[compiler] Adjustments to exhaustive deps messages, disable the lint rule

Similar to ValidateHookUsage, we implement this check in the compiler for safety but (for now) continue to rely on the existing rule for actually reporting errors to users.

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

@@ -304,6 +304,30 @@ export class CompilerError extends Error {
   disabledDetails: Array<CompilerErrorDetail | CompilerDiagnostic> = [];
   printedMessage: string | null = null;
 
+  static simpleInvariant(
+    condition: unknown,
+    options: {
+      reason: CompilerDiagnosticOptions['reason'];
+      description?: CompilerDiagnosticOptions['description'];
+      loc: SourceLocation;
+    },
+  ): asserts condition {
+    if (!condition) {
+      const errors = new CompilerError();
+      errors.pushDiagnostic(
+        CompilerDiagnostic.create({
+          reason: options.reason,
+          description: options.description ?? null,
+          category: ErrorCategory.Invariant,
+        }).withDetails({
+          kind: 'error',
+          loc: options.loc,
+          message: options.reason,
+        }),
+      );
+      throw errors;
+    }
+  }
   static invariant(
     condition: unknown,
     options: Omit<CompilerDiagnosticOptions, 'category'>,
@@ -576,7 +600,8 @@ function printErrorSummary(category: ErrorCategory, message: string): string {
     case ErrorCategory.Suppression:
     case ErrorCategory.Syntax:
     case ErrorCategory.UseMemo:
-    case ErrorCategory.VoidUseMemo: {
+    case ErrorCategory.VoidUseMemo:
+    case ErrorCategory.MemoDependencies: {
       heading = 'Error';
       break;
     }
@@ -634,6 +659,10 @@ export enum ErrorCategory {
    * Checks that manual memoization is preserved
    */
   PreserveManualMemo = 'PreserveManualMemo',
+  /**
+   * Checks for exhaustive useMemo/useCallback dependencies without extraneous values
+   */
+  MemoDependencies = 'MemoDependencies',
   /**
    * Checks for known incompatible libraries
    */
@@ -1031,6 +1060,24 @@ function getRuleForCategoryImpl(category: ErrorCategory): LintRule {
         preset: LintRulePreset.RecommendedLatest,
       };
     }
+    case ErrorCategory.MemoDependencies: {
+      return {
+        category,
+        severity: ErrorSeverity.Error,
+        name: 'memo-dependencies',
+        description:
+          'Validates that useMemo() and useCallback() specify comprehensive dependencies without extraneous values. See [`useMemo()` docs](https://react.dev/reference/react/useMemo) for more information.',
+        /**
+         * TODO: the "MemoDependencies" rule largely reimplements the "exhaustive-deps" non-compiler rule,
+         * allowing the compiler to ensure it does not regress change behavior due to different dependencies.
+         * We previously relied on the source having ESLint suppressions for any exhaustive-deps violations,
+         * but it's more reliable to verify it within the compiler.
+         *
+         * Long-term we should de-duplicate these implementations.
+         */
+        preset: LintRulePreset.Off,
+      };
+    }
     case ErrorCategory.IncompatibleLibrary: {
       return {
         category,

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

@@ -105,6 +105,7 @@ import {validateNoDerivedComputationsInEffects} from '../Validation/ValidateNoDe
 import {validateNoDerivedComputationsInEffects_exp} from '../Validation/ValidateNoDerivedComputationsInEffects_exp';
 import {nameAnonymousFunctions} from '../Transform/NameAnonymousFunctions';
 import {optimizeForSSR} from '../Optimization/OptimizeForSSR';
+import {validateExhaustiveDependencies} from '../Validation/ValidateExhaustiveDependencies';
 import {validateSourceLocations} from '../Validation/ValidateSourceLocations';
 
 export type CompilerPipelineValue =
@@ -302,6 +303,13 @@ function runWithEnvironment(
   inferReactivePlaces(hir);
   log({kind: 'hir', name: 'InferReactivePlaces', value: hir});
 
+  if (env.enableValidations) {
+    if (env.config.validateExhaustiveMemoizationDependencies) {
+      // NOTE: this relies on reactivity inference running first
+      validateExhaustiveDependencies(hir).unwrap();
+    }
+  }
+
   rewriteInstructionKindsBasedOnReassignment(hir);
   log({
     kind: 'hir',

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

@@ -400,7 +400,15 @@ export function compileProgram(
    */
   const suppressions = findProgramSuppressions(
     pass.comments,
-    pass.opts.eslintSuppressionRules ?? DEFAULT_ESLINT_SUPPRESSIONS,
+    /*
+     * If the compiler is validating hooks rules and exhaustive memo dependencies, we don't need to check
+     * for React ESLint suppressions
+     */
+    pass.opts.environment.validateExhaustiveMemoizationDependencies &&
+      pass.opts.environment.validateHooksUsage
+      ? null
+      : (pass.opts.eslintSuppressionRules ?? DEFAULT_ESLINT_SUPPRESSIONS),
+    // Always bail on Flow suppressions
     pass.opts.flowSuppressions,
   );
 

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

@@ -78,7 +78,7 @@ export function filterSuppressionsThatAffectFunction(
 
 export function findProgramSuppressions(
   programComments: Array<t.Comment>,
-  ruleNames: Array<string>,
+  ruleNames: Array<string> | null,
   flowSuppressions: boolean,
 ): Array<SuppressionRange> {
   const suppressionRanges: Array<SuppressionRange> = [];
@@ -89,7 +89,7 @@ export function findProgramSuppressions(
   let disableNextLinePattern: RegExp | null = null;
   let disablePattern: RegExp | null = null;
   let enablePattern: RegExp | null = null;
-  if (ruleNames.length !== 0) {
+  if (ruleNames != null && ruleNames.length !== 0) {
     const rulePattern = `(${ruleNames.join('|')})`;
     disableNextLinePattern = new RegExp(
       `eslint-disable-next-line ${rulePattern}`,

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

@@ -218,6 +218,11 @@ export const EnvironmentConfigSchema = z.object({
    */
   validatePreserveExistingMemoizationGuarantees: z.boolean().default(true),
 
+  /**
+   * Validate that dependencies supplied to manual memoization calls are exhaustive.
+   */
+  validateExhaustiveMemoizationDependencies: z.boolean().default(false),
+
   /**
    * When this is true, rather than pruning existing manual memoization but ensuring or validating
    * that the memoized values remain memoized, the compiler will simply not prune existing calls to

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

@@ -817,6 +817,11 @@ export type StartMemoize = {
    * (e.g. useMemo without a second arg)
    */
   deps: Array<ManualMemoDependency> | null;
+  /**
+   * The source location of the dependencies argument. Used for
+   * emitting diagnostics with a suggested replacement
+   */
+  depsLoc: SourceLocation | null;
   loc: SourceLocation;
 };
 export type FinishMemoize = {
@@ -1680,6 +1685,28 @@ export function areEqualPaths(a: DependencyPath, b: DependencyPath): boolean {
     )
   );
 }
+export function isSubPath(
+  subpath: DependencyPath,
+  path: DependencyPath,
+): boolean {
+  return (
+    subpath.length <= path.length &&
+    subpath.every(
+      (item, ix) =>
+        item.property === path[ix].property &&
+        item.optional === path[ix].optional,
+    )
+  );
+}
+export function isSubPathIgnoringOptionals(
+  subpath: DependencyPath,
+  path: DependencyPath,
+): boolean {
+  return (
+    subpath.length <= path.length &&
+    subpath.every((item, ix) => item.property === path[ix].property)
+  );
+}
 
 export function getPlaceScope(
   id: InstructionId,

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

@@ -42,7 +42,7 @@ type IdentifierSidemap = {
   functions: Map<IdentifierId, TInstruction<FunctionExpression>>;
   manualMemos: Map<IdentifierId, ManualMemoCallee>;
   react: Set<IdentifierId>;
-  maybeDepsLists: Map<IdentifierId, Array<Place>>;
+  maybeDepsLists: Map<IdentifierId, {loc: SourceLocation; deps: Array<Place>}>;
   maybeDeps: Map<IdentifierId, ManualMemoDependency>;
   optionals: Set<IdentifierId>;
 };
@@ -159,10 +159,10 @@ function collectTemporaries(
     }
     case 'ArrayExpression': {
       if (value.elements.every(e => e.kind === 'Identifier')) {
-        sidemap.maybeDepsLists.set(
-          instr.lvalue.identifier.id,
-          value.elements as Array<Place>,
-        );
+        sidemap.maybeDepsLists.set(instr.lvalue.identifier.id, {
+          loc: value.loc,
+          deps: value.elements as Array<Place>,
+        });
       }
       break;
     }
@@ -182,6 +182,7 @@ function makeManualMemoizationMarkers(
   fnExpr: Place,
   env: Environment,
   depsList: Array<ManualMemoDependency> | null,
+  depsLoc: SourceLocation | null,
   memoDecl: Place,
   manualMemoId: number,
 ): [TInstruction<StartMemoize>, TInstruction<FinishMemoize>] {
@@ -197,6 +198,7 @@ function makeManualMemoizationMarkers(
          * as dependencies
          */
         deps: depsList,
+        depsLoc,
         loc: fnExpr.loc,
       },
       effects: null,
@@ -287,86 +289,85 @@ function extractManualMemoizationArgs(
   sidemap: IdentifierSidemap,
   errors: CompilerError,
 ): {
-  fnPlace: Place | null;
+  fnPlace: Place;
   depsList: Array<ManualMemoDependency> | null;
-} {
+  depsLoc: SourceLocation | null;
+} | null {
   const [fnPlace, depsListPlace] = instr.value.args as Array<
     Place | SpreadPattern | undefined
   >;
-  if (fnPlace == null) {
+  if (fnPlace == null || fnPlace.kind !== 'Identifier') {
     errors.pushDiagnostic(
       CompilerDiagnostic.create({
         category: ErrorCategory.UseMemo,
         reason: `Expected a callback function to be passed to ${kind}`,
-        description: `Expected a callback function to be passed to ${kind}`,
+        description:
+          kind === 'useCallback'
+            ? 'The first argument to useCallback() must be a function to cache'
+            : 'The first argument to useMemo() must be a function that calculates a result to cache',
         suggestions: null,
       }).withDetails({
         kind: 'error',
         loc: instr.value.loc,
-        message: `Expected a callback function to be passed to ${kind}`,
+        message:
+          kind === 'useCallback'
+            ? `Expected a callback function`
+            : `Expected a memoization function`,
       }),
     );
-    return {fnPlace: null, depsList: null};
+    return null;
   }
-  if (fnPlace.kind === 'Spread' || depsListPlace?.kind === 'Spread') {
+  if (depsListPlace == null) {
+    return {
+      fnPlace,
+      depsList: null,
+      depsLoc: null,
+    };
+  }
+  const maybeDepsList =
+    depsListPlace.kind === 'Identifier'
+      ? sidemap.maybeDepsLists.get(depsListPlace.identifier.id)
+      : null;
+  if (maybeDepsList == null) {
     errors.pushDiagnostic(
       CompilerDiagnostic.create({
         category: ErrorCategory.UseMemo,
-        reason: `Unexpected spread argument to ${kind}`,
-        description: `Unexpected spread argument to ${kind}`,
+        reason: `Expected the dependency list for ${kind} to be an array literal`,
+        description: `Expected the dependency list for ${kind} to be an array literal`,
         suggestions: null,
       }).withDetails({
         kind: 'error',
-        loc: instr.value.loc,
-        message: `Unexpected spread argument to ${kind}`,
+        loc:
+          depsListPlace?.kind === 'Identifier' ? depsListPlace.loc : instr.loc,
+        message: `Expected the dependency list for ${kind} to be an array literal`,
       }),
     );
-    return {fnPlace: null, depsList: null};
+    return null;
   }
-  let depsList: Array<ManualMemoDependency> | null = null;
-  if (depsListPlace != null) {
-    const maybeDepsList = sidemap.maybeDepsLists.get(
-      depsListPlace.identifier.id,
-    );
-    if (maybeDepsList == null) {
+  const depsList: Array<ManualMemoDependency> = [];
+  for (const dep of maybeDepsList.deps) {
+    const maybeDep = sidemap.maybeDeps.get(dep.identifier.id);
+    if (maybeDep == null) {
       errors.pushDiagnostic(
         CompilerDiagnostic.create({
           category: ErrorCategory.UseMemo,
-          reason: `Expected the dependency list for ${kind} to be an array literal`,
-          description: `Expected the dependency list for ${kind} to be an array literal`,
+          reason: `Expected the dependency list to be an array of simple expressions (e.g. \`x\`, \`x.y.z\`, \`x?.y?.z\`)`,
+          description: `Expected the dependency list to be an array of simple expressions (e.g. \`x\`, \`x.y.z\`, \`x?.y?.z\`)`,
           suggestions: null,
         }).withDetails({
           kind: 'error',
-          loc: depsListPlace.loc,
-          message: `Expected the dependency list for ${kind} to be an array literal`,
+          loc: dep.loc,
+          message: `Expected the dependency list to be an array of simple expressions (e.g. \`x\`, \`x.y.z\`, \`x?.y?.z\`)`,
         }),
       );
-      return {fnPlace, depsList: null};
-    }
-    depsList = [];
-    for (const dep of maybeDepsList) {
-      const maybeDep = sidemap.maybeDeps.get(dep.identifier.id);
-      if (maybeDep == null) {
-        errors.pushDiagnostic(
-          CompilerDiagnostic.create({
-            category: ErrorCategory.UseMemo,
-            reason: `Expected the dependency list to be an array of simple expressions (e.g. \`x\`, \`x.y.z\`, \`x?.y?.z\`)`,
-            description: `Expected the dependency list to be an array of simple expressions (e.g. \`x\`, \`x.y.z\`, \`x?.y?.z\`)`,
-            suggestions: null,
-          }).withDetails({
-            kind: 'error',
-            loc: dep.loc,
-            message: `Expected the dependency list to be an array of simple expressions (e.g. \`x\`, \`x.y.z\`, \`x?.y?.z\`)`,
-          }),
-        );
-      } else {
-        depsList.push(maybeDep);
-      }
+    } else {
+      depsList.push(maybeDep);
     }
   }
   return {
     fnPlace,
     depsList,
+    depsLoc: maybeDepsList.loc,
   };
 }
 
@@ -427,16 +428,17 @@ export function dropManualMemoization(
 
         const manualMemo = sidemap.manualMemos.get(id);
         if (manualMemo != null) {
-          const {fnPlace, depsList} = extractManualMemoizationArgs(
+          const memoDetails = extractManualMemoizationArgs(
             instr as TInstruction<CallExpression> | TInstruction<MethodCall>,
             manualMemo.kind,
             sidemap,
             errors,
           );
 
-          if (fnPlace == null) {
+          if (memoDetails == null) {
             continue;
           }
+          const {fnPlace, depsList, depsLoc} = memoDetails;
 
           instr.value = getManualMemoizationReplacement(
             fnPlace,
@@ -487,6 +489,7 @@ export function dropManualMemoization(
               fnPlace,
               func.env,
               depsList,
+              depsLoc,
               memoDecl,
               nextManualMemoId++,
             );

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

@@ -0,0 +1,824 @@
+/**
+ * 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 prettyFormat from 'pretty-format';
+import {
+  CompilerDiagnostic,
+  CompilerError,
+  CompilerSuggestionOperation,
+  SourceLocation,
+} from '..';
+import {CompilerSuggestion, ErrorCategory} from '../CompilerError';
+import {
+  areEqualPaths,
+  BlockId,
+  DependencyPath,
+  FinishMemoize,
+  HIRFunction,
+  Identifier,
+  IdentifierId,
+  InstructionKind,
+  isStableType,
+  isSubPath,
+  isSubPathIgnoringOptionals,
+  isUseRefType,
+  LoadGlobal,
+  ManualMemoDependency,
+  Place,
+  StartMemoize,
+} from '../HIR';
+import {
+  eachInstructionLValue,
+  eachInstructionValueLValue,
+  eachInstructionValueOperand,
+  eachTerminalOperand,
+} from '../HIR/visitors';
+import {Result} from '../Utils/Result';
+import {retainWhere} from '../Utils/utils';
+
+const DEBUG = false;
+
+/**
+ * Validates that existing manual memoization is exhaustive and does not
+ * have extraneous dependencies. The goal of the validation is to ensure
+ * that auto-memoization will not substantially change the behavior of
+ * the program:
+ * - If the manual dependencies were non-exhaustive (missing important deps)
+ *   then auto-memoization will include those dependencies, and cause the
+ *   value to update *more* frequently.
+ * - If the manual dependencies had extraneous deps, then auto memoization
+ *   will remove them and cause the value to update *less* frequently.
+ *
+ * We consider a value V as missing if ALL of the following conditions are met:
+ * - V is reactive
+ * - There is no manual dependency path P such that whenever V would change,
+ *   P would also change. If V is `x.y.z`, this means there must be some
+ *   path P that is either `x.y.z`, `x.y`, or `x`. Note that we assume no
+ *   interior mutability, such that a shorter path "covers" changes to longer
+ *   more precise paths.
+ *
+ * We consider a value V extraneous if either of the folowing are true:
+ * - V is a reactive local that is unreferenced
+ * - V is a global that is unreferenced
+ *
+ * In other words, we allow extraneous non-reactive values since we know they cannot
+ * impact how often the memoization would run.
+ *
+ * ## TODO: Invalid, Complex Deps
+ *
+ * Handle cases where the user deps were not simple identifiers + property chains.
+ * We try to detect this in ValidateUseMemo but we miss some cases. The problem
+ * is that invalid forms can be value blocks or function calls that don't get
+ * removed by DCE, leaving a structure like:
+ *
+ * StartMemoize
+ * t0 = <value to memoize>
+ * ...non-DCE'd code for manual deps...
+ * FinishMemoize decl=t0
+ *
+ * When we go to compute the dependencies, we then think that the user's manual dep
+ * logic is part of what the memo computation logic.
+ */
+export function validateExhaustiveDependencies(
+  fn: HIRFunction,
+): Result<void, CompilerError> {
+  const reactive = collectReactiveIdentifiersHIR(fn);
+
+  const temporaries: Map<IdentifierId, Temporary> = new Map();
+  for (const param of fn.params) {
+    const place = param.kind === 'Identifier' ? param : param.place;
+    temporaries.set(place.identifier.id, {
+      kind: 'Local',
+      identifier: place.identifier,
+      path: [],
+      context: false,
+      loc: place.loc,
+    });
+  }
+  const error = new CompilerError();
+  let startMemo: StartMemoize | null = null;
+
+  function onStartMemoize(
+    value: StartMemoize,
+    dependencies: Set<InferredDependency>,
+    locals: Set<IdentifierId>,
+  ): void {
+    CompilerError.simpleInvariant(startMemo == null, {
+      reason: 'Unexpected nested memo calls',
+      loc: value.loc,
+    });
+    startMemo = value;
+    dependencies.clear();
+    locals.clear();
+  }
+  function onFinishMemoize(
+    value: FinishMemoize,
+    dependencies: Set<InferredDependency>,
+    locals: Set<IdentifierId>,
+  ): void {
+    CompilerError.simpleInvariant(
+      startMemo != null && startMemo.manualMemoId === value.manualMemoId,
+      {
+        reason: 'Found FinishMemoize without corresponding StartMemoize',
+        loc: value.loc,
+      },
+    );
+    visitCandidateDependency(value.decl, temporaries, dependencies, locals);
+    const inferred: Array<InferredDependency> = Array.from(dependencies);
+    // Sort dependencies by name and path, with shorter/non-optional paths first
+    inferred.sort((a, b) => {
+      if (a.kind === 'Global' && b.kind == 'Global') {
+        return a.binding.name.localeCompare(b.binding.name);
+      } else if (a.kind == 'Local' && b.kind == 'Local') {
+        CompilerError.simpleInvariant(
+          a.identifier.name != null &&
+            a.identifier.name.kind === 'named' &&
+            b.identifier.name != null &&
+            b.identifier.name.kind === 'named',
+          {
+            reason: 'Expected dependencies to be named variables',
+            loc: a.loc,
+          },
+        );
+        if (a.identifier.id !== b.identifier.id) {
+          return a.identifier.name.value.localeCompare(b.identifier.name.value);
+        }
+        if (a.path.length !== b.path.length) {
+          // if a's path is shorter this returns a negative, sorting a first
+          return a.path.length - b.path.length;
+        }
+        for (let i = 0; i < a.path.length; i++) {
+          const aProperty = a.path[i];
+          const bProperty = b.path[i];
+          const aOptional = aProperty.optional ? 0 : 1;
+          const bOptional = bProperty.optional ? 0 : 1;
+          if (aOptional !== bOptional) {
+            // sort non-optionals first
+            return aOptional - bOptional;
+          } else if (aProperty.property !== bProperty.property) {
+            return String(aProperty.property).localeCompare(
+              String(bProperty.property),
+            );
+          }
+        }
+        return 0;
+      } else {
+        const aName =
+          a.kind === 'Global' ? a.binding.name : a.identifier.name?.value;
+        const bName =
+          b.kind === 'Global' ? b.binding.name : b.identifier.name?.value;
+        if (aName != null && bName != null) {
+          return aName.localeCompare(bName);
+        }
+        return 0;
+      }
+    });
+    // remove redundant inferred dependencies
+    retainWhere(inferred, (dep, ix) => {
+      const match = inferred.findIndex(prevDep => {
+        return (
+          isEqualTemporary(prevDep, dep) ||
+          (prevDep.kind === 'Local' &&
+            dep.kind === 'Local' &&
+            prevDep.identifier.id === dep.identifier.id &&
+            isSubPath(prevDep.path, dep.path))
+        );
+      });
+      // only retain entries that don't have a prior match
+      return match === -1 || match >= ix;
+    });
+    // Validate that all manual dependencies belong there
+    if (DEBUG) {
+      console.log('manual');
+      console.log(
+        (startMemo.deps ?? [])
+          .map(x => '  ' + printManualMemoDependency(x))
+          .join('\n'),
+      );
+      console.log('inferred');
+      console.log(
+        inferred.map(x => '  ' + printInferredDependency(x)).join('\n'),
+      );
+    }
+    const manualDependencies = startMemo.deps ?? [];
+    const matched: Set<ManualMemoDependency> = new Set();
+    const missing: Array<Extract<InferredDependency, {kind: 'Local'}>> = [];
+    const extra: Array<ManualMemoDependency> = [];
+    for (const inferredDependency of inferred) {
+      if (inferredDependency.kind === 'Global') {
+        for (const manualDependency of manualDependencies) {
+          if (
+            manualDependency.root.kind === 'Global' &&
+            manualDependency.root.identifierName ===
+              inferredDependency.binding.name
+          ) {
+            matched.add(manualDependency);
+            extra.push(manualDependency);
+          }
+        }
+        continue;
+      }
+      CompilerError.simpleInvariant(inferredDependency.kind === 'Local', {
+        reason: 'Unexpected function dependency',
+        loc: value.loc,
+      });
+      const isRequiredDependency = reactive.has(
+        inferredDependency.identifier.id,
+      );
+      let hasMatchingManualDependency = false;
+      for (const manualDependency of manualDependencies) {
+        if (
+          manualDependency.root.kind === 'NamedLocal' &&
+          manualDependency.root.value.identifier.id ===
+            inferredDependency.identifier.id &&
+          (areEqualPaths(manualDependency.path, inferredDependency.path) ||
+            isSubPathIgnoringOptionals(
+              manualDependency.path,
+              inferredDependency.path,
+            ))
+        ) {
+          hasMatchingManualDependency = true;
+          matched.add(manualDependency);
+          if (!isRequiredDependency) {
+            extra.push(manualDependency);
+          }
+        }
+      }
+      if (isRequiredDependency && !hasMatchingManualDependency) {
+        missing.push(inferredDependency);
+      }
+    }
+
+    for (const dep of startMemo.deps ?? []) {
+      if (matched.has(dep)) {
+        continue;
+      }
+      extra.push(dep);
+    }
+
+    /**
+     * Per docblock, we only consider dependencies as extraneous if
+     * they are unused globals or reactive locals. Notably, this allows
+     * non-reactive locals.
+     */
+    retainWhere(extra, dep => {
+      return dep.root.kind === 'Global' || dep.root.value.reactive;
+    });
+
+    if (missing.length !== 0 || extra.length !== 0) {
+      let suggestions: Array<CompilerSuggestion> | null = null;
+      if (startMemo.depsLoc != null && typeof startMemo.depsLoc !== 'symbol') {
+        suggestions = [
+          {
+            description: 'Update dependencies',
+            range: [startMemo.depsLoc.start.index, startMemo.depsLoc.end.index],
+            op: CompilerSuggestionOperation.Replace,
+            text: `[${inferred.map(printInferredDependency).join(', ')}]`,
+          },
+        ];
+      }
+      if (missing.length !== 0) {
+        const diagnostic = CompilerDiagnostic.create({
+          category: ErrorCategory.MemoDependencies,
+          reason: 'Found missing memoization dependencies',
+          description:
+            'Missing dependencies can cause a value not to update when those inputs change, ' +
+            'resulting in stale UI',
+          suggestions,
+        });
+        for (const dep of missing) {
+          let reactiveStableValueHint = '';
+          if (isStableType(dep.identifier)) {
+            reactiveStableValueHint =
+              '. Refs, setState functions, and other "stable" values generally do not need to be added as dependencies, but this variable may change over time to point to different values';
+          }
+          diagnostic.withDetails({
+            kind: 'error',
+            message: `Missing dependency \`${printInferredDependency(dep)}\`${reactiveStableValueHint}`,
+            loc: dep.loc,
+          });
+        }
+        error.pushDiagnostic(diagnostic);
+      } else if (extra.length !== 0) {
+        const diagnostic = CompilerDiagnostic.create({
+          category: ErrorCategory.MemoDependencies,
+          reason: 'Found unnecessary memoization dependencies',
+          description:
+            'Unnecessary dependencies can cause a value to update more often than necessary, ' +
+            'causing performance regressions and effects to fire more often than expected',
+        });
+        diagnostic.withDetails({
+          kind: 'error',
+          message: `Unnecessary dependencies ${extra.map(dep => `\`${printManualMemoDependency(dep)}\``).join(', ')}`,
+          loc: startMemo.depsLoc ?? value.loc,
+        });
+        error.pushDiagnostic(diagnostic);
+      }
+    }
+
+    dependencies.clear();
+    locals.clear();
+    startMemo = null;
+  }
+
+  collectDependencies(
+    fn,
+    temporaries,
+    {
+      onStartMemoize,
+      onFinishMemoize,
+    },
+    false, // isFunctionExpression
+  );
+  return error.asResult();
+}
+
+function addDependency(
+  dep: Temporary,
+  dependencies: Set<InferredDependency>,
+  locals: Set<IdentifierId>,
+): void {
+  if (dep.kind === 'Function') {
+    for (const x of dep.dependencies) {
+      addDependency(x, dependencies, locals);
+    }
+  } else if (dep.kind === 'Global') {
+    dependencies.add(dep);
+  } else if (!locals.has(dep.identifier.id)) {
+    dependencies.add(dep);
+  }
+}
+
+function visitCandidateDependency(
+  place: Place,
+  temporaries: Map<IdentifierId, Temporary>,
+  dependencies: Set<InferredDependency>,
+  locals: Set<IdentifierId>,
+): void {
+  const dep = temporaries.get(place.identifier.id);
+  if (dep != null) {
+    addDependency(dep, dependencies, locals);
+  }
+}
+
+/**
+ * This function determines the dependencies of the given function relative to
+ * its external context. Dependencies are collected eagerly, the first time an
+ * external variable is referenced, as opposed to trying to delay or aggregate
+ * calculation of dependencies until they are later "used".
+ *
+ * For example, in
+ *
+ * ```
+ * function f() {
+ *   let x = y; // we record a dependency on `y` here
+ *   ...
+ *   use(x); // as opposed to trying to delay that dependency until here
+ * }
+ * ```
+ *
+ * That said, LoadLocal/LoadContext does not immediately take a dependency,
+ * we store the dependency in a temporary and set it as used when that temporary
+ * is referenced as an operand.
+ *
+ * As we proceed through the function we track local variables that it creates
+ * and don't consider later references to these variables as dependencies.
+ *
+ * For function expressions we first collect the function's dependencies by
+ * calling this function recursively, _without_ taking into account whether
+ * the "external" variables it accesses are actually external or just locals
+ * in the parent. We then prune any locals and immediately consider any
+ * remaining externals that it accesses as a dependency:
+ *
+ * ```
+ * function Component() {
+ *   const local = ...;
+ *   const f = () => { return [external, local] };
+ * }
+ * ```
+ *
+ * Here we calculate `f` as having dependencies `external, `local` and save
+ * this into `temporaries`. We then also immediately take these as dependencies
+ * at the Component scope, at which point we filter out `local` as a local variable,
+ * leaving just a dependency on `external`.
+ *
+ * When calling this function on a top-level component or hook, the collected dependencies
+ * will only contain the globals that it accesses which isn't useful. Instead, passing
+ * onStartMemoize/onFinishMemoize callbacks allows looking at the dependencies within
+ * blocks of manual memoization.
+ */
+function collectDependencies(
+  fn: HIRFunction,
+  temporaries: Map<IdentifierId, Temporary>,
+  callbacks: {
+    onStartMemoize: (
+      startMemo: StartMemoize,
+      dependencies: Set<InferredDependency>,
+      locals: Set<IdentifierId>,
+    ) => void;
+    onFinishMemoize: (
+      finishMemo: FinishMemoize,
+      dependencies: Set<InferredDependency>,
+      locals: Set<IdentifierId>,
+    ) => void;
+  } | null,
+  isFunctionExpression: boolean,
+): Extract<Temporary, {kind: 'Function'}> {
+  const optionals = findOptionalPlaces(fn);
+  if (DEBUG) {
+    console.log(prettyFormat(optionals));
+  }
+  const locals: Set<IdentifierId> = new Set();
+  if (isFunctionExpression) {
+    for (const param of fn.params) {
+      const place = param.kind === 'Identifier' ? param : param.place;
+      locals.add(place.identifier.id);
+    }
+  }
+
+  const dependencies: Set<InferredDependency> = new Set();
+  function visit(place: Place): void {
+    visitCandidateDependency(place, temporaries, dependencies, locals);
+  }
+  for (const block of fn.body.blocks.values()) {
+    for (const phi of block.phis) {
+      let deps: Array<Temporary> | null = null;
+      for (const operand of phi.operands.values()) {
+        const dep = temporaries.get(operand.identifier.id);
+        if (dep == null) {
+          continue;
+        }
+        if (deps == null) {
+          deps = [dep];
+        } else {
+          deps.push(dep);
+        }
+      }
+      if (deps == null) {
+        continue;
+      } else if (deps.length === 1) {
+        temporaries.set(phi.place.identifier.id, deps[0]!);
+      } else {
+        temporaries.set(phi.place.identifier.id, {
+          kind: 'Function',
+          dependencies: new Set(deps),
+        });
+      }
+    }
+
+    for (const instr of block.instructions) {
+      const {lvalue, value} = instr;
+      switch (value.kind) {
+        case 'LoadGlobal': {
+          temporaries.set(lvalue.identifier.id, {
+            kind: 'Global',
+            binding: value.binding,
+          });
+          break;
+        }
+        case 'LoadContext':
+        case 'LoadLocal': {
+          if (locals.has(value.place.identifier.id)) {
+            break;
+          }
+          const temp = temporaries.get(value.place.identifier.id);
+          if (temp != null) {
+            if (temp.kind === 'Local') {
+              const local: Temporary = {...temp, loc: value.place.loc};
+              temporaries.set(lvalue.identifier.id, local);
+            } else {
+              temporaries.set(lvalue.identifier.id, temp);
+            }
+          }
+          break;
+        }
+        case 'DeclareLocal': {
+          const local: Temporary = {
+            kind: 'Local',
+            identifier: value.lvalue.place.identifier,
+            path: [],
+            context: false,
+            loc: value.lvalue.place.loc,
+          };
+          temporaries.set(value.lvalue.place.identifier.id, local);
+          locals.add(value.lvalue.place.identifier.id);
+          break;
+        }
+        case 'StoreLocal': {
+          if (value.lvalue.place.identifier.name == null) {
+            const temp = temporaries.get(value.value.identifier.id);
+            if (temp != null) {
+              temporaries.set(value.lvalue.place.identifier.id, temp);
+            }
+            break;
+          }
+          visit(value.value);
+          if (value.lvalue.kind !== InstructionKind.Reassign) {
+            const local: Temporary = {
+              kind: 'Local',
+              identifier: value.lvalue.place.identifier,
+              path: [],
+              context: false,
+              loc: value.lvalue.place.loc,
+            };
+            temporaries.set(value.lvalue.place.identifier.id, local);
+            locals.add(value.lvalue.place.identifier.id);
+          }
+          break;
+        }
+        case 'DeclareContext': {
+          const local: Temporary = {
+            kind: 'Local',
+            identifier: value.lvalue.place.identifier,
+            path: [],
+            context: true,
+            loc: value.lvalue.place.loc,
+          };
+          temporaries.set(value.lvalue.place.identifier.id, local);
+          break;
+        }
+        case 'StoreContext': {
+          visit(value.value);
+          if (value.lvalue.kind !== InstructionKind.Reassign) {
+            const local: Temporary = {
+              kind: 'Local',
+              identifier: value.lvalue.place.identifier,
+              path: [],
+              context: true,
+              loc: value.lvalue.place.loc,
+            };
+            temporaries.set(value.lvalue.place.identifier.id, local);
+            locals.add(value.lvalue.place.identifier.id);
+          }
+          break;
+        }
+        case 'Destructure': {
+          visit(value.value);
+          if (value.lvalue.kind !== InstructionKind.Reassign) {
+            for (const lvalue of eachInstructionValueLValue(value)) {
+              const local: Temporary = {
+                kind: 'Local',
+                identifier: lvalue.identifier,
+                path: [],
+                context: false,
+                loc: lvalue.loc,
+              };
+              temporaries.set(lvalue.identifier.id, local);
+              locals.add(lvalue.identifier.id);
+            }
+          }
+          break;
+        }
+        case 'PropertyLoad': {
+          if (
+            typeof value.property === 'number' ||
+            (isUseRefType(value.object.identifier) &&
+              value.property === 'current')
+          ) {
+            visit(value.object);
+            break;
+          }
+          const object = temporaries.get(value.object.identifier.id);
+          if (object != null && object.kind === 'Local') {
+            const optional = optionals.get(value.object.identifier.id) ?? false;
+            const local: Temporary = {
+              kind: 'Local',
+              identifier: object.identifier,
+              context: object.context,
+              path: [
+                ...object.path,
+                {
+                  optional,
+                  property: value.property,
+                },
+              ],
+              loc: value.loc,
+            };
+            temporaries.set(lvalue.identifier.id, local);
+          }
+          break;
+        }
+        case 'FunctionExpression':
+        case 'ObjectMethod': {
+          const functionDeps = collectDependencies(
+            value.loweredFunc.func,
+            temporaries,
+            null,
+            true, // isFunctionExpression
+          );
+          temporaries.set(lvalue.identifier.id, functionDeps);
+          addDependency(functionDeps, dependencies, locals);
+          break;
+        }
+        case 'StartMemoize': {
+          const onStartMemoize = callbacks?.onStartMemoize;
+          if (onStartMemoize != null) {
+            onStartMemoize(value, dependencies, locals);
+          }
+          break;
+        }
+        case 'FinishMemoize': {
+          const onFinishMemoize = callbacks?.onFinishMemoize;
+          if (onFinishMemoize != null) {
+            onFinishMemoize(value, dependencies, locals);
+          }
+          break;
+        }
+        case 'MethodCall': {
+          // Ignore the method itself
+          for (const operand of eachInstructionValueOperand(value)) {
+            if (operand.identifier.id === value.property.identifier.id) {
+              continue;
+            }
+            visit(operand);
+          }
+          break;
+        }
+        default: {
+          for (const operand of eachInstructionValueOperand(value)) {
+            visit(operand);
+          }
+          for (const lvalue of eachInstructionLValue(instr)) {
+            locals.add(lvalue.identifier.id);
+          }
+        }
+      }
+    }
+    for (const operand of eachTerminalOperand(block.terminal)) {
+      if (optionals.has(operand.identifier.id)) {
+        continue;
+      }
+      visit(operand);
+    }
+  }
+  return {kind: 'Function', dependencies};
+}
+
+function printInferredDependency(dep: InferredDependency): string {
+  switch (dep.kind) {
+    case 'Global': {
+      return dep.binding.name;
+    }
+    case 'Local': {
+      CompilerError.simpleInvariant(
+        dep.identifier.name != null && dep.identifier.name.kind === 'named',
+        {
+          reason: 'Expected dependencies to be named variables',
+          loc: dep.loc,
+        },
+      );
+      return `${dep.identifier.name.value}${dep.path.map(p => (p.optional ? '?' : '') + '.' + p.property).join('')}`;
+    }
+  }
+}
+
+function printManualMemoDependency(dep: ManualMemoDependency): string {
+  let identifierName: string;
+  if (dep.root.kind === 'Global') {
+    identifierName = dep.root.identifierName;
+  } else {
+    const name = dep.root.value.identifier.name;
+    CompilerError.simpleInvariant(name != null && name.kind === 'named', {
+      reason: 'Expected manual dependencies to be named variables',
+      loc: dep.root.value.loc,
+    });
+    identifierName = name.value;
+  }
+  return `${identifierName}${dep.path.map(p => (p.optional ? '?' : '') + '.' + p.property).join('')}`;
+}
+
+function isEqualTemporary(a: Temporary, b: Temporary): boolean {
+  switch (a.kind) {
+    case 'Function': {
+      return false;
+    }
+    case 'Global': {
+      return b.kind === 'Global' && a.binding.name === b.binding.name;
+    }
+    case 'Local': {
+      return (
+        b.kind === 'Local' &&
+        a.identifier.id === b.identifier.id &&
+        areEqualPaths(a.path, b.path)
+      );
+    }
+  }
+}
+
+type Temporary =
+  | {kind: 'Global'; binding: LoadGlobal['binding']}
+  | {
+      kind: 'Local';
+      identifier: Identifier;
+      path: DependencyPath;
+      context: boolean;
+      loc: SourceLocation;
+    }
+  | {kind: 'Function'; dependencies: Set<Temporary>};
+type InferredDependency = Extract<Temporary, {kind: 'Local' | 'Global'}>;
+
+function collectReactiveIdentifiersHIR(fn: HIRFunction): Set<IdentifierId> {
+  const reactive = new Set<IdentifierId>();
+  for (const block of fn.body.blocks.values()) {
+    for (const instr of block.instructions) {
+      for (const lvalue of eachInstructionLValue(instr)) {
+        if (lvalue.reactive) {
+          reactive.add(lvalue.identifier.id);
+        }
+      }
+      for (const operand of eachInstructionValueOperand(instr.value)) {
+        if (operand.reactive) {
+          reactive.add(operand.identifier.id);
+        }
+      }
+    }
+    for (const operand of eachTerminalOperand(block.terminal)) {
+      if (operand.reactive) {
+        reactive.add(operand.identifier.id);
+      }
+    }
+  }
+  return reactive;
+}
+
+export function findOptionalPlaces(
+  fn: HIRFunction,
+): Map<IdentifierId, boolean> {
+  const optionals = new Map<IdentifierId, boolean>();
+  const visited: Set<BlockId> = new Set();
+  for (const [, block] of fn.body.blocks) {
+    if (visited.has(block.id)) {
+      continue;
+    }
+    if (block.terminal.kind === 'optional') {
+      visited.add(block.id);
+      const optionalTerminal = block.terminal;
+      let testBlock = fn.body.blocks.get(block.terminal.test)!;
+      const queue: Array<boolean | null> = [block.terminal.optional];
+      loop: while (true) {
+        visited.add(testBlock.id);
+        const terminal = testBlock.terminal;
+        switch (terminal.kind) {
+          case 'branch': {
+            const isOptional = queue.pop();
+            CompilerError.simpleInvariant(isOptional !== undefined, {
+              reason:
+                'Expected an optional value for each optional test condition',
+              loc: terminal.test.loc,
+            });
+            if (isOptional != null) {
+              optionals.set(terminal.test.identifier.id, isOptional);
+            }
+            if (terminal.fallthrough === optionalTerminal.fallthrough) {
+              // found it
+              const consequent = fn.body.blocks.get(terminal.consequent)!;
+              const last = consequent.instructions.at(-1);
+              if (last !== undefined && last.value.kind === 'StoreLocal') {
+                if (isOptional != null) {
+                  optionals.set(last.value.value.identifier.id, isOptional);
+                }
+              }
+              break loop;
+            } else {
+              testBlock = fn.body.blocks.get(terminal.fallthrough)!;
+            }
+            break;
+          }
+          case 'optional': {
+            queue.push(terminal.optional);
+            testBlock = fn.body.blocks.get(terminal.test)!;
+            break;
+          }
+          case 'logical':
+          case 'ternary': {
+            queue.push(null);
+            testBlock = fn.body.blocks.get(terminal.test)!;
+            break;
+          }
+
+          case 'sequence': {
+            // Do we need sequence?? In any case, don't push to queue bc there is no corresponding branch terminal
+            testBlock = fn.body.blocks.get(terminal.block)!;
+            break;
+          }
+          default: {
+            CompilerError.simpleInvariant(false, {
+              reason: `Unexpected terminal in optional`,
+              loc: terminal.loc,
+            });
+          }
+        }
+      }
+      CompilerError.simpleInvariant(queue.length === 0, {
+        reason:
+          'Expected a matching number of conditional blocks and branch points',
+        loc: block.terminal.loc,
+      });
+    }
+  }
+  return optionals;
+}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/compile-files-with-exhaustive-deps-violation-in-effects.expect.md

@@ -0,0 +1,91 @@
+
+## Input
+
+```javascript
+// @validateExhaustiveMemoizationDependencies
+
+import {useMemo} from 'react';
+import {ValidateMemoization} from 'shared-runtime';
+
+function Component({x}) {
+  useEffect(
+    () => {
+      console.log(x);
+      // eslint-disable-next-line react-hooks/exhaustive-deps
+    },
+    [
+      /* intentionally missing deps */
+    ]
+  );
+
+  const memo = useMemo(() => {
+    return [x];
+  }, [x]);
+
+  return <ValidateMemoization inputs={[x]} output={memo} />;
+}
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime"; // @validateExhaustiveMemoizationDependencies
+
+import { useMemo } from "react";
+import { ValidateMemoization } from "shared-runtime";
+
+function Component(t0) {
+  const $ = _c(10);
+  const { x } = t0;
+  let t1;
+  if ($[0] !== x) {
+    t1 = () => {
+      console.log(x);
+    };
+    $[0] = x;
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  let t2;
+  if ($[2] === Symbol.for("react.memo_cache_sentinel")) {
+    t2 = [];
+    $[2] = t2;
+  } else {
+    t2 = $[2];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[3] !== x) {
+    t3 = [x];
+    $[3] = x;
+    $[4] = t3;
+  } else {
+    t3 = $[4];
+  }
+  const memo = t3;
+  let t4;
+  if ($[5] !== x) {
+    t4 = [x];
+    $[5] = x;
+    $[6] = t4;
+  } else {
+    t4 = $[6];
+  }
+  let t5;
+  if ($[7] !== memo || $[8] !== t4) {
+    t5 = <ValidateMemoization inputs={t4} output={memo} />;
+    $[7] = memo;
+    $[8] = t4;
+    $[9] = t5;
+  } else {
+    t5 = $[9];
+  }
+  return t5;
+}
+
+```
+      
+### Eval output
+(kind: exception) Fixture not implemented

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/compile-files-with-exhaustive-deps-violation-in-effects.js

@@ -0,0 +1,22 @@
+// @validateExhaustiveMemoizationDependencies
+
+import {useMemo} from 'react';
+import {ValidateMemoization} from 'shared-runtime';
+
+function Component({x}) {
+  useEffect(
+    () => {
+      console.log(x);
+      // eslint-disable-next-line react-hooks/exhaustive-deps
+    },
+    [
+      /* intentionally missing deps */
+    ]
+  );
+
+  const memo = useMemo(() => {
+    return [x];
+  }, [x]);
+
+  return <ValidateMemoization inputs={[x]} output={memo} />;
+}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-exhaustive-deps.expect.md

@@ -0,0 +1,109 @@
+
+## Input
+
+```javascript
+// @validateExhaustiveMemoizationDependencies
+import {useMemo} from 'react';
+import {Stringify} from 'shared-runtime';
+
+function Component({x, y, z}) {
+  const a = useMemo(() => {
+    return x?.y.z?.a;
+    // error: too precise
+  }, [x?.y.z?.a.b]);
+  const b = useMemo(() => {
+    return x.y.z?.a;
+    // ok, not our job to type check nullability
+  }, [x.y.z.a]);
+  const c = useMemo(() => {
+    return x?.y.z.a?.b;
+    // error: too precise
+  }, [x?.y.z.a?.b.z]);
+  const d = useMemo(() => {
+    return x?.y?.[(console.log(y), z?.b)];
+    // ok
+  }, [x?.y, y, z?.b]);
+  const e = useMemo(() => {
+    const e = [];
+    e.push(x);
+    return e;
+    // ok
+  }, [x]);
+  const f = useMemo(() => {
+    return [];
+    // error: unnecessary
+  }, [x, y.z, z?.y?.a, UNUSED_GLOBAL]);
+  const ref1 = useRef(null);
+  const ref2 = useRef(null);
+  const ref = z ? ref1 : ref2;
+  const cb = useMemo(() => {
+    return () => {
+      return ref.current;
+    };
+    // error: ref is a stable type but reactive
+  }, []);
+  return <Stringify results={[a, b, c, d, e, f, cb]} />;
+}
+
+```
+
+
+## Error
+
+```
+Found 4 errors:
+
+Error: Found missing memoization dependencies
+
+Missing dependencies can cause a value not to update when those inputs change, resulting in stale UI.
+
+error.invalid-exhaustive-deps.ts:7:11
+   5 | function Component({x, y, z}) {
+   6 |   const a = useMemo(() => {
+>  7 |     return x?.y.z?.a;
+     |            ^^^^^^^^^ Missing dependency `x?.y.z?.a`
+   8 |     // error: too precise
+   9 |   }, [x?.y.z?.a.b]);
+  10 |   const b = useMemo(() => {
+
+Error: Found missing memoization dependencies
+
+Missing dependencies can cause a value not to update when those inputs change, resulting in stale UI.
+
+error.invalid-exhaustive-deps.ts:15:11
+  13 |   }, [x.y.z.a]);
+  14 |   const c = useMemo(() => {
+> 15 |     return x?.y.z.a?.b;
+     |            ^^^^^^^^^^^ Missing dependency `x?.y.z.a?.b`
+  16 |     // error: too precise
+  17 |   }, [x?.y.z.a?.b.z]);
+  18 |   const d = useMemo(() => {
+
+Error: Found unnecessary memoization dependencies
+
+Unnecessary dependencies can cause a value to update more often than necessary, causing performance regressions and effects to fire more often than expected.
+
+error.invalid-exhaustive-deps.ts:31:5
+  29 |     return [];
+  30 |     // error: unnecessary
+> 31 |   }, [x, y.z, z?.y?.a, UNUSED_GLOBAL]);
+     |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Unnecessary dependencies `x`, `y.z`, `z?.y?.a`, `UNUSED_GLOBAL`
+  32 |   const ref1 = useRef(null);
+  33 |   const ref2 = useRef(null);
+  34 |   const ref = z ? ref1 : ref2;
+
+Error: Found missing memoization dependencies
+
+Missing dependencies can cause a value not to update when those inputs change, resulting in stale UI.
+
+error.invalid-exhaustive-deps.ts:37:13
+  35 |   const cb = useMemo(() => {
+  36 |     return () => {
+> 37 |       return ref.current;
+     |              ^^^ Missing dependency `ref`. Refs, setState functions, and other "stable" values generally do not need to be added as dependencies, but this variable may change over time to point to different values
+  38 |     };
+  39 |     // error: ref is a stable type but reactive
+  40 |   }, []);
+```
+          
+      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-exhaustive-deps.js

@@ -0,0 +1,42 @@
+// @validateExhaustiveMemoizationDependencies
+import {useMemo} from 'react';
+import {Stringify} from 'shared-runtime';
+
+function Component({x, y, z}) {
+  const a = useMemo(() => {
+    return x?.y.z?.a;
+    // error: too precise
+  }, [x?.y.z?.a.b]);
+  const b = useMemo(() => {
+    return x.y.z?.a;
+    // ok, not our job to type check nullability
+  }, [x.y.z.a]);
+  const c = useMemo(() => {
+    return x?.y.z.a?.b;
+    // error: too precise
+  }, [x?.y.z.a?.b.z]);
+  const d = useMemo(() => {
+    return x?.y?.[(console.log(y), z?.b)];
+    // ok
+  }, [x?.y, y, z?.b]);
+  const e = useMemo(() => {
+    const e = [];
+    e.push(x);
+    return e;
+    // ok
+  }, [x]);
+  const f = useMemo(() => {
+    return [];
+    // error: unnecessary
+  }, [x, y.z, z?.y?.a, UNUSED_GLOBAL]);
+  const ref1 = useRef(null);
+  const ref2 = useRef(null);
+  const ref = z ? ref1 : ref2;
+  const cb = useMemo(() => {
+    return () => {
+      return ref.current;
+    };
+    // error: ref is a stable type but reactive
+  }, []);
+  return <Stringify results={[a, b, c, d, e, f, cb]} />;
+}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/exhaustive-deps-allow-nonreactive-stable-types-as-extra-deps.expect.md

@@ -0,0 +1,100 @@
+
+## Input
+
+```javascript
+// @validateExhaustiveMemoizationDependencies
+import {
+  useCallback,
+  useTransition,
+  useState,
+  useOptimistic,
+  useActionState,
+  useRef,
+  useReducer,
+} from 'react';
+
+function useFoo() {
+  const [s, setState] = useState();
+  const ref = useRef(null);
+  const [t, startTransition] = useTransition();
+  const [u, addOptimistic] = useOptimistic();
+  const [v, dispatch] = useReducer(() => {}, null);
+  const [isPending, dispatchAction] = useActionState(() => {}, null);
+
+  return useCallback(() => {
+    dispatch();
+    startTransition(() => {});
+    addOptimistic();
+    setState(null);
+    dispatchAction();
+    ref.current = true;
+  }, [
+    // intentionally adding unnecessary deps on nonreactive stable values
+    // to check that they're allowed
+    dispatch,
+    startTransition,
+    addOptimistic,
+    setState,
+    dispatchAction,
+    ref,
+  ]);
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useFoo,
+  params: [],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime"; // @validateExhaustiveMemoizationDependencies
+import {
+  useCallback,
+  useTransition,
+  useState,
+  useOptimistic,
+  useActionState,
+  useRef,
+  useReducer,
+} from "react";
+
+function useFoo() {
+  const $ = _c(1);
+  const [, setState] = useState();
+  const ref = useRef(null);
+  const [, startTransition] = useTransition();
+  const [, addOptimistic] = useOptimistic();
+  const [, dispatch] = useReducer(_temp, null);
+  const [, dispatchAction] = useActionState(_temp2, null);
+  let t0;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    t0 = () => {
+      dispatch();
+      startTransition(_temp3);
+      addOptimistic();
+      setState(null);
+      dispatchAction();
+      ref.current = true;
+    };
+    $[0] = t0;
+  } else {
+    t0 = $[0];
+  }
+  return t0;
+}
+function _temp3() {}
+function _temp2() {}
+function _temp() {}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useFoo,
+  params: [],
+};
+
+```
+      
+### Eval output
+(kind: ok) "[[ function params=0 ]]"

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/exhaustive-deps-allow-nonreactive-stable-types-as-extra-deps.js

@@ -0,0 +1,42 @@
+// @validateExhaustiveMemoizationDependencies
+import {
+  useCallback,
+  useTransition,
+  useState,
+  useOptimistic,
+  useActionState,
+  useRef,
+  useReducer,
+} from 'react';
+
+function useFoo() {
+  const [s, setState] = useState();
+  const ref = useRef(null);
+  const [t, startTransition] = useTransition();
+  const [u, addOptimistic] = useOptimistic();
+  const [v, dispatch] = useReducer(() => {}, null);
+  const [isPending, dispatchAction] = useActionState(() => {}, null);
+
+  return useCallback(() => {
+    dispatch();
+    startTransition(() => {});
+    addOptimistic();
+    setState(null);
+    dispatchAction();
+    ref.current = true;
+  }, [
+    // intentionally adding unnecessary deps on nonreactive stable values
+    // to check that they're allowed
+    dispatch,
+    startTransition,
+    addOptimistic,
+    setState,
+    dispatchAction,
+    ref,
+  ]);
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useFoo,
+  params: [],
+};

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

@@ -0,0 +1,201 @@
+
+## Input
+
+```javascript
+// @validateExhaustiveMemoizationDependencies
+import {useCallback, useMemo} from 'react';
+import {makeObject_Primitives, Stringify} from 'shared-runtime';
+
+function useHook1(x) {
+  return useMemo(() => {
+    return x?.y.z?.a;
+  }, [x?.y.z?.a]);
+}
+function useHook2(x) {
+  useMemo(() => {
+    return x.y.z?.a;
+  }, [x.y.z?.a]);
+}
+function useHook3(x) {
+  return useMemo(() => {
+    return x?.y.z.a?.b;
+  }, [x?.y.z.a?.b]);
+}
+function useHook4(x, y, z) {
+  return useMemo(() => {
+    return x?.y?.[(console.log(y), z?.b)];
+  }, [x?.y, y, z?.b]);
+}
+function useHook5(x) {
+  return useMemo(() => {
+    const e = [];
+    const local = makeObject_Primitives(x);
+    const fn = () => {
+      e.push(local);
+    };
+    fn();
+    return e;
+  }, [x]);
+}
+function useHook6(x) {
+  return useMemo(() => {
+    const f = [];
+    f.push(x.y.z);
+    f.push(x.y);
+    f.push(x);
+    return f;
+  }, [x]);
+}
+
+function useHook7(x) {
+  const [state, setState] = useState(true);
+  const f = () => {
+    setState(x => !x);
+  };
+  return useCallback(() => {
+    f();
+  }, [f]);
+}
+
+function Component({x, y, z}) {
+  const a = useHook1(x);
+  const b = useHook2(x);
+  const c = useHook3(x);
+  const d = useHook4(x, y, z);
+  const e = useHook5(x);
+  const f = useHook6(x);
+  const g = useHook7(x);
+  return <Stringify results={[a, b, c, d, e, f, g]} />;
+}
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime"; // @validateExhaustiveMemoizationDependencies
+import { useCallback, useMemo } from "react";
+import { makeObject_Primitives, Stringify } from "shared-runtime";
+
+function useHook1(x) {
+  x?.y.z?.a;
+  return x?.y.z?.a;
+}
+
+function useHook2(x) {
+  x.y.z?.a;
+}
+
+function useHook3(x) {
+  x?.y.z.a?.b;
+  return x?.y.z.a?.b;
+}
+
+function useHook4(x, y, z) {
+  x?.y;
+  z?.b;
+  return x?.y?.[(console.log(y), z?.b)];
+}
+
+function useHook5(x) {
+  const $ = _c(2);
+  let e;
+  if ($[0] !== x) {
+    e = [];
+    const local = makeObject_Primitives(x);
+    const fn = () => {
+      e.push(local);
+    };
+
+    fn();
+    $[0] = x;
+    $[1] = e;
+  } else {
+    e = $[1];
+  }
+  return e;
+}
+
+function useHook6(x) {
+  const $ = _c(2);
+  let f;
+  if ($[0] !== x) {
+    f = [];
+    f.push(x.y.z);
+    f.push(x.y);
+    f.push(x);
+    $[0] = x;
+    $[1] = f;
+  } else {
+    f = $[1];
+  }
+  return f;
+}
+
+function useHook7(x) {
+  const $ = _c(2);
+  const [, setState] = useState(true);
+  let t0;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    t0 = () => {
+      setState(_temp);
+    };
+    $[0] = t0;
+  } else {
+    t0 = $[0];
+  }
+  const f = t0;
+  let t1;
+  if ($[1] === Symbol.for("react.memo_cache_sentinel")) {
+    t1 = () => {
+      f();
+    };
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  return t1;
+}
+function _temp(x_0) {
+  return !x_0;
+}
+
+function Component(t0) {
+  const $ = _c(8);
+  const { x, y, z } = t0;
+  const a = useHook1(x);
+  const b = useHook2(x);
+  const c = useHook3(x);
+  const d = useHook4(x, y, z);
+  const e = useHook5(x);
+  const f = useHook6(x);
+  const g = useHook7(x);
+  let t1;
+  if (
+    $[0] !== a ||
+    $[1] !== b ||
+    $[2] !== c ||
+    $[3] !== d ||
+    $[4] !== e ||
+    $[5] !== f ||
+    $[6] !== g
+  ) {
+    t1 = <Stringify results={[a, b, c, d, e, f, g]} />;
+    $[0] = a;
+    $[1] = b;
+    $[2] = c;
+    $[3] = d;
+    $[4] = e;
+    $[5] = f;
+    $[6] = g;
+    $[7] = t1;
+  } else {
+    t1 = $[7];
+  }
+  return t1;
+}
+
+```
+      
+### Eval output
+(kind: exception) Fixture not implemented

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/exhaustive-deps.js

@@ -0,0 +1,65 @@
+// @validateExhaustiveMemoizationDependencies
+import {useCallback, useMemo} from 'react';
+import {makeObject_Primitives, Stringify} from 'shared-runtime';
+
+function useHook1(x) {
+  return useMemo(() => {
+    return x?.y.z?.a;
+  }, [x?.y.z?.a]);
+}
+function useHook2(x) {
+  useMemo(() => {
+    return x.y.z?.a;
+  }, [x.y.z?.a]);
+}
+function useHook3(x) {
+  return useMemo(() => {
+    return x?.y.z.a?.b;
+  }, [x?.y.z.a?.b]);
+}
+function useHook4(x, y, z) {
+  return useMemo(() => {
+    return x?.y?.[(console.log(y), z?.b)];
+  }, [x?.y, y, z?.b]);
+}
+function useHook5(x) {
+  return useMemo(() => {
+    const e = [];
+    const local = makeObject_Primitives(x);
+    const fn = () => {
+      e.push(local);
+    };
+    fn();
+    return e;
+  }, [x]);
+}
+function useHook6(x) {
+  return useMemo(() => {
+    const f = [];
+    f.push(x.y.z);
+    f.push(x.y);
+    f.push(x);
+    return f;
+  }, [x]);
+}
+
+function useHook7(x) {
+  const [state, setState] = useState(true);
+  const f = () => {
+    setState(x => !x);
+  };
+  return useCallback(() => {
+    f();
+  }, [f]);
+}
+
+function Component({x, y, z}) {
+  const a = useHook1(x);
+  const b = useHook2(x);
+  const c = useHook3(x);
+  const d = useHook4(x, y, z);
+  const e = useHook5(x);
+  const f = useHook6(x);
+  const g = useHook7(x);
+  return <Stringify results={[a, b, c, d, e, f, g]} />;
+}

compiler/packages/snap/src/runner.ts

@@ -53,8 +53,10 @@ const opts: RunnerOptions = yargs
   .default('worker-threads', true)
   .boolean('watch')
   .describe('watch', 'Run compiler in watch mode, re-running after changes')
+  .alias('w', 'watch')
   .default('watch', false)
   .boolean('update')
+  .alias('u', 'update')
   .describe('update', 'Update fixtures')
   .default('update', false)
   .boolean('filter')

packages/react-devtools-shared/src/__tests__/profilerContext-test.js

@@ -584,4 +584,75 @@ describe('ProfilerContext', () => {
     await utils.actAsync(() => context.selectFiber(childID, 'Child'));
     expect(inspectedElementID).toBe(parentID);
   });
+
+  it('should toggle profiling when the keyboard shortcut is pressed', async () => {
+    // Context providers
+    const Profiler =
+      require('react-devtools-shared/src/devtools/views/Profiler/Profiler').default;
+    const {
+      TimelineContextController,
+    } = require('react-devtools-timeline/src/TimelineContext');
+    const {
+      SettingsContextController,
+    } = require('react-devtools-shared/src/devtools/views/Settings/SettingsContext');
+    const {
+      ModalDialogContextController,
+    } = require('react-devtools-shared/src/devtools/views/ModalDialog');
+
+    // Dom component for profiling to be enabled
+    const Component = () => null;
+    utils.act(() => render(<Component />));
+
+    const profilerContainer = document.createElement('div');
+    document.body.appendChild(profilerContainer);
+
+    // Create a root for the profiler
+    const profilerRoot = ReactDOMClient.createRoot(profilerContainer);
+
+    // Render the profiler
+    utils.act(() => {
+      profilerRoot.render(
+        <Contexts>
+          <SettingsContextController browserTheme="light">
+            <ModalDialogContextController>
+              <TimelineContextController>
+                <Profiler />
+              </TimelineContextController>
+            </ModalDialogContextController>
+          </SettingsContextController>
+        </Contexts>,
+      );
+    });
+
+    // Verify that the profiler is not profiling.
+    expect(store.profilerStore.isProfilingBasedOnUserInput).toBe(false);
+
+    // Trigger the keyboard shortcut.
+    const ownerWindow = profilerContainer.ownerDocument.defaultView;
+    const isMac =
+      typeof navigator !== 'undefined' &&
+      navigator.platform.toUpperCase().indexOf('MAC') >= 0;
+
+    const keyEvent = new KeyboardEvent('keydown', {
+      key: 'e',
+      metaKey: isMac,
+      ctrlKey: !isMac,
+      bubbles: true,
+    });
+
+    // Dispatch keyboard event to toggle profiling on
+    // Try utils.actAsync with recursivelyFlush=false
+    await utils.actAsync(() => {
+      ownerWindow.dispatchEvent(keyEvent);
+    }, false);
+    expect(store.profilerStore.isProfilingBasedOnUserInput).toBe(true);
+
+    // Dispatch keyboard event to toggle profiling off
+    await utils.actAsync(() => {
+      ownerWindow.dispatchEvent(keyEvent);
+    }, false);
+    expect(store.profilerStore.isProfilingBasedOnUserInput).toBe(false);
+
+    document.body.removeChild(profilerContainer);
+  });
 });

packages/react-devtools-shared/src/devtools/views/Profiler/Profiler.js

@@ -8,7 +8,7 @@
  */
 
 import * as React from 'react';
-import {Fragment, useContext} from 'react';
+import {Fragment, useContext, useEffect, useRef, useEffectEvent} from 'react';
 import {ModalDialog} from '../ModalDialog';
 import {ProfilerContext} from './ProfilerContext';
 import TabBar from '../TabBar';
@@ -38,6 +38,11 @@ import {TimelineContext} from 'react-devtools-timeline/src/TimelineContext';
 import styles from './Profiler.css';
 
 function Profiler(_: {}) {
+  const profilerRef = useRef<HTMLDivElement | null>(null);
+  const isMac =
+    typeof navigator !== 'undefined' &&
+    navigator.platform.toUpperCase().indexOf('MAC') >= 0;
+
   const {
     didRecordCommits,
     isProcessingData,
@@ -47,6 +52,8 @@ function Profiler(_: {}) {
     selectedTabID,
     selectTab,
     supportsProfiling,
+    startProfiling,
+    stopProfiling,
   } = useContext(ProfilerContext);
 
   const {file: timelineTraceEventData, searchInputContainerRef} =
@@ -56,6 +63,32 @@ function Profiler(_: {}) {
 
   const isLegacyProfilerSelected = selectedTabID !== 'timeline';
 
+  // Cmd+E to start/stop profiler recording
+  const handleKeyDown = useEffectEvent((event: KeyboardEvent) => {
+    const correctModifier = isMac ? event.metaKey : event.ctrlKey;
+    if (correctModifier && event.key === 'e') {
+      if (isProfiling) {
+        stopProfiling();
+      } else {
+        startProfiling();
+      }
+      event.preventDefault();
+      event.stopPropagation();
+    }
+  });
+
+  useEffect(() => {
+    const div = profilerRef.current;
+    if (!div) {
+      return;
+    }
+    const ownerWindow = div.ownerDocument.defaultView;
+    ownerWindow.addEventListener('keydown', handleKeyDown);
+    return () => {
+      ownerWindow.removeEventListener('keydown', handleKeyDown);
+    };
+  }, []);
+
   let view = null;
   if (didRecordCommits || selectedTabID === 'timeline') {
     switch (selectedTabID) {
@@ -112,7 +145,7 @@ function Profiler(_: {}) {
 
   return (
     <SettingsModalContextController>
-      <div className={styles.Profiler}>
+      <div ref={profilerRef} className={styles.Profiler}>
         <div className={styles.LeftColumn}>
           <div className={styles.Toolbar}>
             <RecordToggle disabled={!supportsProfiling} />

packages/react-devtools-shared/src/devtools/views/Profiler/RecordToggle.js

@@ -30,13 +30,19 @@ export default function RecordToggle({disabled}: Props): React.Node {
     className = styles.ActiveRecordToggle;
   }
 
+  const isMac =
+    typeof navigator !== 'undefined' &&
+    navigator.platform.toUpperCase().indexOf('MAC') >= 0;
+  const shortcut = isMac ? '⌘E' : 'Ctrl+E';
+  const title = `${isProfiling ? 'Stop' : 'Start'} profiling - ${shortcut}`;
+
   return (
     <Button
       className={className}
       disabled={disabled}
       onClick={isProfiling ? stopProfiling : startProfiling}
       testName="ProfilerToggleButton"
-      title={isProfiling ? 'Stop profiling' : 'Start profiling'}>
+      title={title}>
       <ButtonIcon type="record" />
     </Button>
   );