrl] = useState(null);
-
-  /*
-   * Cleaning up the variable or a source of the variable used to setState
-   * inside the effect communicates that we always need to clean up something
-   * which is a valid use case for useEffect. In which case we want to
-   * avoid an throwing
-   */
-  useEffect(() => {
-    const imageUrlPrepared = URL.createObjectURL(file);
-    setImageUrl(imageUrlPrepared);
-    return () => URL.revokeObjectURL(imageUrlPrepared);
-  }, [file]);
-
-  return <Image src={imageUrl} xstyle={styles.imageSizeLimits} />;
+  let t0;
+  let t1;
+  if ($[0] !== file) {
+    t0 = () => {
+      const imageUrlPrepared = URL.createObjectURL(file);
+      setImageUrl(imageUrlPrepared);
+      return () => URL.revokeObjectURL(imageUrlPrepared);
+    };
+    t1 = [file];
+    $[0] = file;
+    $[1] = t0;
+    $[2] = t1;
+  } else {
+    t0 = $[1];
+    t1 = $[2];
+  }
+  useEffect(t0, t1);
+  let t2;
+  if ($[3] !== imageUrl) {
+    t2 = <Image src={imageUrl} xstyle={styles.imageSizeLimits} />;
+    $[3] = imageUrl;
+    $[4] = t2;
+  } else {
+    t2 = $[4];
+  }
+  return t2;
 }
 
 ```
@@ -56,7 +69,7 @@ function Component(file: File) {
 ## Logs
 
 ```
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":5,"column":0,"index":127},"end":{"line":21,"column":1,"index":719},"filename":"effect-with-cleanup-function-depending-on-derived-computation-value.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":5,"column":0,"index":108},"end":{"line":21,"column":1,"index":700},"filename":"effect-with-cleanup-function-depending-on-derived-computation-value.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-with-cleanup-function-depending-on-derived-computation-value.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
 import {useEffect, useState} from 'react';
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-with-global-function-call-no-error.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({propValue}) {
@@ -25,17 +25,38 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState } from "react";
 
-function Component({ propValue }) {
+function Component(t0) {
+  const $ = _c(5);
+  const { propValue } = t0;
   const [value, setValue] = useState(null);
-  useEffect(() => {
-    setValue(propValue);
-    globalCall();
-  }, [propValue]);
-
-  return <div>{value}</div>;
+  let t1;
+  let t2;
+  if ($[0] !== propValue) {
+    t1 = () => {
+      setValue(propValue);
+      globalCall();
+    };
+    t2 = [propValue];
+    $[0] = propValue;
+    $[1] = t1;
+    $[2] = t2;
+  } else {
+    t1 = $[1];
+    t2 = $[2];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[3] !== value) {
+    t3 = <div>{value}</div>;
+    $[3] = value;
+    $[4] = t3;
+  } else {
+    t3 = $[4];
+  }
+  return t3;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -48,7 +69,7 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":126},"end":{"line":12,"column":1,"index":317},"filename":"effect-with-global-function-call-no-error.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":12,"column":1,"index":298},"filename":"effect-with-global-function-call-no-error.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-with-global-function-call-no-error.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component({propValue}) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/from-props-setstate-in-effect-no-error.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @enableTreatSetIdentifiersAsStateSetters @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @enableTreatSetIdentifiersAsStateSetters @loggerTestOnly
 
 function Component({setParentState, prop}) {
   useEffect(() => {
@@ -17,14 +17,40 @@ function Component({setParentState, prop}) {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @enableTreatSetIdentifiersAsStateSetters @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @enableTreatSetIdentifiersAsStateSetters @loggerTestOnly
 
-function Component({ setParentState, prop }) {
-  useEffect(() => {
-    setParentState(prop);
-  }, [prop]);
-
-  return <div>{prop}</div>;
+function Component(t0) {
+  const $ = _c(7);
+  const { setParentState, prop } = t0;
+  let t1;
+  if ($[0] !== prop || $[1] !== setParentState) {
+    t1 = () => {
+      setParentState(prop);
+    };
+    $[0] = prop;
+    $[1] = setParentState;
+    $[2] = t1;
+  } else {
+    t1 = $[2];
+  }
+  let t2;
+  if ($[3] !== prop) {
+    t2 = [prop];
+    $[3] = prop;
+    $[4] = t2;
+  } else {
+    t2 = $[4];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[5] !== prop) {
+    t3 = <div>{prop}</div>;
+    $[5] = prop;
+    $[6] = t3;
+  } else {
+    t3 = $[6];
+  }
+  return t3;
 }
 
 ```
@@ -32,7 +58,7 @@ function Component({ setParentState, prop }) {
 ## Logs
 
 ```
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":3,"column":0,"index":124},"end":{"line":9,"column":1,"index":259},"filename":"from-props-setstate-in-effect-no-error.ts"},"fnName":"Component","memoSlots":7,"memoBlocks":3,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":3,"column":0,"index":105},"end":{"line":9,"column":1,"index":240},"filename":"from-props-setstate-in-effect-no-error.ts"},"fnName":"Component","memoSlots":7,"memoBlocks":3,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/from-props-setstate-in-effect-no-error.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @enableTreatSetIdentifiersAsStateSetters @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @enableTreatSetIdentifiersAsStateSetters @loggerTestOnly
 
 function Component({setParentState, prop}) {
   useEffect(() => {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/function-expression-mutation-edge-case.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
 function Component() {
   const [foo, setFoo] = useState({});
@@ -40,37 +40,66 @@ function Component() {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
 function Component() {
-  const [foo, setFoo] = useState({});
-  const [bar, setBar] = useState(new Set());
+  const $ = _c(9);
+  let t0;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    t0 = {};
+    $[0] = t0;
+  } else {
+    t0 = $[0];
+  }
+  const [foo, setFoo] = useState(t0);
+  let t1;
+  if ($[1] === Symbol.for("react.memo_cache_sentinel")) {
+    t1 = new Set();
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  const [bar] = useState(t1);
+  let t2;
+  let t3;
+  if ($[2] !== bar || $[3] !== foo) {
+    t2 = () => {
+      let isChanged = false;
 
-  /*
-   * isChanged is considered context of the effect's function expression,
-   * if we don't bail out of effect mutation derivation tracking, isChanged
-   * will inherit the sources of the effect's function expression.
-   *
-   * This is innacurate and with the multiple passes ends up causing an infinite loop.
-   */
-  useEffect(() => {
-    let isChanged = false;
+      const newData = foo.map((val) => {
+        bar.someMethod(val);
+        isChanged = true;
+      });
 
-    const newData = foo.map((val) => {
-      bar.someMethod(val);
-      isChanged = true;
-    });
+      if (isChanged) {
+        setFoo(newData);
+      }
+    };
 
-    if (isChanged) {
-      setFoo(newData);
-    }
-  }, [foo, bar]);
-
-  return (
-    <div>
-      {foo}, {bar}
-    </div>
-  );
+    t3 = [foo, bar];
+    $[2] = bar;
+    $[3] = foo;
+    $[4] = t2;
+    $[5] = t3;
+  } else {
+    t2 = $[4];
+    t3 = $[5];
+  }
+  useEffect(t2, t3);
+  let t4;
+  if ($[6] !== bar || $[7] !== foo) {
+    t4 = (
+      <div>
+        {foo}, {bar}
+      </div>
+    );
+    $[6] = bar;
+    $[7] = foo;
+    $[8] = t4;
+  } else {
+    t4 = $[8];
+  }
+  return t4;
 }
 
 ```
@@ -78,8 +107,8 @@ function Component() {
 ## Logs
 
 ```
-{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nState: [foo, bar]\n\nData Flow Tree:\n└── newData\n    ├── foo (State)\n    └── bar (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":23,"column":6,"index":682},"end":{"line":23,"column":12,"index":688},"filename":"function-expression-mutation-edge-case.ts","identifierName":"setFoo"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":3,"column":0,"index":83},"end":{"line":32,"column":1,"index":781},"filename":"function-expression-mutation-edge-case.ts"},"fnName":"Component","memoSlots":9,"memoBlocks":4,"memoValues":5,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nState: [foo, bar]\n\nData Flow Tree:\n└── newData\n    ├── foo (State)\n    └── bar (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":23,"column":6,"index":663},"end":{"line":23,"column":12,"index":669},"filename":"function-expression-mutation-edge-case.ts","identifierName":"setFoo"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":3,"column":0,"index":64},"end":{"line":32,"column":1,"index":762},"filename":"function-expression-mutation-edge-case.ts"},"fnName":"Component","memoSlots":9,"memoBlocks":4,"memoValues":5,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/function-expression-mutation-edge-case.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
 function Component() {
   const [foo, setFoo] = useState({});

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/invalid-derived-computation-in-effect.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component() {
@@ -28,20 +28,38 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState } from "react";
 
 function Component() {
-  const [firstName, setFirstName] = useState("Taylor");
-  const lastName = "Swift";
+  const $ = _c(5);
+  const [firstName] = useState("Taylor");
 
-  // 🔴 Avoid: redundant state and unnecessary Effect
   const [fullName, setFullName] = useState("");
-  useEffect(() => {
-    setFullName(firstName + " " + lastName);
-  }, [firstName, lastName]);
-
-  return <div>{fullName}</div>;
+  let t0;
+  let t1;
+  if ($[0] !== firstName) {
+    t0 = () => {
+      setFullName(firstName + " " + "Swift");
+    };
+    t1 = [firstName, "Swift"];
+    $[0] = firstName;
+    $[1] = t0;
+    $[2] = t1;
+  } else {
+    t0 = $[1];
+    t1 = $[2];
+  }
+  useEffect(t0, t1);
+  let t2;
+  if ($[3] !== fullName) {
+    t2 = <div>{fullName}</div>;
+    $[3] = fullName;
+    $[4] = t2;
+  } else {
+    t2 = $[4];
+  }
+  return t2;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -54,8 +72,8 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nState: [firstName]\n\nData Flow Tree:\n└── firstName (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":11,"column":4,"index":360},"end":{"line":11,"column":15,"index":371},"filename":"invalid-derived-computation-in-effect.ts","identifierName":"setFullName"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":126},"end":{"line":15,"column":1,"index":464},"filename":"invalid-derived-computation-in-effect.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nState: [firstName]\n\nData Flow Tree:\n└── firstName (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":11,"column":4,"index":341},"end":{"line":11,"column":15,"index":352},"filename":"invalid-derived-computation-in-effect.ts","identifierName":"setFullName"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":15,"column":1,"index":445},"filename":"invalid-derived-computation-in-effect.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/invalid-derived-computation-in-effect.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 function Component() {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/invalid-derived-state-from-computed-props.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 export default function Component(props) {
@@ -26,18 +26,39 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState } from "react";
 
 export default function Component(props) {
+  const $ = _c(7);
   const [displayValue, setDisplayValue] = useState("");
-
-  useEffect(() => {
-    const computed = props.prefix + props.value + props.suffix;
-    setDisplayValue(computed);
-  }, [props.prefix, props.value, props.suffix]);
-
-  return <div>{displayValue}</div>;
+  let t0;
+  let t1;
+  if ($[0] !== props.prefix || $[1] !== props.suffix || $[2] !== props.value) {
+    t0 = () => {
+      const computed = props.prefix + props.value + props.suffix;
+      setDisplayValue(computed);
+    };
+    t1 = [props.prefix, props.value, props.suffix];
+    $[0] = props.prefix;
+    $[1] = props.suffix;
+    $[2] = props.value;
+    $[3] = t0;
+    $[4] = t1;
+  } else {
+    t0 = $[3];
+    t1 = $[4];
+  }
+  useEffect(t0, t1);
+  let t2;
+  if ($[5] !== displayValue) {
+    t2 = <div>{displayValue}</div>;
+    $[5] = displayValue;
+    $[6] = t2;
+  } else {
+    t2 = $[6];
+  }
+  return t2;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -50,8 +71,8 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [props]\n\nData Flow Tree:\n└── computed\n    └── props (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":9,"column":4,"index":314},"end":{"line":9,"column":19,"index":329},"filename":"invalid-derived-state-from-computed-props.ts","identifierName":"setDisplayValue"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":141},"end":{"line":13,"column":1,"index":428},"filename":"invalid-derived-state-from-computed-props.ts"},"fnName":"Component","memoSlots":7,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [props]\n\nData Flow Tree:\n└── computed\n    └── props (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":9,"column":4,"index":295},"end":{"line":9,"column":19,"index":310},"filename":"invalid-derived-state-from-computed-props.ts","identifierName":"setDisplayValue"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":122},"end":{"line":13,"column":1,"index":409},"filename":"invalid-derived-state-from-computed-props.ts"},"fnName":"Component","memoSlots":7,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/invalid-derived-state-from-computed-props.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 export default function Component(props) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/invalid-derived-state-from-destructured-props.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 export default function Component({props}) {
@@ -27,19 +27,40 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState } from "react";
 
-export default function Component({ props }) {
+export default function Component(t0) {
+  const $ = _c(6);
+  const { props } = t0;
   const [fullName, setFullName] = useState(
     props.firstName + " " + props.lastName,
   );
-
-  useEffect(() => {
-    setFullName(props.firstName + " " + props.lastName);
-  }, [props.firstName, props.lastName]);
-
-  return <div>{fullName}</div>;
+  let t1;
+  let t2;
+  if ($[0] !== props.firstName || $[1] !== props.lastName) {
+    t1 = () => {
+      setFullName(props.firstName + " " + props.lastName);
+    };
+    t2 = [props.firstName, props.lastName];
+    $[0] = props.firstName;
+    $[1] = props.lastName;
+    $[2] = t1;
+    $[3] = t2;
+  } else {
+    t1 = $[2];
+    t2 = $[3];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[4] !== fullName) {
+    t3 = <div>{fullName}</div>;
+    $[4] = fullName;
+    $[5] = t3;
+  } else {
+    t3 = $[5];
+  }
+  return t3;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -52,8 +73,8 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [props]\n\nData Flow Tree:\n└── props (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":10,"column":4,"index":288},"end":{"line":10,"column":15,"index":299},"filename":"invalid-derived-state-from-destructured-props.ts","identifierName":"setFullName"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":141},"end":{"line":14,"column":1,"index":416},"filename":"invalid-derived-state-from-destructured-props.ts"},"fnName":"Component","memoSlots":6,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [props]\n\nData Flow Tree:\n└── props (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":10,"column":4,"index":269},"end":{"line":10,"column":15,"index":280},"filename":"invalid-derived-state-from-destructured-props.ts","identifierName":"setFullName"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":122},"end":{"line":14,"column":1,"index":397},"filename":"invalid-derived-state-from-destructured-props.ts"},"fnName":"Component","memoSlots":6,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/invalid-derived-state-from-destructured-props.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState} from 'react';
 
 export default function Component({props}) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/ref-conditional-in-effect-no-error.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState, useRef} from 'react';
 
 export default function Component({test}) {
@@ -31,23 +31,44 @@ export const FIXTURE_ENTRYPOINT = {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import { useEffect, useState, useRef } from "react";
 
-export default function Component({ test }) {
+export default function Component(t0) {
+  const $ = _c(5);
+  const { test } = t0;
   const [local, setLocal] = useState(0);
 
   const myRef = useRef(null);
+  let t1;
+  let t2;
+  if ($[0] !== test) {
+    t1 = () => {
+      if (myRef.current) {
+        setLocal(test);
+      } else {
+        setLocal(test + test);
+      }
+    };
 
-  useEffect(() => {
-    if (myRef.current) {
-      setLocal(test);
-    } else {
-      setLocal(test + test);
-    }
-  }, [test]);
-
-  return <>{local}</>;
+    t2 = [test];
+    $[0] = test;
+    $[1] = t1;
+    $[2] = t2;
+  } else {
+    t1 = $[1];
+    t2 = $[2];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[3] !== local) {
+    t3 = <>{local}</>;
+    $[3] = local;
+    $[4] = t3;
+  } else {
+    t3 = $[4];
+  }
+  return t3;
 }
 
 export const FIXTURE_ENTRYPOINT = {
@@ -60,7 +81,7 @@ export const FIXTURE_ENTRYPOINT = {
 ## Logs
 
 ```
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":149},"end":{"line":18,"column":1,"index":405},"filename":"ref-conditional-in-effect-no-error.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":130},"end":{"line":18,"column":1,"index":386},"filename":"ref-conditional-in-effect-no-error.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/ref-conditional-in-effect-no-error.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 import {useEffect, useState, useRef} from 'react';
 
 export default function Component({test}) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/usestate-derived-from-prop-no-show-in-data-flow-tree.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
 function Component({prop}) {
   const [s, setS] = useState();
@@ -26,23 +26,37 @@ function Component({prop}) {
 ## Code
 
 ```javascript
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
-function Component({ prop }) {
+function Component(t0) {
+  const $ = _c(5);
+  const { prop } = t0;
   const [s, setS] = useState();
-  const [second, setSecond] = useState(prop);
-
-  /*
-   * `second` is a source of state. It will inherit the value of `prop` in
-   * the first render, but after that it will no longer be updated when
-   * `prop` changes. So we shouldn't consider `second` as being derived from
-   * `prop`
-   */
-  useEffect(() => {
-    setS(second);
-  }, [second]);
-
-  return <div>{s}</div>;
+  const [second] = useState(prop);
+  let t1;
+  let t2;
+  if ($[0] !== second) {
+    t1 = () => {
+      setS(second);
+    };
+    t2 = [second];
+    $[0] = second;
+    $[1] = t1;
+    $[2] = t2;
+  } else {
+    t1 = $[1];
+    t2 = $[2];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[3] !== s) {
+    t3 = <div>{s}</div>;
+    $[3] = s;
+    $[4] = t3;
+  } else {
+    t3 = $[4];
+  }
+  return t3;
 }
 
 ```
@@ -50,8 +64,8 @@ function Component({ prop }) {
 ## Logs
 
 ```
-{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nState: [second]\n\nData Flow Tree:\n└── second (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":14,"column":4,"index":462},"end":{"line":14,"column":8,"index":466},"filename":"usestate-derived-from-prop-no-show-in-data-flow-tree.ts","identifierName":"setS"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
-{"kind":"CompileSuccess","fnLoc":{"start":{"line":3,"column":0,"index":83},"end":{"line":18,"column":1,"index":519},"filename":"usestate-derived-from-prop-no-show-in-data-flow-tree.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
+{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nState: [second]\n\nData Flow Tree:\n└── second (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":14,"column":4,"index":443},"end":{"line":14,"column":8,"index":447},"filename":"usestate-derived-from-prop-no-show-in-data-flow-tree.ts","identifierName":"setS"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
+{"kind":"CompileSuccess","fnLoc":{"start":{"line":3,"column":0,"index":64},"end":{"line":18,"column":1,"index":500},"filename":"usestate-derived-from-prop-no-show-in-data-flow-tree.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
 ```
       
 ### Eval output

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/usestate-derived-from-prop-no-show-in-data-flow-tree.js

@@ -1,4 +1,4 @@
-// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly @outputMode:"lint"
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
 
 function Component({prop}) {
   const [s, setS] = useState();

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

@@ -5,7 +5,6 @@
 function Component() {
   const Foo = () => {
     someGlobal = true;
-    return <div />;
   };
   return <Foo />;
 }
@@ -27,9 +26,9 @@ error.assign-global-in-component-tag-function.ts:3:4
   2 |   const Foo = () => {
 > 3 |     someGlobal = true;
     |     ^^^^^^^^^^ `someGlobal` cannot be reassigned
-  4 |     return <div />;
-  5 |   };
-  6 |   return <Foo />;
+  4 |   };
+  5 |   return <Foo />;
+  6 | }
 ```
           
       

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

@@ -1,7 +1,6 @@
 function Component() {
   const Foo = () => {
     someGlobal = true;
-    return <div />;
   };
   return <Foo />;
 }

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

@@ -5,7 +5,6 @@
 function Component() {
   const foo = () => {
     someGlobal = true;
-    return <div />;
   };
   // Children are generally access/called during render, so
   // modifying a global in a children function is almost
@@ -30,9 +29,9 @@ error.assign-global-in-jsx-children.ts:3:4
   2 |   const foo = () => {
 > 3 |     someGlobal = true;
     |     ^^^^^^^^^^ `someGlobal` cannot be reassigned
-  4 |     return <div />;
-  5 |   };
-  6 |   // Children are generally access/called during render, so
+  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-children.js

@@ -1,7 +1,6 @@
 function Component() {
   const foo = () => {
     someGlobal = true;
-    return <div />;
   };
   // Children are generally access/called during render, so
   // modifying a global in a children function is almost

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-access-ref-in-reducer-init.expect.md

@@ -26,9 +26,9 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 2 errors:
+Found 1 error:
 
-Error: Cannot access ref value during render
+Error: Cannot access refs during render
 
 React refs are values that are not needed for rendering. Refs should only be accessed outside of render, such as in event handlers or effects. Accessing a ref value (the `current` property) during render can cause your component not to update as expected (https://react.dev/reference/react/useRef).
 
@@ -36,29 +36,7 @@ error.invalid-access-ref-in-reducer-init.ts:8:4
    6 |     (state, action) => state + action,
    7 |     0,
 >  8 |     init => ref.current
-     |     ^^^^^^^^^^^^^^^^^^^ Ref value is used during render
-   9 |   );
-  10 |
-  11 |   return <Stringify state={state} />;
-
-Error: Cannot access ref value during render
-
-React refs are values that are not needed for rendering. Refs should only be accessed outside of render, such as in event handlers or effects. Accessing a ref value (the `current` property) during render can cause your component not to update as expected (https://react.dev/reference/react/useRef).
-
-error.invalid-access-ref-in-reducer-init.ts:11:27
-   9 |   );
-  10 |
-> 11 |   return <Stringify state={state} />;
-     |                            ^^^^^ Ref value is used during render
-  12 | }
-  13 |
-  14 | export const FIXTURE_ENTRYPOINT = {
-
-error.invalid-access-ref-in-reducer-init.ts:8:4
-   6 |     (state, action) => state + action,
-   7 |     0,
->  8 |     init => ref.current
-     |     ^^^^^^^^^^^^^^^^^^^ Ref is initially accessed
+     |     ^^^^^^^^^^^^^^^^^^^ Passing a ref to a function may read its value during render
    9 |   );
   10 |
   11 |   return <Stringify state={state} />;

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

@@ -22,9 +22,9 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 2 errors:
+Found 1 error:
 
-Error: Cannot access ref value during render
+Error: Cannot access refs during render
 
 React refs are values that are not needed for rendering. Refs should only be accessed outside of render, such as in event handlers or effects. Accessing a ref value (the `current` property) during render can cause your component not to update as expected (https://react.dev/reference/react/useRef).
 
@@ -32,29 +32,7 @@ error.invalid-access-ref-in-reducer.ts:5:29
   3 | function Component(props) {
   4 |   const ref = useRef(props.value);
 > 5 |   const [state] = useReducer(() => ref.current, null);
-    |                              ^^^^^^^^^^^^^^^^^ Ref value is used during render
-  6 |
-  7 |   return <Stringify state={state} />;
-  8 | }
-
-Error: Cannot access ref value during render
-
-React refs are values that are not needed for rendering. Refs should only be accessed outside of render, such as in event handlers or effects. Accessing a ref value (the `current` property) during render can cause your component not to update as expected (https://react.dev/reference/react/useRef).
-
-error.invalid-access-ref-in-reducer.ts:7:27
-   5 |   const [state] = useReducer(() => ref.current, null);
-   6 |
->  7 |   return <Stringify state={state} />;
-     |                            ^^^^^ Ref value is used during render
-   8 | }
-   9 |
-  10 | export const FIXTURE_ENTRYPOINT = {
-
-error.invalid-access-ref-in-reducer.ts:5:29
-  3 | function Component(props) {
-  4 |   const ref = useRef(props.value);
-> 5 |   const [state] = useReducer(() => ref.current, null);
-    |                              ^^^^^^^^^^^^^^^^^ Ref is initially accessed
+    |                              ^^^^^^^^^^^^^^^^^ Passing a ref to a function may read its value during render
   6 |
   7 |   return <Stringify state={state} />;
   8 | }

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-access-ref-in-render-mutate-object-with-ref-function.expect.md

@@ -20,26 +20,18 @@ function Component() {
 ```
 Found 1 error:
 
-Error: Cannot access ref value during render
+Error: Cannot access refs during render
 
 React refs are values that are not needed for rendering. Refs should only be accessed outside of render, such as in event handlers or effects. Accessing a ref value (the `current` property) during render can cause your component not to update as expected (https://react.dev/reference/react/useRef).
 
-error.invalid-access-ref-in-render-mutate-object-with-ref-function.ts:8:15
+error.invalid-access-ref-in-render-mutate-object-with-ref-function.ts:7:19
+   5 |   const object = {};
    6 |   object.foo = () => ref.current;
-   7 |   const refValue = object.foo();
->  8 |   return <div>{refValue}</div>;
-     |                ^^^^^^^^ Ref value is used during render
+>  7 |   const refValue = object.foo();
+     |                    ^^^^^^^^^^ This function accesses a ref value
+   8 |   return <div>{refValue}</div>;
    9 | }
   10 |
-
-error.invalid-access-ref-in-render-mutate-object-with-ref-function.ts:6:15
-  4 |   const ref = useRef(null);
-  5 |   const object = {};
-> 6 |   object.foo = () => ref.current;
-    |                ^^^^^^^^^^^^^^^^^ Ref is initially accessed
-  7 |   const refValue = object.foo();
-  8 |   return <div>{refValue}</div>;
-  9 | }
 ```