[compiler] fix false positive "mutate frozen" validation with refs

The test case here previously reported a "Cannot modify local variables after render completes" error (from ValidateNoFreezingKnownMutableFunctions). This happens because one of the functions passed to a hook clearly mutates a ref — except that we try to ignore mutations of refs! The problem in this case is that the `const ref = ...` was getting converted to a context variable since the ref is accessed in a function before its declaration. We don't infer types for context variables at all, and our ref handling is based on types, so we failed to ignore this ref mutation.

The fix is to recognize that `StoreLocal const ...` is a special case: the variable may be referenced in code before the declaration, but at runtime it's either a TDZ error or the variable will have the type from the declaration. So we can safely infer a type.

.eslintrc.js

@@ -608,7 +608,6 @@ module.exports = {
     symbol: 'readonly',
     SyntheticEvent: 'readonly',
     SyntheticMouseEvent: 'readonly',
-    SyntheticPointerEvent: 'readonly',
     Thenable: 'readonly',
     TimeoutID: 'readonly',
     WheelEventHandler: 'readonly',

CHANGELOG.md

@@ -1,8 +1,3 @@
-## 19.1.1 (July 28, 2025)
-
-### React
-* Fixed Owner Stacks to work with ES2015 function.name semantics ([#33680](https://github.com/facebook/react/pull/33680) by @hoxyq)
-
 ## 19.1.0 (March 28, 2025)
 
 ### Owner Stack

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

@@ -219,7 +219,6 @@ function compile(
               validateNoImpureFunctionsInRender: true,
               validateStaticComponents: true,
               validateNoFreezingKnownMutableFunctions: true,
-              validateNoVoidUseMemo: true,
             }
           : {
               /* use defaults for compiler mode */

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

@@ -58,15 +58,11 @@ export type CompilerDiagnosticDetail =
   /**
    * A/the source of the error
    */
-  | {
-      kind: 'error';
-      loc: SourceLocation | null;
-      message: string;
-    }
-  | {
-      kind: 'hint';
-      message: string;
-    };
+  {
+    kind: 'error';
+    loc: SourceLocation | null;
+    message: string;
+  };
 
 export enum CompilerSuggestionOperation {
   InsertBefore,
@@ -138,12 +134,7 @@ export class CompilerDiagnostic {
   }
 
   primaryLocation(): SourceLocation | null {
-    const firstErrorDetail = this.options.details.filter(
-      d => d.kind === 'error',
-    )[0];
-    return firstErrorDetail != null && firstErrorDetail.kind === 'error'
-      ? firstErrorDetail.loc
-      : null;
+    return this.options.details.filter(d => d.kind === 'error')[0]?.loc ?? null;
   }
 
   printErrorMessage(source: string, options: PrintErrorMessageOptions): string {
@@ -176,14 +167,9 @@ export class CompilerDiagnostic {
           buffer.push(codeFrame);
           break;
         }
-        case 'hint': {
-          buffer.push('\n\n');
-          buffer.push(detail.message);
-          break;
-        }
         default: {
           assertExhaustive(
-            detail,
+            detail.kind,
             `Unexpected detail kind ${(detail as any).kind}`,
           );
         }

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

@@ -92,6 +92,7 @@ import {
 } from '../Validation';
 import {validateLocalsNotReassignedAfterRender} from '../Validation/ValidateLocalsNotReassignedAfterRender';
 import {outlineFunctions} from '../Optimization/OutlineFunctions';
+import {propagatePhiTypes} from '../TypeInference/PropagatePhiTypes';
 import {lowerContextAccess} from '../Optimization/LowerContextAccess';
 import {validateNoSetStateInEffects} from '../Validation/ValidateNoSetStateInEffects';
 import {validateNoJSXInTryStatement} from '../Validation/ValidateNoJSXInTryStatement';
@@ -105,7 +106,6 @@ import {validateStaticComponents} from '../Validation/ValidateStaticComponents';
 import {validateNoFreezingKnownMutableFunctions} from '../Validation/ValidateNoFreezingKnownMutableFunctions';
 import {inferMutationAliasingEffects} from '../Inference/InferMutationAliasingEffects';
 import {inferMutationAliasingRanges} from '../Inference/InferMutationAliasingRanges';
-import {validateNoDerivedComputationsInEffects} from '../Validation/ValidateNoDerivedComputationsInEffects';
 
 export type CompilerPipelineValue =
   | {kind: 'ast'; name: string; value: CodegenFunction}
@@ -174,7 +174,7 @@ function runWithEnvironment(
     !env.config.disableMemoizationForDebugging &&
     !env.config.enableChangeDetectionForDebugging
   ) {
-    dropManualMemoization(hir).unwrap();
+    dropManualMemoization(hir);
     log({kind: 'hir', name: 'DropManualMemoization', value: hir});
   }
 
@@ -292,10 +292,6 @@ function runWithEnvironment(
       validateNoSetStateInRender(hir).unwrap();
     }
 
-    if (env.config.validateNoDerivedComputationsInEffects) {
-      validateNoDerivedComputationsInEffects(hir);
-    }
-
     if (env.config.validateNoSetStateInEffects) {
       env.logErrors(validateNoSetStateInEffects(hir));
     }
@@ -326,6 +322,13 @@ function runWithEnvironment(
     value: hir,
   });
 
+  propagatePhiTypes(hir);
+  log({
+    kind: 'hir',
+    name: 'PropagatePhiTypes',
+    value: hir,
+  });
+
   if (env.isInferredMemoEnabled) {
     if (env.config.validateStaticComponents) {
       env.logErrors(validateStaticComponents(hir));

compiler/packages/babel-plugin-react-compiler/src/Flood/FlowTypes.ts

@@ -1,752 +0,0 @@
-/**
- * TypeScript definitions for Flow type JSON representations
- * Based on the output of /data/sandcastle/boxes/fbsource/fbcode/flow/src/typing/convertTypes.ml
- */
-
-// Base type for all Flow types with a kind field
-export interface BaseFlowType {
-  kind: string;
-}
-
-// Type for representing polarity
-export type Polarity = 'positive' | 'negative' | 'neutral';
-
-// Type for representing a name that might be null
-export type OptionalName = string | null;
-
-// Open type
-export interface OpenType extends BaseFlowType {
-  kind: 'Open';
-}
-
-// Def type
-export interface DefType extends BaseFlowType {
-  kind: 'Def';
-  def: DefT;
-}
-
-// Eval type
-export interface EvalType extends BaseFlowType {
-  kind: 'Eval';
-  type: FlowType;
-  destructor: Destructor;
-}
-
-// Generic type
-export interface GenericType extends BaseFlowType {
-  kind: 'Generic';
-  name: string;
-  bound: FlowType;
-  no_infer: boolean;
-}
-
-// ThisInstance type
-export interface ThisInstanceType extends BaseFlowType {
-  kind: 'ThisInstance';
-  instance: InstanceT;
-  is_this: boolean;
-  name: string;
-}
-
-// ThisTypeApp type
-export interface ThisTypeAppType extends BaseFlowType {
-  kind: 'ThisTypeApp';
-  t1: FlowType;
-  t2: FlowType;
-  t_list?: Array<FlowType>;
-}
-
-// TypeApp type
-export interface TypeAppType extends BaseFlowType {
-  kind: 'TypeApp';
-  type: FlowType;
-  targs: Array<FlowType>;
-  from_value: boolean;
-  use_desc: boolean;
-}
-
-// FunProto type
-export interface FunProtoType extends BaseFlowType {
-  kind: 'FunProto';
-}
-
-// ObjProto type
-export interface ObjProtoType extends BaseFlowType {
-  kind: 'ObjProto';
-}
-
-// NullProto type
-export interface NullProtoType extends BaseFlowType {
-  kind: 'NullProto';
-}
-
-// FunProtoBind type
-export interface FunProtoBindType extends BaseFlowType {
-  kind: 'FunProtoBind';
-}
-
-// Intersection type
-export interface IntersectionType extends BaseFlowType {
-  kind: 'Intersection';
-  members: Array<FlowType>;
-}
-
-// Union type
-export interface UnionType extends BaseFlowType {
-  kind: 'Union';
-  members: Array<FlowType>;
-}
-
-// Maybe type
-export interface MaybeType extends BaseFlowType {
-  kind: 'Maybe';
-  type: FlowType;
-}
-
-// Optional type
-export interface OptionalType extends BaseFlowType {
-  kind: 'Optional';
-  type: FlowType;
-  use_desc: boolean;
-}
-
-// Keys type
-export interface KeysType extends BaseFlowType {
-  kind: 'Keys';
-  type: FlowType;
-}
-
-// Annot type
-export interface AnnotType extends BaseFlowType {
-  kind: 'Annot';
-  type: FlowType;
-  use_desc: boolean;
-}
-
-// Opaque type
-export interface OpaqueType extends BaseFlowType {
-  kind: 'Opaque';
-  opaquetype: {
-    opaque_id: string;
-    underlying_t: FlowType | null;
-    super_t: FlowType | null;
-    opaque_type_args: Array<{
-      name: string;
-      type: FlowType;
-      polarity: Polarity;
-    }>;
-    opaque_name: string;
-  };
-}
-
-// Namespace type
-export interface NamespaceType extends BaseFlowType {
-  kind: 'Namespace';
-  namespace_symbol: {
-    symbol: string;
-  };
-  values_type: FlowType;
-  types_tmap: PropertyMap;
-}
-
-// Any type
-export interface AnyType extends BaseFlowType {
-  kind: 'Any';
-}
-
-// StrUtil type
-export interface StrUtilType extends BaseFlowType {
-  kind: 'StrUtil';
-  op: 'StrPrefix' | 'StrSuffix';
-  prefix?: string;
-  suffix?: string;
-  remainder?: FlowType;
-}
-
-// TypeParam definition
-export interface TypeParam {
-  name: string;
-  bound: FlowType;
-  polarity: Polarity;
-  default: FlowType | null;
-}
-
-// EnumInfo types
-export type EnumInfo = ConcreteEnum | AbstractEnum;
-
-export interface ConcreteEnum {
-  kind: 'ConcreteEnum';
-  enum_name: string;
-  enum_id: string;
-  members: Array<string>;
-  representation_t: FlowType;
-  has_unknown_members: boolean;
-}
-
-export interface AbstractEnum {
-  kind: 'AbstractEnum';
-  representation_t: FlowType;
-}
-
-// CanonicalRendersForm types
-export type CanonicalRendersForm =
-  | InstrinsicRenders
-  | NominalRenders
-  | StructuralRenders
-  | DefaultRenders;
-
-export interface InstrinsicRenders {
-  kind: 'InstrinsicRenders';
-  name: string;
-}
-
-export interface NominalRenders {
-  kind: 'NominalRenders';
-  renders_id: string;
-  renders_name: string;
-  renders_super: FlowType;
-}
-
-export interface StructuralRenders {
-  kind: 'StructuralRenders';
-  renders_variant: 'RendersNormal' | 'RendersMaybe' | 'RendersStar';
-  renders_structural_type: FlowType;
-}
-
-export interface DefaultRenders {
-  kind: 'DefaultRenders';
-}
-
-// InstanceT definition
-export interface InstanceT {
-  inst: InstType;
-  static: FlowType;
-  super: FlowType;
-  implements: Array<FlowType>;
-}
-
-// InstType definition
-export interface InstType {
-  class_name: string | null;
-  class_id: string;
-  type_args: Array<{
-    name: string;
-    type: FlowType;
-    polarity: Polarity;
-  }>;
-  own_props: PropertyMap;
-  proto_props: PropertyMap;
-  call_t: null | {
-    id: number;
-    call: FlowType;
-  };
-}
-
-// DefT types
-export type DefT =
-  | NumGeneralType
-  | StrGeneralType
-  | BoolGeneralType
-  | BigIntGeneralType
-  | EmptyType
-  | MixedType
-  | NullType
-  | VoidType
-  | SymbolType
-  | FunType
-  | ObjType
-  | ArrType
-  | ClassType
-  | InstanceType
-  | SingletonStrType
-  | NumericStrKeyType
-  | SingletonNumType
-  | SingletonBoolType
-  | SingletonBigIntType
-  | TypeType
-  | PolyType
-  | ReactAbstractComponentType
-  | RendersType
-  | EnumValueType
-  | EnumObjectType;
-
-export interface NumGeneralType extends BaseFlowType {
-  kind: 'NumGeneral';
-}
-
-export interface StrGeneralType extends BaseFlowType {
-  kind: 'StrGeneral';
-}
-
-export interface BoolGeneralType extends BaseFlowType {
-  kind: 'BoolGeneral';
-}
-
-export interface BigIntGeneralType extends BaseFlowType {
-  kind: 'BigIntGeneral';
-}
-
-export interface EmptyType extends BaseFlowType {
-  kind: 'Empty';
-}
-
-export interface MixedType extends BaseFlowType {
-  kind: 'Mixed';
-}
-
-export interface NullType extends BaseFlowType {
-  kind: 'Null';
-}
-
-export interface VoidType extends BaseFlowType {
-  kind: 'Void';
-}
-
-export interface SymbolType extends BaseFlowType {
-  kind: 'Symbol';
-}
-
-export interface FunType extends BaseFlowType {
-  kind: 'Fun';
-  static: FlowType;
-  funtype: FunTypeObj;
-}
-
-export interface ObjType extends BaseFlowType {
-  kind: 'Obj';
-  objtype: ObjTypeObj;
-}
-
-export interface ArrType extends BaseFlowType {
-  kind: 'Arr';
-  arrtype: ArrTypeObj;
-}
-
-export interface ClassType extends BaseFlowType {
-  kind: 'Class';
-  type: FlowType;
-}
-
-export interface InstanceType extends BaseFlowType {
-  kind: 'Instance';
-  instance: InstanceT;
-}
-
-export interface SingletonStrType extends BaseFlowType {
-  kind: 'SingletonStr';
-  from_annot: boolean;
-  value: string;
-}
-
-export interface NumericStrKeyType extends BaseFlowType {
-  kind: 'NumericStrKey';
-  number: string;
-  string: string;
-}
-
-export interface SingletonNumType extends BaseFlowType {
-  kind: 'SingletonNum';
-  from_annot: boolean;
-  number: string;
-  string: string;
-}
-
-export interface SingletonBoolType extends BaseFlowType {
-  kind: 'SingletonBool';
-  from_annot: boolean;
-  value: boolean;
-}
-
-export interface SingletonBigIntType extends BaseFlowType {
-  kind: 'SingletonBigInt';
-  from_annot: boolean;
-  value: string;
-}
-
-export interface TypeType extends BaseFlowType {
-  kind: 'Type';
-  type_kind: TypeTKind;
-  type: FlowType;
-}
-
-export type TypeTKind =
-  | 'TypeAliasKind'
-  | 'TypeParamKind'
-  | 'OpaqueKind'
-  | 'ImportTypeofKind'
-  | 'ImportClassKind'
-  | 'ImportEnumKind'
-  | 'InstanceKind'
-  | 'RenderTypeKind';
-
-export interface PolyType extends BaseFlowType {
-  kind: 'Poly';
-  tparams: Array<TypeParam>;
-  t_out: FlowType;
-  id: string;
-}
-
-export interface ReactAbstractComponentType extends BaseFlowType {
-  kind: 'ReactAbstractComponent';
-  config: FlowType;
-  renders: FlowType;
-  instance: ComponentInstance;
-  component_kind: ComponentKind;
-}
-
-export type ComponentInstance =
-  | {kind: 'RefSetterProp'; type: FlowType}
-  | {kind: 'Omitted'};
-
-export type ComponentKind =
-  | {kind: 'Structural'}
-  | {kind: 'Nominal'; id: string; name: string; types: Array<FlowType> | null};
-
-export interface RendersType extends BaseFlowType {
-  kind: 'Renders';
-  form: CanonicalRendersForm;
-}
-
-export interface EnumValueType extends BaseFlowType {
-  kind: 'EnumValue';
-  enum_info: EnumInfo;
-}
-
-export interface EnumObjectType extends BaseFlowType {
-  kind: 'EnumObject';
-  enum_value_t: FlowType;
-  enum_info: EnumInfo;
-}
-
-// ObjKind types
-export type ObjKind =
-  | {kind: 'Exact'}
-  | {kind: 'Inexact'}
-  | {kind: 'Indexed'; dicttype: DictType};
-
-// DictType definition
-export interface DictType {
-  dict_name: string | null;
-  key: FlowType;
-  value: FlowType;
-  dict_polarity: Polarity;
-}
-
-// ArrType types
-export type ArrTypeObj = ArrayAT | TupleAT | ROArrayAT;
-
-export interface ArrayAT {
-  kind: 'ArrayAT';
-  elem_t: FlowType;
-}
-
-export interface TupleAT {
-  kind: 'TupleAT';
-  elem_t: FlowType;
-  elements: Array<TupleElement>;
-  min_arity: number;
-  max_arity: number;
-  inexact: boolean;
-}
-
-export interface ROArrayAT {
-  kind: 'ROArrayAT';
-  elem_t: FlowType;
-}
-
-// TupleElement definition
-export interface TupleElement {
-  name: string | null;
-  t: FlowType;
-  polarity: Polarity;
-  optional: boolean;
-}
-
-// Flags definition
-export interface Flags {
-  obj_kind: ObjKind;
-}
-
-// Property types
-export type Property =
-  | FieldProperty
-  | GetProperty
-  | SetProperty
-  | GetSetProperty
-  | MethodProperty;
-
-export interface FieldProperty {
-  kind: 'Field';
-  type: FlowType;
-  polarity: Polarity;
-}
-
-export interface GetProperty {
-  kind: 'Get';
-  type: FlowType;
-}
-
-export interface SetProperty {
-  kind: 'Set';
-  type: FlowType;
-}
-
-export interface GetSetProperty {
-  kind: 'GetSet';
-  get_type: FlowType;
-  set_type: FlowType;
-}
-
-export interface MethodProperty {
-  kind: 'Method';
-  type: FlowType;
-}
-
-// PropertyMap definition
-export interface PropertyMap {
-  [key: string]: Property; // For other properties in the map
-}
-
-// ObjType definition
-export interface ObjTypeObj {
-  flags: Flags;
-  props: PropertyMap;
-  proto_t: FlowType;
-  call_t: number | null;
-}
-
-// FunType definition
-export interface FunTypeObj {
-  this_t: {
-    type: FlowType;
-    status: ThisStatus;
-  };
-  params: Array<{
-    name: string | null;
-    type: FlowType;
-  }>;
-  rest_param: null | {
-    name: string | null;
-    type: FlowType;
-  };
-  return_t: FlowType;
-  type_guard: null | {
-    inferred: boolean;
-    param_name: string;
-    type_guard: FlowType;
-    one_sided: boolean;
-  };
-  effect: Effect;
-}
-
-// ThisStatus types
-export type ThisStatus =
-  | {kind: 'This_Method'; unbound: boolean}
-  | {kind: 'This_Function'};
-
-// Effect types
-export type Effect =
-  | {kind: 'HookDecl'; id: string}
-  | {kind: 'HookAnnot'}
-  | {kind: 'ArbitraryEffect'}
-  | {kind: 'AnyEffect'};
-
-// Destructor types
-export type Destructor =
-  | NonMaybeTypeDestructor
-  | PropertyTypeDestructor
-  | ElementTypeDestructor
-  | OptionalIndexedAccessNonMaybeTypeDestructor
-  | OptionalIndexedAccessResultTypeDestructor
-  | ExactTypeDestructor
-  | ReadOnlyTypeDestructor
-  | PartialTypeDestructor
-  | RequiredTypeDestructor
-  | SpreadTypeDestructor
-  | SpreadTupleTypeDestructor
-  | RestTypeDestructor
-  | ValuesTypeDestructor
-  | ConditionalTypeDestructor
-  | TypeMapDestructor
-  | ReactElementPropsTypeDestructor
-  | ReactElementConfigTypeDestructor
-  | ReactCheckComponentConfigDestructor
-  | ReactDRODestructor
-  | MakeHooklikeDestructor
-  | MappedTypeDestructor
-  | EnumTypeDestructor;
-
-export interface NonMaybeTypeDestructor {
-  kind: 'NonMaybeType';
-}
-
-export interface PropertyTypeDestructor {
-  kind: 'PropertyType';
-  name: string;
-}
-
-export interface ElementTypeDestructor {
-  kind: 'ElementType';
-  index_type: FlowType;
-}
-
-export interface OptionalIndexedAccessNonMaybeTypeDestructor {
-  kind: 'OptionalIndexedAccessNonMaybeType';
-  index: OptionalIndexedAccessIndex;
-}
-
-export type OptionalIndexedAccessIndex =
-  | {kind: 'StrLitIndex'; name: string}
-  | {kind: 'TypeIndex'; type: FlowType};
-
-export interface OptionalIndexedAccessResultTypeDestructor {
-  kind: 'OptionalIndexedAccessResultType';
-}
-
-export interface ExactTypeDestructor {
-  kind: 'ExactType';
-}
-
-export interface ReadOnlyTypeDestructor {
-  kind: 'ReadOnlyType';
-}
-
-export interface PartialTypeDestructor {
-  kind: 'PartialType';
-}
-
-export interface RequiredTypeDestructor {
-  kind: 'RequiredType';
-}
-
-export interface SpreadTypeDestructor {
-  kind: 'SpreadType';
-  target: SpreadTarget;
-  operands: Array<SpreadOperand>;
-  operand_slice: Slice | null;
-}
-
-export type SpreadTarget =
-  | {kind: 'Value'; make_seal: 'Sealed' | 'Frozen' | 'As_Const'}
-  | {kind: 'Annot'; make_exact: boolean};
-
-export type SpreadOperand = {kind: 'Type'; type: FlowType} | Slice;
-
-export interface Slice {
-  kind: 'Slice';
-  prop_map: PropertyMap;
-  generics: Array<string>;
-  dict: DictType | null;
-  reachable_targs: Array<{
-    type: FlowType;
-    polarity: Polarity;
-  }>;
-}
-
-export interface SpreadTupleTypeDestructor {
-  kind: 'SpreadTupleType';
-  inexact: boolean;
-  resolved_rev: string;
-  unresolved: string;
-}
-
-export interface RestTypeDestructor {
-  kind: 'RestType';
-  merge_mode: RestMergeMode;
-  type: FlowType;
-}
-
-export type RestMergeMode =
-  | {kind: 'SpreadReversal'}
-  | {kind: 'ReactConfigMerge'; polarity: Polarity}
-  | {kind: 'Omit'};
-
-export interface ValuesTypeDestructor {
-  kind: 'ValuesType';
-}
-
-export interface ConditionalTypeDestructor {
-  kind: 'ConditionalType';
-  distributive_tparam_name: string | null;
-  infer_tparams: string;
-  extends_t: FlowType;
-  true_t: FlowType;
-  false_t: FlowType;
-}
-
-export interface TypeMapDestructor {
-  kind: 'ObjectKeyMirror';
-}
-
-export interface ReactElementPropsTypeDestructor {
-  kind: 'ReactElementPropsType';
-}
-
-export interface ReactElementConfigTypeDestructor {
-  kind: 'ReactElementConfigType';
-}
-
-export interface ReactCheckComponentConfigDestructor {
-  kind: 'ReactCheckComponentConfig';
-  props: {
-    [key: string]: Property;
-  };
-}
-
-export interface ReactDRODestructor {
-  kind: 'ReactDRO';
-  dro_type:
-    | 'HookReturn'
-    | 'HookArg'
-    | 'Props'
-    | 'ImmutableAnnot'
-    | 'DebugAnnot';
-}
-
-export interface MakeHooklikeDestructor {
-  kind: 'MakeHooklike';
-}
-
-export interface MappedTypeDestructor {
-  kind: 'MappedType';
-  homomorphic: Homomorphic;
-  distributive_tparam_name: string | null;
-  property_type: FlowType;
-  mapped_type_flags: {
-    variance: Polarity;
-    optional: 'MakeOptional' | 'RemoveOptional' | 'KeepOptionality';
-  };
-}
-
-export type Homomorphic =
-  | {kind: 'Homomorphic'}
-  | {kind: 'Unspecialized'}
-  | {kind: 'SemiHomomorphic'; type: FlowType};
-
-export interface EnumTypeDestructor {
-  kind: 'EnumType';
-}
-
-// Union of all possible Flow types
-export type FlowType =
-  | OpenType
-  | DefType
-  | EvalType
-  | GenericType
-  | ThisInstanceType
-  | ThisTypeAppType
-  | TypeAppType
-  | FunProtoType
-  | ObjProtoType
-  | NullProtoType
-  | FunProtoBindType
-  | IntersectionType
-  | UnionType
-  | MaybeType
-  | OptionalType
-  | KeysType
-  | AnnotType
-  | OpaqueType
-  | NamespaceType
-  | AnyType
-  | StrUtilType;

compiler/packages/babel-plugin-react-compiler/src/Flood/TypeErrors.ts

@@ -1,131 +0,0 @@
-import {CompilerError, SourceLocation} from '..';
-import {
-  ConcreteType,
-  printConcrete,
-  printType,
-  StructuralValue,
-  Type,
-  VariableId,
-} from './Types';
-
-export function unsupportedLanguageFeature(
-  desc: string,
-  loc: SourceLocation,
-): never {
-  CompilerError.throwInvalidJS({
-    reason: `Typedchecker does not currently support language feature: ${desc}`,
-    loc,
-  });
-}
-
-export type UnificationError =
-  | {
-      kind: 'TypeUnification';
-      left: ConcreteType<Type>;
-      right: ConcreteType<Type>;
-    }
-  | {
-      kind: 'StructuralUnification';
-      left: StructuralValue;
-      right: ConcreteType<Type>;
-    };
-
-function printUnificationError(err: UnificationError): string {
-  if (err.kind === 'TypeUnification') {
-    return `${printConcrete(err.left, printType)} is incompatible with ${printConcrete(err.right, printType)}`;
-  } else {
-    return `structural ${err.left.kind} is incompatible with ${printConcrete(err.right, printType)}`;
-  }
-}
-
-export function raiseUnificationErrors(
-  errs: null | Array<UnificationError>,
-  loc: SourceLocation,
-): void {
-  if (errs != null) {
-    if (errs.length === 0) {
-      CompilerError.invariant(false, {
-        reason: 'Should not have array of zero errors',
-        loc,
-      });
-    } else if (errs.length === 1) {
-      CompilerError.throwInvalidJS({
-        reason: `Unable to unify types because ${printUnificationError(errs[0])}`,
-        loc,
-      });
-    } else {
-      const messages = errs
-        .map(err => `\t* ${printUnificationError(err)}`)
-        .join('\n');
-      CompilerError.throwInvalidJS({
-        reason: `Unable to unify types because:\n${messages}`,
-        loc,
-      });
-    }
-  }
-}
-
-export function unresolvableTypeVariable(
-  id: VariableId,
-  loc: SourceLocation,
-): never {
-  CompilerError.throwInvalidJS({
-    reason: `Unable to resolve free variable ${id} to a concrete type`,
-    loc,
-  });
-}
-
-export function cannotAddVoid(explicit: boolean, loc: SourceLocation): never {
-  if (explicit) {
-    CompilerError.throwInvalidJS({
-      reason: `Undefined is not a valid operand of \`+\``,
-      loc,
-    });
-  } else {
-    CompilerError.throwInvalidJS({
-      reason: `Value may be undefined, which is not a valid operand of \`+\``,
-      loc,
-    });
-  }
-}
-
-export function unsupportedTypeAnnotation(
-  desc: string,
-  loc: SourceLocation,
-): never {
-  CompilerError.throwInvalidJS({
-    reason: `Typedchecker does not currently support type annotation: ${desc}`,
-    loc,
-  });
-}
-
-export function checkTypeArgumentArity(
-  desc: string,
-  expected: number,
-  actual: number,
-  loc: SourceLocation,
-): void {
-  if (expected !== actual) {
-    CompilerError.throwInvalidJS({
-      reason: `Expected ${desc} to have ${expected} type parameters, got ${actual}`,
-      loc,
-    });
-  }
-}
-
-export function notAFunction(desc: string, loc: SourceLocation): void {
-  CompilerError.throwInvalidJS({
-    reason: `Cannot call ${desc} because it is not a function`,
-    loc,
-  });
-}
-
-export function notAPolymorphicFunction(
-  desc: string,
-  loc: SourceLocation,
-): void {
-  CompilerError.throwInvalidJS({
-    reason: `Cannot call ${desc} with type arguments because it is not a polymorphic function`,
-    loc,
-  });
-}

compiler/packages/babel-plugin-react-compiler/src/Flood/TypeUtils.ts

@@ -1,312 +0,0 @@
-import {GeneratedSource} from '../HIR';
-import {assertExhaustive} from '../Utils/utils';
-import {unsupportedLanguageFeature} from './TypeErrors';
-import {
-  ConcreteType,
-  ResolvedType,
-  TypeParameter,
-  TypeParameterId,
-  DEBUG,
-  printConcrete,
-  printType,
-} from './Types';
-
-export function substitute(
-  type: ConcreteType<ResolvedType>,
-  typeParameters: Array<TypeParameter<ResolvedType>>,
-  typeArguments: Array<ResolvedType>,
-): ResolvedType {
-  const substMap = new Map<TypeParameterId, ResolvedType>();
-  for (let i = 0; i < typeParameters.length; i++) {
-    // TODO: Length checks to make sure type params match up with args
-    const typeParameter = typeParameters[i];
-    const typeArgument = typeArguments[i];
-    substMap.set(typeParameter.id, typeArgument);
-  }
-  const substitutionFunction = (t: ResolvedType): ResolvedType => {
-    // TODO: We really want a stateful mapper or visitor here so that we can model nested polymorphic types
-    if (t.type.kind === 'Generic' && substMap.has(t.type.id)) {
-      const substitutedType = substMap.get(t.type.id)!;
-      return substitutedType;
-    }
-
-    return {
-      kind: 'Concrete',
-      type: mapType(substitutionFunction, t.type),
-      platform: t.platform,
-    };
-  };
-
-  const substituted = mapType(substitutionFunction, type);
-
-  if (DEBUG) {
-    let substs = '';
-    for (let i = 0; i < typeParameters.length; i++) {
-      const typeParameter = typeParameters[i];
-      const typeArgument = typeArguments[i];
-      substs += `[${typeParameter.name}${typeParameter.id} := ${printType(typeArgument)}]`;
-    }
-    console.log(
-      `${printConcrete(type, printType)}${substs} = ${printConcrete(substituted, printType)}`,
-    );
-  }
-
-  return {kind: 'Concrete', type: substituted, platform: /* TODO */ 'shared'};
-}
-
-export function mapType<T, U>(
-  f: (t: T) => U,
-  type: ConcreteType<T>,
-): ConcreteType<U> {
-  switch (type.kind) {
-    case 'Mixed':
-    case 'Number':
-    case 'String':
-    case 'Boolean':
-    case 'Void':
-      return type;
-
-    case 'Nullable':
-      return {
-        kind: 'Nullable',
-        type: f(type.type),
-      };
-
-    case 'Array':
-      return {
-        kind: 'Array',
-        element: f(type.element),
-      };
-
-    case 'Set':
-      return {
-        kind: 'Set',
-        element: f(type.element),
-      };
-
-    case 'Map':
-      return {
-        kind: 'Map',
-        key: f(type.key),
-        value: f(type.value),
-      };
-
-    case 'Function':
-      return {
-        kind: 'Function',
-        typeParameters:
-          type.typeParameters?.map(param => ({
-            id: param.id,
-            name: param.name,
-            bound: f(param.bound),
-          })) ?? null,
-        params: type.params.map(f),
-        returnType: f(type.returnType),
-      };
-
-    case 'Component': {
-      return {
-        kind: 'Component',
-        children: type.children != null ? f(type.children) : null,
-        props: new Map([...type.props.entries()].map(([k, v]) => [k, f(v)])),
-      };
-    }
-
-    case 'Generic':
-      return {
-        kind: 'Generic',
-        id: type.id,
-        bound: f(type.bound),
-      };
-
-    case 'Object':
-      return type;
-
-    case 'Tuple':
-      return {
-        kind: 'Tuple',
-        id: type.id,
-        members: type.members.map(f),
-      };
-
-    case 'Structural':
-      return type;
-
-    case 'Enum':
-    case 'Union':
-    case 'Instance':
-      unsupportedLanguageFeature(type.kind, GeneratedSource);
-
-    default:
-      assertExhaustive(type, 'Unknown type kind');
-  }
-}
-
-export function diff<R, T>(
-  a: ConcreteType<T>,
-  b: ConcreteType<T>,
-  onChild: (a: T, b: T) => R,
-  onChildMismatch: (child: R, cur: R) => R,
-  onMismatch: (a: ConcreteType<T>, b: ConcreteType<T>, cur: R) => R,
-  init: R,
-): R {
-  let errors = init;
-
-  // Check if kinds match
-  if (a.kind !== b.kind) {
-    errors = onMismatch(a, b, errors);
-    return errors;
-  }
-
-  // Based on kind, check other properties
-  switch (a.kind) {
-    case 'Mixed':
-    case 'Number':
-    case 'String':
-    case 'Boolean':
-    case 'Void':
-      // Simple types, no further checks needed
-      break;
-
-    case 'Nullable':
-      // Check the nested type
-      errors = onChildMismatch(onChild(a.type, (b as typeof a).type), errors);
-      break;
-
-    case 'Array':
-    case 'Set':
-      // Check the element type
-      errors = onChildMismatch(
-        onChild(a.element, (b as typeof a).element),
-        errors,
-      );
-      break;
-
-    case 'Map':
-      // Check both key and value types
-      errors = onChildMismatch(onChild(a.key, (b as typeof a).key), errors);
-      errors = onChildMismatch(onChild(a.value, (b as typeof a).value), errors);
-      break;
-
-    case 'Function': {
-      const bFunc = b as typeof a;
-
-      // Check type parameters
-      if ((a.typeParameters == null) !== (bFunc.typeParameters == null)) {
-        errors = onMismatch(a, b, errors);
-      }
-
-      if (a.typeParameters != null && bFunc.typeParameters != null) {
-        if (a.typeParameters.length !== bFunc.typeParameters.length) {
-          errors = onMismatch(a, b, errors);
-        }
-
-        // Type parameters are just numbers, so we can compare them directly
-        for (let i = 0; i < a.typeParameters.length; i++) {
-          if (a.typeParameters[i] !== bFunc.typeParameters[i]) {
-            errors = onMismatch(a, b, errors);
-          }
-        }
-      }
-
-      // Check parameters
-      if (a.params.length !== bFunc.params.length) {
-        errors = onMismatch(a, b, errors);
-      }
-
-      for (let i = 0; i < a.params.length; i++) {
-        errors = onChildMismatch(onChild(a.params[i], bFunc.params[i]), errors);
-      }
-
-      // Check return type
-      errors = onChildMismatch(onChild(a.returnType, bFunc.returnType), errors);
-      break;
-    }
-
-    case 'Component': {
-      const bComp = b as typeof a;
-
-      // Check children
-      if (a.children !== bComp.children) {
-        errors = onMismatch(a, b, errors);
-      }
-
-      // Check props
-      if (a.props.size !== bComp.props.size) {
-        errors = onMismatch(a, b, errors);
-      }
-
-      for (const [k, v] of a.props) {
-        const bProp = bComp.props.get(k);
-        if (bProp == null) {
-          errors = onMismatch(a, b, errors);
-        } else {
-          errors = onChildMismatch(onChild(v, bProp), errors);
-        }
-      }
-
-      break;
-    }
-
-    case 'Generic': {
-      // Check that the type parameter IDs match
-      if (a.id !== (b as typeof a).id) {
-        errors = onMismatch(a, b, errors);
-      }
-      break;
-    }
-    case 'Structural': {
-      const bStruct = b as typeof a;
-
-      // Check that the structural IDs match
-      if (a.id !== bStruct.id) {
-        errors = onMismatch(a, b, errors);
-      }
-      break;
-    }
-    case 'Object': {
-      const bNom = b as typeof a;
-
-      // Check that the nominal IDs match
-      if (a.id !== bNom.id) {
-        errors = onMismatch(a, b, errors);
-      }
-      break;
-    }
-
-    case 'Tuple': {
-      const bTuple = b as typeof a;
-
-      // Check that the tuple IDs match
-      if (a.id !== bTuple.id) {
-        errors = onMismatch(a, b, errors);
-      }
-      for (let i = 0; i < a.members.length; i++) {
-        errors = onChildMismatch(
-          onChild(a.members[i], bTuple.members[i]),
-          errors,
-        );
-      }
-
-      break;
-    }
-
-    case 'Enum':
-    case 'Instance':
-    case 'Union': {
-      unsupportedLanguageFeature(a.kind, GeneratedSource);
-    }
-
-    default:
-      assertExhaustive(a, 'Unknown type kind');
-  }
-
-  return errors;
-}
-
-export function filterOptional(t: ResolvedType): ResolvedType {
-  if (t.kind === 'Concrete' && t.type.kind === 'Nullable') {
-    return t.type.type;
-  }
-  return t;
-}

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

@@ -189,7 +189,6 @@ export function lower(
     const fallthrough = builder.reserve('block');
     const terminal: ReturnTerminal = {
       kind: 'return',
-      returnVariant: 'Implicit',
       loc: GeneratedSource,
       value: lowerExpressionToTemporary(builder, body),
       id: makeInstructionId(0),
@@ -220,7 +219,6 @@ export function lower(
   builder.terminate(
     {
       kind: 'return',
-      returnVariant: 'Void',
       loc: GeneratedSource,
       value: lowerValueToTemporary(builder, {
         kind: 'Primitive',
@@ -304,7 +302,6 @@ function lowerStatement(
       }
       const terminal: ReturnTerminal = {
         kind: 'return',
-        returnVariant: 'Explicit',
         loc: stmt.node.loc ?? GeneratedSource,
         value,
         id: makeInstructionId(0),

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

@@ -49,7 +49,6 @@ import {
 } from './ObjectShape';
 import {Scope as BabelScope, NodePath} from '@babel/traverse';
 import {TypeSchema} from './TypeSchema';
-import {FlowTypeEnv} from '../Flood/Types';
 
 export const ReactElementSymbolSchema = z.object({
   elementSymbol: z.union([
@@ -244,12 +243,6 @@ export const EnvironmentConfigSchema = z.object({
    */
   enableUseTypeAnnotations: z.boolean().default(false),
 
-  /**
-   * Allows specifying a function that can populate HIR with type information from
-   * Flow
-   */
-  flowTypeProvider: z.nullable(z.function().args(z.string())).default(null),
-
   /**
    * Enable a new model for mutability and aliasing inference
    */
@@ -330,12 +323,6 @@ export const EnvironmentConfigSchema = z.object({
    */
   validateNoSetStateInEffects: z.boolean().default(false),
 
-  /**
-   * Validates that effects are not used to calculate derived data which could instead be computed
-   * during render.
-   */
-  validateNoDerivedComputationsInEffects: z.boolean().default(false),
-
   /**
    * Validates against creating JSX within a try block and recommends using an error boundary
    * instead.
@@ -621,7 +608,7 @@ export const EnvironmentConfigSchema = z.object({
    *
    * Here the variables `ref` and `myRef` will be typed as Refs.
    */
-  enableTreatRefLikeIdentifiersAsRefs: z.boolean().default(true),
+  enableTreatRefLikeIdentifiersAsRefs: z.boolean().default(false),
 
   /*
    * If specified a value, the compiler lowers any calls to `useContext` to use
@@ -644,17 +631,6 @@ export const EnvironmentConfigSchema = z.object({
    * ```
    */
   lowerContextAccess: ExternalFunctionSchema.nullable().default(null),
-
-  /**
-   * If enabled, will validate useMemos that don't return any values:
-   *
-   * Valid:
-   *   useMemo(() => foo, [foo]);
-   *   useMemo(() => { return foo }, [foo]);
-   * Invalid:
-   *   useMemo(() => { ... }, [...]);
-   */
-  validateNoVoidUseMemo: z.boolean().default(false),
 });
 
 export type EnvironmentConfig = z.infer<typeof EnvironmentConfigSchema>;
@@ -704,8 +680,6 @@ export class Environment {
   #hoistedIdentifiers: Set<t.Identifier>;
   parentFunction: NodePath<t.Function>;
 
-  #flowTypeEnvironment: FlowTypeEnv | null;
-
   constructor(
     scope: BabelScope,
     fnType: ReactFunctionType,
@@ -774,26 +748,6 @@ export class Environment {
     this.parentFunction = parentFunction;
     this.#contextIdentifiers = contextIdentifiers;
     this.#hoistedIdentifiers = new Set();
-
-    if (config.flowTypeProvider != null) {
-      this.#flowTypeEnvironment = new FlowTypeEnv();
-      CompilerError.invariant(code != null, {
-        reason:
-          'Expected Environment to be initialized with source code when a Flow type provider is specified',
-        loc: null,
-      });
-      this.#flowTypeEnvironment.init(this, code);
-    } else {
-      this.#flowTypeEnvironment = null;
-    }
-  }
-
-  get typeContext(): FlowTypeEnv {
-    CompilerError.invariant(this.#flowTypeEnvironment != null, {
-      reason: 'Flow type environment not initialized',
-      loc: null,
-    });
-    return this.#flowTypeEnvironment;
   }
 
   get isInferredMemoEnabled(): boolean {

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

@@ -114,99 +114,6 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
           returnValueKind: ValueKind.Mutable,
         }),
       ],
-      [
-        'entries',
-        addFunction(DEFAULT_SHAPES, [], {
-          positionalParams: [Effect.Capture],
-          restParam: null,
-          returnType: {kind: 'Object', shapeId: BuiltInArrayId},
-          calleeEffect: Effect.Read,
-          returnValueKind: ValueKind.Mutable,
-          aliasing: {
-            receiver: '@receiver',
-            params: ['@object'],
-            rest: null,
-            returns: '@returns',
-            temporaries: [],
-            effects: [
-              {
-                kind: 'Create',
-                into: '@returns',
-                reason: ValueReason.KnownReturnSignature,
-                value: ValueKind.Mutable,
-              },
-              // Object values are captured into the return
-              {
-                kind: 'Capture',
-                from: '@object',
-                into: '@returns',
-              },
-            ],
-          },
-        }),
-      ],
-      [
-        'keys',
-        addFunction(DEFAULT_SHAPES, [], {
-          positionalParams: [Effect.Read],
-          restParam: null,
-          returnType: {kind: 'Object', shapeId: BuiltInArrayId},
-          calleeEffect: Effect.Read,
-          returnValueKind: ValueKind.Mutable,
-          aliasing: {
-            receiver: '@receiver',
-            params: ['@object'],
-            rest: null,
-            returns: '@returns',
-            temporaries: [],
-            effects: [
-              {
-                kind: 'Create',
-                into: '@returns',
-                reason: ValueReason.KnownReturnSignature,
-                value: ValueKind.Mutable,
-              },
-              // Only keys are captured, and keys are immutable
-              {
-                kind: 'ImmutableCapture',
-                from: '@object',
-                into: '@returns',
-              },
-            ],
-          },
-        }),
-      ],
-      [
-        'values',
-        addFunction(DEFAULT_SHAPES, [], {
-          positionalParams: [Effect.Capture],
-          restParam: null,
-          returnType: {kind: 'Object', shapeId: BuiltInArrayId},
-          calleeEffect: Effect.Read,
-          returnValueKind: ValueKind.Mutable,
-          aliasing: {
-            receiver: '@receiver',
-            params: ['@object'],
-            rest: null,
-            returns: '@returns',
-            temporaries: [],
-            effects: [
-              {
-                kind: 'Create',
-                into: '@returns',
-                reason: ValueReason.KnownReturnSignature,
-                value: ValueKind.Mutable,
-              },
-              // Object values are captured into the return
-              {
-                kind: 'Capture',
-                from: '@object',
-                into: '@returns',
-              },
-            ],
-          },
-        }),
-      ],
     ]),
   ],
   [

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

@@ -14,7 +14,6 @@ import type {HookKind} from './ObjectShape';
 import {Type, makeType} from './Types';
 import {z} from 'zod';
 import type {AliasingEffect} from '../Inference/AliasingEffects';
-import {isReservedWord} from '../Utils/Keyword';
 
 /*
  * *******************************************************************************************
@@ -447,20 +446,8 @@ export type ThrowTerminal = {
 };
 export type Case = {test: Place | null; block: BlockId};
 
-export type ReturnVariant = 'Void' | 'Implicit' | 'Explicit';
 export type ReturnTerminal = {
   kind: 'return';
-  /**
-   * Void:
-   *   () => { ... }
-   *   function() { ... }
-   * Implicit (ArrowFunctionExpression only):
-   *   () => foo
-   * Explicit:
-   *   () => { return ... }
-   *   function () { return ... }
-   */
-  returnVariant: ReturnVariant;
   loc: SourceLocation;
   value: Place;
   id: InstructionId;
@@ -1321,21 +1308,12 @@ export function forkTemporaryIdentifier(
  * original source code.
  */
 export function makeIdentifierName(name: string): ValidatedIdentifier {
-  if (isReservedWord(name)) {
-    CompilerError.throwInvalidJS({
-      reason: 'Expected a non-reserved identifier name',
-      loc: GeneratedSource,
-      description: `\`${name}\` is a reserved word in JavaScript and cannot be used as an identifier name`,
-      suggestions: null,
-    });
-  } else {
-    CompilerError.invariant(t.isValidIdentifier(name), {
-      reason: `Expected a valid identifier name`,
-      loc: GeneratedSource,
-      description: `\`${name}\` is not a valid JavaScript identifier`,
-      suggestions: null,
-    });
-  }
+  CompilerError.invariant(t.isValidIdentifier(name), {
+    reason: `Expected a valid identifier name`,
+    loc: GeneratedSource,
+    description: `\`${name}\` is not a valid JavaScript identifier`,
+    suggestions: null,
+  });
   return {
     kind: 'named',
     value: name as ValidIdentifierName,

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

@@ -142,7 +142,6 @@ function parseAliasingSignatureConfig(
   const effects = typeConfig.effects.map(
     (effect: AliasingEffectConfig): AliasingEffect => {
       switch (effect.kind) {
-        case 'ImmutableCapture':
         case 'CreateFrom':
         case 'Capture':
         case 'Alias':
@@ -1212,8 +1211,6 @@ addObject(BUILTIN_SHAPES, BuiltInRefValueId, [
   ['*', {kind: 'Object', shapeId: BuiltInRefValueId}],
 ]);
 
-addObject(BUILTIN_SHAPES, ReanimatedSharedValueId, []);
-
 addFunction(
   BUILTIN_SHAPES,
   [],

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

@@ -215,7 +215,7 @@ export function printTerminal(terminal: Terminal): Array<string> | string {
       break;
     }
     case 'return': {
-      value = `[${terminal.id}] Return ${terminal.returnVariant}${
+      value = `[${terminal.id}] Return${
         terminal.value != null ? ' ' + printPlace(terminal.value) : ''
       }`;
       if (terminal.effects != null) {

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

@@ -111,19 +111,6 @@ export const AliasEffectSchema: z.ZodType<AliasEffectConfig> = z.object({
   into: LifetimeIdSchema,
 });
 
-export type ImmutableCaptureEffectConfig = {
-  kind: 'ImmutableCapture';
-  from: string;
-  into: string;
-};
-
-export const ImmutableCaptureEffectSchema: z.ZodType<ImmutableCaptureEffectConfig> =
-  z.object({
-    kind: z.literal('ImmutableCapture'),
-    from: LifetimeIdSchema,
-    into: LifetimeIdSchema,
-  });
-
 export type CaptureEffectConfig = {
   kind: 'Capture';
   from: string;
@@ -200,7 +187,6 @@ export type AliasingEffectConfig =
   | AssignEffectConfig
   | AliasEffectConfig
   | CaptureEffectConfig
-  | ImmutableCaptureEffectConfig
   | ImpureEffectConfig
   | MutateEffectConfig
   | MutateTransitiveConditionallyConfig
@@ -213,7 +199,6 @@ export const AliasingEffectSchema: z.ZodType<AliasingEffectConfig> = z.union([
   AssignEffectSchema,
   AliasEffectSchema,
   CaptureEffectSchema,
-  ImmutableCaptureEffectSchema,
   ImpureEffectSchema,
   MutateEffectSchema,
   MutateTransitiveConditionallySchema,

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

@@ -777,7 +777,6 @@ export function mapTerminalSuccessors(
     case 'return': {
       return {
         kind: 'return',
-        returnVariant: terminal.returnVariant,
         loc: terminal.loc,
         value: terminal.value,
         id: makeInstructionId(0),

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

@@ -50,7 +50,7 @@ export type AliasingEffect =
   /**
    * Mutate the value and any direct aliases (not captures). Errors if the value is not mutable.
    */
-  | {kind: 'Mutate'; value: Place; reason?: MutationReason | null}
+  | {kind: 'Mutate'; value: Place}
   /**
    * Mutate the value and any direct aliases (not captures), but only if the value is known mutable.
    * This should be rare.
@@ -174,8 +174,6 @@ export type AliasingEffect =
       place: Place;
     };
 
-export type MutationReason = {kind: 'AssignCurrentProperty'};
-
 export function hashEffect(effect: AliasingEffect): string {
   switch (effect.kind) {
     case 'Apply': {

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

@@ -5,12 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {
-  CompilerDiagnostic,
-  CompilerError,
-  ErrorSeverity,
-  SourceLocation,
-} from '..';
+import {CompilerError, SourceLocation} from '..';
 import {
   CallExpression,
   Effect,
@@ -35,7 +30,6 @@ import {
   makeInstructionId,
 } from '../HIR';
 import {createTemporaryPlace, markInstructionIds} from '../HIR/HIRBuilder';
-import {Result} from '../Utils/Result';
 
 type ManualMemoCallee = {
   kind: 'useMemo' | 'useCallback';
@@ -289,43 +283,26 @@ function extractManualMemoizationArgs(
   instr: TInstruction<CallExpression> | TInstruction<MethodCall>,
   kind: 'useCallback' | 'useMemo',
   sidemap: IdentifierSidemap,
-  errors: CompilerError,
 ): {
-  fnPlace: Place | null;
+  fnPlace: Place;
   depsList: Array<ManualMemoDependency> | null;
 } {
   const [fnPlace, depsListPlace] = instr.value.args as Array<
     Place | SpreadPattern | undefined
   >;
   if (fnPlace == null) {
-    errors.pushDiagnostic(
-      CompilerDiagnostic.create({
-        severity: ErrorSeverity.InvalidReact,
-        category: `Expected a callback function to be passed to ${kind}`,
-        description: `Expected a callback function to be passed to ${kind}`,
-        suggestions: null,
-      }).withDetail({
-        kind: 'error',
-        loc: instr.value.loc,
-        message: `Expected a callback function to be passed to ${kind}`,
-      }),
-    );
-    return {fnPlace: null, depsList: null};
+    CompilerError.throwInvalidReact({
+      reason: `Expected a callback function to be passed to ${kind}`,
+      loc: instr.value.loc,
+      suggestions: null,
+    });
   }
   if (fnPlace.kind === 'Spread' || depsListPlace?.kind === 'Spread') {
-    errors.pushDiagnostic(
-      CompilerDiagnostic.create({
-        severity: ErrorSeverity.InvalidReact,
-        category: `Unexpected spread argument to ${kind}`,
-        description: `Unexpected spread argument to ${kind}`,
-        suggestions: null,
-      }).withDetail({
-        kind: 'error',
-        loc: instr.value.loc,
-        message: `Unexpected spread argument to ${kind}`,
-      }),
-    );
-    return {fnPlace: null, depsList: null};
+    CompilerError.throwInvalidReact({
+      reason: `Unexpected spread argument to ${kind}`,
+      loc: instr.value.loc,
+      suggestions: null,
+    });
   }
   let depsList: Array<ManualMemoDependency> | null = null;
   if (depsListPlace != null) {
@@ -333,40 +310,23 @@ function extractManualMemoizationArgs(
       depsListPlace.identifier.id,
     );
     if (maybeDepsList == null) {
-      errors.pushDiagnostic(
-        CompilerDiagnostic.create({
-          severity: ErrorSeverity.InvalidReact,
-          category: `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,
-        }).withDetail({
-          kind: 'error',
-          loc: depsListPlace.loc,
-          message: `Expected the dependency list for ${kind} to be an array literal`,
-        }),
-      );
-      return {fnPlace, depsList: null};
+      CompilerError.throwInvalidReact({
+        reason: `Expected the dependency list for ${kind} to be an array literal`,
+        suggestions: null,
+        loc: depsListPlace.loc,
+      });
     }
-    depsList = [];
-    for (const dep of maybeDepsList) {
+    depsList = maybeDepsList.map(dep => {
       const maybeDep = sidemap.maybeDeps.get(dep.identifier.id);
       if (maybeDep == null) {
-        errors.pushDiagnostic(
-          CompilerDiagnostic.create({
-            severity: ErrorSeverity.InvalidReact,
-            category: `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,
-          }).withDetail({
-            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);
+        CompilerError.throwInvalidReact({
+          reason: `Expected the dependency list to be an array of simple expressions (e.g. \`x\`, \`x.y.z\`, \`x?.y?.z\`)`,
+          suggestions: null,
+          loc: dep.loc,
+        });
       }
-    }
+      return maybeDep;
+    });
   }
   return {
     fnPlace,
@@ -381,14 +341,8 @@ function extractManualMemoizationArgs(
  * rely on type inference to find useMemo/useCallback invocations, and instead does basic tracking
  * of globals and property loads to find both direct calls as well as usage via the React namespace,
  * eg `React.useMemo()`.
- *
- * This pass also validates that useMemo callbacks return a value (not void), ensuring that useMemo
- * is only used for memoizing values and not for running arbitrary side effects.
  */
-export function dropManualMemoization(
-  func: HIRFunction,
-): Result<void, CompilerError> {
-  const errors = new CompilerError();
+export function dropManualMemoization(func: HIRFunction): void {
   const isValidationEnabled =
     func.env.config.validatePreserveExistingMemoizationGuarantees ||
     func.env.config.validateNoSetStateInRender ||
@@ -435,47 +389,7 @@ export function dropManualMemoization(
             instr as TInstruction<CallExpression> | TInstruction<MethodCall>,
             manualMemo.kind,
             sidemap,
-            errors,
           );
-
-          if (fnPlace == null) {
-            continue;
-          }
-
-          /**
-           * Bailout on void return useMemos. This is an anti-pattern where code might be using
-           * useMemo like useEffect: running arbirtary side-effects synced to changes in specific
-           * values.
-           */
-          if (
-            func.env.config.validateNoVoidUseMemo &&
-            manualMemo.kind === 'useMemo'
-          ) {
-            const funcToCheck = sidemap.functions.get(
-              fnPlace.identifier.id,
-            )?.value;
-            if (funcToCheck !== undefined && funcToCheck.loweredFunc.func) {
-              if (!hasNonVoidReturn(funcToCheck.loweredFunc.func)) {
-                errors.pushDiagnostic(
-                  CompilerDiagnostic.create({
-                    severity: ErrorSeverity.InvalidReact,
-                    category: 'useMemo() callbacks must return a value',
-                    description: `This ${
-                      manualMemo.loadInstr.value.kind === 'PropertyLoad'
-                        ? 'React.useMemo'
-                        : 'useMemo'
-                    } callback doesn't return a value. useMemo is for computing and caching values, not for arbitrary side effects.`,
-                    suggestions: null,
-                  }).withDetail({
-                    kind: 'error',
-                    loc: instr.value.loc,
-                    message: 'useMemo() callbacks must return a value',
-                  }),
-                );
-              }
-            }
-          }
-
           instr.value = getManualMemoizationReplacement(
             fnPlace,
             instr.value.loc,
@@ -496,19 +410,11 @@ export function dropManualMemoization(
              * is rare and likely sketchy.
              */
             if (!sidemap.functions.has(fnPlace.identifier.id)) {
-              errors.pushDiagnostic(
-                CompilerDiagnostic.create({
-                  severity: ErrorSeverity.InvalidReact,
-                  category: `Expected the first argument to be an inline function expression`,
-                  description: `Expected the first argument to be an inline function expression`,
-                  suggestions: [],
-                }).withDetail({
-                  kind: 'error',
-                  loc: fnPlace.loc,
-                  message: `Expected the first argument to be an inline function expression`,
-                }),
-              );
-              continue;
+              CompilerError.throwInvalidReact({
+                reason: `Expected the first argument to be an inline function expression`,
+                suggestions: [],
+                loc: fnPlace.loc,
+              });
             }
             const memoDecl: Place =
               manualMemo.kind === 'useMemo'
@@ -580,8 +486,6 @@ export function dropManualMemoization(
       markInstructionIds(func.body);
     }
   }
-
-  return errors.asResult();
 }
 
 function findOptionalPlaces(fn: HIRFunction): Set<IdentifierId> {
@@ -626,17 +530,3 @@ function findOptionalPlaces(fn: HIRFunction): Set<IdentifierId> {
   }
   return optionals;
 }
-
-function hasNonVoidReturn(func: HIRFunction): boolean {
-  for (const [, block] of func.body.blocks) {
-    if (block.terminal.kind === 'return') {
-      if (
-        block.terminal.returnVariant === 'Explicit' ||
-        block.terminal.returnVariant === 'Implicit'
-      ) {
-        return true;
-      }
-    }
-  }
-  return false;
-}

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

@@ -68,12 +68,7 @@ import {FunctionSignature} from '../HIR/ObjectShape';
 import {getWriteErrorReason} from './InferFunctionEffects';
 import prettyFormat from 'pretty-format';
 import {createTemporaryPlace} from '../HIR/HIRBuilder';
-import {
-  AliasingEffect,
-  AliasingSignature,
-  hashEffect,
-  MutationReason,
-} from './AliasingEffects';
+import {AliasingEffect, AliasingSignature, hashEffect} from './AliasingEffects';
 
 const DEBUG = false;
 
@@ -457,28 +452,18 @@ function applySignature(
               effect.value.identifier.name.kind === 'named'
                 ? `\`${effect.value.identifier.name.value}\``
                 : 'value';
-            const diagnostic = CompilerDiagnostic.create({
-              severity: ErrorSeverity.InvalidReact,
-              category: 'This value cannot be modified',
-              description: `${reason}.`,
-            }).withDetail({
-              kind: 'error',
-              loc: effect.value.loc,
-              message: `${variable} cannot be modified`,
-            });
-            if (
-              effect.kind === 'Mutate' &&
-              effect.reason?.kind === 'AssignCurrentProperty'
-            ) {
-              diagnostic.withDetail({
-                kind: 'hint',
-                message: `Hint: If this value is a Ref (value returned by \`useRef()\`), rename the variable to end in "Ref".`,
-              });
-            }
             effects.push({
               kind: 'MutateFrozen',
               place: effect.value,
-              error: diagnostic,
+              error: CompilerDiagnostic.create({
+                severity: ErrorSeverity.InvalidReact,
+                category: 'This value cannot be modified',
+                description: `${reason}.`,
+              }).withDetail({
+                kind: 'error',
+                loc: effect.value.loc,
+                message: `${variable} cannot be modified`,
+              }),
             });
           }
         }
@@ -1081,24 +1066,6 @@ function applyEffect(
             effect.value.identifier.name.kind === 'named'
               ? `\`${effect.value.identifier.name.value}\``
               : 'value';
-          const diagnostic = CompilerDiagnostic.create({
-            severity: ErrorSeverity.InvalidReact,
-            category: 'This value cannot be modified',
-            description: `${reason}.`,
-          }).withDetail({
-            kind: 'error',
-            loc: effect.value.loc,
-            message: `${variable} cannot be modified`,
-          });
-          if (
-            effect.kind === 'Mutate' &&
-            effect.reason?.kind === 'AssignCurrentProperty'
-          ) {
-            diagnostic.withDetail({
-              kind: 'hint',
-              message: `Hint: If this value is a Ref (value returned by \`useRef()\`), rename the variable to end in "Ref".`,
-            });
-          }
           applyEffect(
             context,
             state,
@@ -1108,7 +1075,15 @@ function applyEffect(
                   ? 'MutateFrozen'
                   : 'MutateGlobal',
               place: effect.value,
-              error: diagnostic,
+              error: CompilerDiagnostic.create({
+                severity: ErrorSeverity.InvalidReact,
+                category: 'This value cannot be modified',
+                description: `${reason}.`,
+              }).withDetail({
+                kind: 'error',
+                loc: effect.value.loc,
+                message: `${variable} cannot be modified`,
+              }),
             },
             initialized,
             effects,
@@ -1705,15 +1680,7 @@ function computeSignatureForInstruction(
     }
     case 'PropertyStore':
     case 'ComputedStore': {
-      const mutationReason: MutationReason | null =
-        value.kind === 'PropertyStore' && value.property === 'current'
-          ? {kind: 'AssignCurrentProperty'}
-          : null;
-      effects.push({
-        kind: 'Mutate',
-        value: value.object,
-        reason: mutationReason,
-      });
+      effects.push({kind: 'Mutate', value: value.object});
       effects.push({
         kind: 'Capture',
         from: value.value,

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

@@ -21,6 +21,7 @@ import {
   isStableType,
   isStableTypeContainer,
   isUseOperator,
+  isUseRefType,
 } from '../HIR';
 import {PostDominator} from '../HIR/Dominator';
 import {
@@ -69,6 +70,13 @@ class StableSidemap {
               isStable: false,
             });
           }
+        } else if (
+          this.env.config.enableTreatRefLikeIdentifiersAsRefs &&
+          isUseRefType(lvalue.identifier)
+        ) {
+          this.map.set(lvalue.identifier.id, {
+            isStable: true,
+          });
         }
         break;
       }

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

@@ -237,7 +237,6 @@ function emitSelectorFn(env: Environment, keys: Array<string>): Instruction {
     terminal: {
       id: makeInstructionId(0),
       kind: 'return',
-      returnVariant: 'Explicit',
       loc: GeneratedSource,
       value: arrayInstr.lvalue,
       effects: null,

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

@@ -352,7 +352,6 @@ function emitOutlinedFn(
     terminal: {
       id: makeInstructionId(0),
       kind: 'return',
-      returnVariant: 'Explicit',
       loc: GeneratedSource,
       value: instructions.at(-1)!.lvalue,
       effects: null,

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

@@ -119,7 +119,6 @@ class FindLastUsageVisitor extends ReactiveFunctionVisitor<void> {
 
 class Transform extends ReactiveFunctionTransform<ReactiveScopeDependencies | null> {
   lastUsage: Map<DeclarationId, InstructionId>;
-  temporaries: Map<DeclarationId, DeclarationId> = new Map();
 
   constructor(lastUsage: Map<DeclarationId, InstructionId>) {
     super();
@@ -216,12 +215,6 @@ class Transform extends ReactiveFunctionTransform<ReactiveScopeDependencies | nu
                 current.lvalues.add(
                   instr.instruction.lvalue.identifier.declarationId,
                 );
-                if (instr.instruction.value.kind === 'LoadLocal') {
-                  this.temporaries.set(
-                    instr.instruction.lvalue.identifier.declarationId,
-                    instr.instruction.value.place.identifier.declarationId,
-                  );
-                }
               }
               break;
             }
@@ -243,13 +236,6 @@ class Transform extends ReactiveFunctionTransform<ReactiveScopeDependencies | nu
                   )) {
                     current.lvalues.add(lvalue.identifier.declarationId);
                   }
-                  this.temporaries.set(
-                    instr.instruction.value.lvalue.place.identifier
-                      .declarationId,
-                    this.temporaries.get(
-                      instr.instruction.value.value.identifier.declarationId,
-                    ) ?? instr.instruction.value.value.identifier.declarationId,
-                  );
                 } else {
                   log(
                     `Reset scope @${current.block.scope.id} from StoreLocal in [${instr.instruction.id}]`,
@@ -274,7 +260,7 @@ class Transform extends ReactiveFunctionTransform<ReactiveScopeDependencies | nu
         case 'scope': {
           if (
             current !== null &&
-            canMergeScopes(current.block, instr, this.temporaries) &&
+            canMergeScopes(current.block, instr) &&
             areLValuesLastUsedByScope(
               instr.scope,
               current.lvalues,
@@ -440,7 +426,6 @@ function areLValuesLastUsedByScope(
 function canMergeScopes(
   current: ReactiveScopeBlock,
   next: ReactiveScopeBlock,
-  temporaries: Map<DeclarationId, DeclarationId>,
 ): boolean {
   // Don't merge scopes with reassignments
   if (
@@ -480,14 +465,11 @@ function canMergeScopes(
     (next.scope.dependencies.size !== 0 &&
       [...next.scope.dependencies].every(
         dep =>
-          dep.path.length === 0 &&
           isAlwaysInvalidatingType(dep.identifier.type) &&
           Iterable_some(
             current.scope.declarations.values(),
             decl =>
-              decl.identifier.declarationId === dep.identifier.declarationId ||
-              decl.identifier.declarationId ===
-                temporaries.get(dep.identifier.declarationId),
+              decl.identifier.declarationId === dep.identifier.declarationId,
           ),
       ))
   ) {
@@ -495,16 +477,12 @@ function canMergeScopes(
     return true;
   }
   log(`  cannot merge scopes:`);
-  log(
-    `  ${printReactiveScopeSummary(current.scope)} ${[...current.scope.declarations.values()].map(decl => decl.identifier.declarationId)}`,
-  );
-  log(
-    `  ${printReactiveScopeSummary(next.scope)} ${[...next.scope.dependencies].map(dep => `${dep.identifier.declarationId} ${temporaries.get(dep.identifier.declarationId) ?? dep.identifier.declarationId}`)}`,
-  );
+  log(`  ${printReactiveScopeSummary(current.scope)}`);
+  log(`  ${printReactiveScopeSummary(next.scope)}`);
   return false;
 }
 
-export function isAlwaysInvalidatingType(type: Type): boolean {
+function isAlwaysInvalidatingType(type: Type): boolean {
   switch (type.kind) {
     case 'Object': {
       switch (type.shapeId) {

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

@@ -451,18 +451,6 @@ function* generateInstructionTypes(
 
     case 'JsxExpression':
     case 'JsxFragment': {
-      if (env.config.enableTreatRefLikeIdentifiersAsRefs) {
-        if (value.kind === 'JsxExpression') {
-          for (const prop of value.props) {
-            if (prop.kind === 'JsxAttribute' && prop.name === 'ref') {
-              yield equation(prop.place.identifier.type, {
-                kind: 'Object',
-                shapeId: BuiltInUseRefId,
-              });
-            }
-          }
-        }
-      }
       yield equation(left, {kind: 'Object', shapeId: BuiltInJsxId});
       break;
     }
@@ -478,36 +466,7 @@ function* generateInstructionTypes(
       yield equation(left, returnType);
       break;
     }
-    case 'PropertyStore': {
-      /**
-       * Infer types based on assignments to known object properties
-       * This is important for refs, where assignment to `<maybeRef>.current`
-       * can help us infer that an object itself is a ref
-       */
-      yield equation(
-        /**
-         * Our property type declarations are best-effort and we haven't tested
-         * using them to drive inference of rvalues from lvalues. We want to emit
-         * a Property type in order to infer refs from `.current` accesses, but
-         * stay conservative by not otherwise inferring anything about rvalues.
-         * So we use a dummy type here.
-         *
-         * TODO: consider using the rvalue type here
-         */
-        makeType(),
-        // unify() only handles properties in the second position
-        {
-          kind: 'Property',
-          objectType: value.object.identifier.type,
-          objectName: getName(names, value.object.identifier.id),
-          propertyName: {
-            kind: 'literal',
-            value: value.property,
-          },
-        },
-      );
-      break;
-    }
+    case 'PropertyStore':
     case 'DeclareLocal':
     case 'RegExpLiteral':
     case 'MetaProperty':

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

@@ -0,0 +1,110 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {HIRFunction, IdentifierId, Type, typeEquals} from '../HIR';
+
+/**
+ * Temporary workaround for InferTypes not propagating the types of phis.
+ * Previously, LeaveSSA would replace all the identifiers for each phi (operands and
+ * the phi itself) with a single "canonical" identifier, generally chosen as the first
+ * operand to flow into the phi. In case of a phi whose operand was a phi, this could
+ * sometimes be an operand from the earlier phi.
+ *
+ * As a result, even though InferTypes did not propagate types for phis, LeaveSSA
+ * could end up replacing the phi Identifier with another identifer from an operand,
+ * which _did_ have a type inferred.
+ *
+ * This didn't affect the initial construction of mutable ranges because InferMutableRanges
+ * runs before LeaveSSA - thus, the types propagated by LeaveSSA only affected later optimizations,
+ * notably MergeScopesThatInvalidateTogether which uses type to determine if a scope's output
+ * will always invalidate with its input.
+ *
+ * The long-term correct approach is to update InferTypes to infer the types of phis,
+ * but this is complicated because InferMutableRanges inadvertently depends on phis
+ * never having a known type, such that a Store effect cannot occur on a phi value.
+ * Once we fix InferTypes to infer phi types, then we'll also have to update InferMutableRanges
+ * to handle this case.
+ *
+ * As a temporary workaround, this pass propagates the type of phis and can be called
+ * safely *after* InferMutableRanges. Unlike LeaveSSA, this pass only propagates the
+ * type if all operands have the same type, it's its more correct.
+ */
+export function propagatePhiTypes(fn: HIRFunction): void {
+  /**
+   * We track which SSA ids have had their types propagated to handle nested ternaries,
+   * see the StoreLocal handling below
+   */
+  const propagated = new Set<IdentifierId>();
+  for (const [, block] of fn.body.blocks) {
+    for (const phi of block.phis) {
+      /*
+       * We replicate the previous LeaveSSA behavior and only propagate types for
+       * unnamed variables. LeaveSSA would have chosen one of the operands as the
+       * canonical id and taken its type as the type of all identifiers. We're
+       * more conservative and only propagate if the types are the same and the
+       * phi didn't have a type inferred.
+       *
+       * Note that this can change output slightly in cases such as
+       * `cond ? <div /> : null`.
+       *
+       * Previously the first operand's type (BuiltInJsx) would have been propagated,
+       * and this expression may have been merged with subsequent reactive scopes
+       * since it appears (based on that type) to always invalidate.
+       *
+       * But the correct type is `BuiltInJsx | null`, which we can't express and
+       * so leave as a generic `Type`, which does not always invalidate and therefore
+       * does not merge with subsequent scopes.
+       *
+       * We also don't propagate scopes for named variables, to preserve compatibility
+       * with previous LeaveSSA behavior.
+       */
+      if (
+        phi.place.identifier.type.kind !== 'Type' ||
+        phi.place.identifier.name !== null
+      ) {
+        continue;
+      }
+      let type: Type | null = null;
+      for (const [, operand] of phi.operands) {
+        if (type === null) {
+          type = operand.identifier.type;
+        } else if (!typeEquals(type, operand.identifier.type)) {
+          type = null;
+          break;
+        }
+      }
+      if (type !== null) {
+        phi.place.identifier.type = type;
+        propagated.add(phi.place.identifier.id);
+      }
+    }
+    for (const instr of block.instructions) {
+      const {value} = instr;
+      switch (value.kind) {
+        case 'StoreLocal': {
+          /**
+           * Nested ternaries can lower to a form with an intermediate StoreLocal where
+           * the value.lvalue is the temporary of the outer ternary, and the value.value
+           * is the result of the inner ternary.
+           *
+           * This is a common pattern in practice and easy enough to support. Again, the
+           * long-term approach is to update InferTypes and InferMutableRanges.
+           */
+          const lvalue = value.lvalue.place;
+          if (
+            propagated.has(value.value.identifier.id) &&
+            lvalue.identifier.type.kind === 'Type' &&
+            lvalue.identifier.name === null
+          ) {
+            lvalue.identifier.type = value.value.identifier.type;
+            propagated.add(lvalue.identifier.id);
+          }
+        }
+      }
+    }
+  }
+}

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

@@ -78,10 +78,6 @@ export default class DisjointSet<T> {
     return root;
   }
 
-  has(item: T): boolean {
-    return this.#entries.has(item);
-  }
-
   /*
    * Forces the set into canonical form, ie with all items pointing directly to
    * their root, and returns a Map representing the mapping of items to their roots.

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

@@ -1,87 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-/**
- * https://tc39.es/ecma262/multipage/ecmascript-language-lexical-grammar.html#sec-keywords-and-reserved-words
- */
-
-/**
- * Note: `await` and `yield` are contextually allowed as identifiers.
- *   await: reserved inside async functions and modules
- *   yield: reserved inside generator functions
- *
- * Note: `async` is not reserved.
- */
-const RESERVED_WORDS = new Set([
-  'break',
-  'case',
-  'catch',
-  'class',
-  'const',
-  'continue',
-  'debugger',
-  'default',
-  'delete',
-  'do',
-  'else',
-  'enum',
-  'export',
-  'extends',
-  'false',
-  'finally',
-  'for',
-  'function',
-  'if',
-  'import',
-  'in',
-  'instanceof',
-  'new',
-  'null',
-  'return',
-  'super',
-  'switch',
-  'this',
-  'throw',
-  'true',
-  'try',
-  'typeof',
-  'var',
-  'void',
-  'while',
-  'with',
-]);
-
-/**
- * Reserved when a module has a 'use strict' directive.
- */
-const STRICT_MODE_RESERVED_WORDS = new Set([
-  'let',
-  'static',
-  'implements',
-  'interface',
-  'package',
-  'private',
-  'protected',
-  'public',
-]);
-/**
- * The names arguments and eval are not keywords, but they are subject to some restrictions in
- * strict mode code.
- */
-const STRICT_MODE_RESTRICTED_WORDS = new Set(['eval', 'arguments']);
-
-/**
- * Conservative check for whether an identifer name is reserved or not. We assume that code is
- * written with strict mode.
- */
-export function isReservedWord(identifierName: string): boolean {
-  return (
-    RESERVED_WORDS.has(identifierName) ||
-    STRICT_MODE_RESERVED_WORDS.has(identifierName) ||
-    STRICT_MODE_RESTRICTED_WORDS.has(identifierName)
-  );
-}

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

@@ -33,12 +33,12 @@ export function assertExhaustive(_: never, errorMsg: string): never {
 // Modifies @param array in place, retaining only the items where the predicate returns true.
 export function retainWhere<T>(
   array: Array<T>,
-  predicate: (item: T, index: number) => boolean,
+  predicate: (item: T) => boolean,
 ): void {
   let writeIndex = 0;
   for (let readIndex = 0; readIndex < array.length; readIndex++) {
     const item = array[readIndex];
-    if (predicate(item, readIndex) === true) {
+    if (predicate(item) === true) {
       array[writeIndex++] = item;
     }
   }

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

@@ -1,230 +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 {CompilerError, ErrorSeverity, SourceLocation} from '..';
-import {
-  ArrayExpression,
-  BlockId,
-  FunctionExpression,
-  HIRFunction,
-  IdentifierId,
-  isSetStateType,
-  isUseEffectHookType,
-} from '../HIR';
-import {
-  eachInstructionValueOperand,
-  eachTerminalOperand,
-} from '../HIR/visitors';
-
-/**
- * Validates that useEffect is not used for derived computations which could/should
- * be performed in render.
- *
- * See https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state
- *
- * Example:
- *
- * ```
- * // 🔴 Avoid: redundant state and unnecessary Effect
- * const [fullName, setFullName] = useState('');
- * useEffect(() => {
- *   setFullName(firstName + ' ' + lastName);
- * }, [firstName, lastName]);
- * ```
- *
- * Instead use:
- *
- * ```
- * // ✅ Good: calculated during rendering
- * const fullName = firstName + ' ' + lastName;
- * ```
- */
-export function validateNoDerivedComputationsInEffects(fn: HIRFunction): void {
-  const candidateDependencies: Map<IdentifierId, ArrayExpression> = new Map();
-  const functions: Map<IdentifierId, FunctionExpression> = new Map();
-  const locals: Map<IdentifierId, IdentifierId> = new Map();
-
-  const errors = new CompilerError();
-
-  for (const block of fn.body.blocks.values()) {
-    for (const instr of block.instructions) {
-      const {lvalue, value} = instr;
-      if (value.kind === 'LoadLocal') {
-        locals.set(lvalue.identifier.id, value.place.identifier.id);
-      } else if (value.kind === 'ArrayExpression') {
-        candidateDependencies.set(lvalue.identifier.id, value);
-      } else if (value.kind === 'FunctionExpression') {
-        functions.set(lvalue.identifier.id, value);
-      } else if (
-        value.kind === 'CallExpression' ||
-        value.kind === 'MethodCall'
-      ) {
-        const callee =
-          value.kind === 'CallExpression' ? value.callee : value.property;
-        if (
-          isUseEffectHookType(callee.identifier) &&
-          value.args.length === 2 &&
-          value.args[0].kind === 'Identifier' &&
-          value.args[1].kind === 'Identifier'
-        ) {
-          const effectFunction = functions.get(value.args[0].identifier.id);
-          const deps = candidateDependencies.get(value.args[1].identifier.id);
-          if (
-            effectFunction != null &&
-            deps != null &&
-            deps.elements.length !== 0 &&
-            deps.elements.every(element => element.kind === 'Identifier')
-          ) {
-            const dependencies: Array<IdentifierId> = deps.elements.map(dep => {
-              CompilerError.invariant(dep.kind === 'Identifier', {
-                reason: `Dependency is checked as a place above`,
-                loc: value.loc,
-              });
-              return locals.get(dep.identifier.id) ?? dep.identifier.id;
-            });
-            validateEffect(
-              effectFunction.loweredFunc.func,
-              dependencies,
-              errors,
-            );
-          }
-        }
-      }
-    }
-  }
-  if (errors.hasErrors()) {
-    throw errors;
-  }
-}
-
-function validateEffect(
-  effectFunction: HIRFunction,
-  effectDeps: Array<IdentifierId>,
-  errors: CompilerError,
-): void {
-  for (const operand of effectFunction.context) {
-    if (isSetStateType(operand.identifier)) {
-      continue;
-    } else if (effectDeps.find(dep => dep === operand.identifier.id) != null) {
-      continue;
-    } else {
-      // Captured something other than the effect dep or setState
-      return;
-    }
-  }
-  for (const dep of effectDeps) {
-    if (
-      effectFunction.context.find(operand => operand.identifier.id === dep) ==
-      null
-    ) {
-      // effect dep wasn't actually used in the function
-      return;
-    }
-  }
-
-  const seenBlocks: Set<BlockId> = new Set();
-  const values: Map<IdentifierId, Array<IdentifierId>> = new Map();
-  for (const dep of effectDeps) {
-    values.set(dep, [dep]);
-  }
-
-  const setStateLocations: Array<SourceLocation> = [];
-  for (const block of effectFunction.body.blocks.values()) {
-    for (const pred of block.preds) {
-      if (!seenBlocks.has(pred)) {
-        // skip if block has a back edge
-        return;
-      }
-    }
-    for (const phi of block.phis) {
-      const aggregateDeps: Set<IdentifierId> = new Set();
-      for (const operand of phi.operands.values()) {
-        const deps = values.get(operand.identifier.id);
-        if (deps != null) {
-          for (const dep of deps) {
-            aggregateDeps.add(dep);
-          }
-        }
-      }
-      if (aggregateDeps.size !== 0) {
-        values.set(phi.place.identifier.id, Array.from(aggregateDeps));
-      }
-    }
-    for (const instr of block.instructions) {
-      switch (instr.value.kind) {
-        case 'Primitive':
-        case 'JSXText':
-        case 'LoadGlobal': {
-          break;
-        }
-        case 'LoadLocal': {
-          const deps = values.get(instr.value.place.identifier.id);
-          if (deps != null) {
-            values.set(instr.lvalue.identifier.id, deps);
-          }
-          break;
-        }
-        case 'ComputedLoad':
-        case 'PropertyLoad':
-        case 'BinaryExpression':
-        case 'TemplateLiteral':
-        case 'CallExpression':
-        case 'MethodCall': {
-          const aggregateDeps: Set<IdentifierId> = new Set();
-          for (const operand of eachInstructionValueOperand(instr.value)) {
-            const deps = values.get(operand.identifier.id);
-            if (deps != null) {
-              for (const dep of deps) {
-                aggregateDeps.add(dep);
-              }
-            }
-          }
-          if (aggregateDeps.size !== 0) {
-            values.set(instr.lvalue.identifier.id, Array.from(aggregateDeps));
-          }
-
-          if (
-            instr.value.kind === 'CallExpression' &&
-            isSetStateType(instr.value.callee.identifier) &&
-            instr.value.args.length === 1 &&
-            instr.value.args[0].kind === 'Identifier'
-          ) {
-            const deps = values.get(instr.value.args[0].identifier.id);
-            if (deps != null && new Set(deps).size === effectDeps.length) {
-              setStateLocations.push(instr.value.callee.loc);
-            } else {
-              // doesn't depend on any deps
-              return;
-            }
-          }
-          break;
-        }
-        default: {
-          return;
-        }
-      }
-    }
-    for (const operand of eachTerminalOperand(block.terminal)) {
-      if (values.has(operand.identifier.id)) {
-        //
-        return;
-      }
-    }
-    seenBlocks.add(block.id);
-  }
-
-  for (const loc of setStateLocations) {
-    errors.push({
-      reason:
-        'Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)',
-      description: null,
-      severity: ErrorSeverity.InvalidReact,
-      loc,
-      suggestions: null,
-    });
-  }
-}

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

@@ -5,11 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {
-  CompilerDiagnostic,
-  CompilerError,
-  ErrorSeverity,
-} from '../CompilerError';
+import {CompilerError, ErrorSeverity} from '../CompilerError';
 import {
   BlockId,
   HIRFunction,
@@ -27,7 +23,6 @@ import {
   eachTerminalOperand,
 } from '../HIR/visitors';
 import {Err, Ok, Result} from '../Utils/Result';
-import {retainWhere} from '../Utils/utils';
 
 /**
  * Validates that a function does not access a ref value during render. This includes a partial check
@@ -80,18 +75,8 @@ type RefAccessRefType =
 
 type RefFnType = {readRefEffect: boolean; returnType: RefAccessType};
 
-class Env {
+class Env extends Map<IdentifierId, RefAccessType> {
   #changed = false;
-  #data: Map<IdentifierId, RefAccessType> = new Map();
-  #temporaries: Map<IdentifierId, Place> = new Map();
-
-  lookup(place: Place): Place {
-    return this.#temporaries.get(place.identifier.id) ?? place;
-  }
-
-  define(place: Place, value: Place): void {
-    this.#temporaries.set(place.identifier.id, value);
-  }
 
   resetChanged(): void {
     this.#changed = false;
@@ -101,14 +86,8 @@ class Env {
     return this.#changed;
   }
 
-  get(key: IdentifierId): RefAccessType | undefined {
-    const operandId = this.#temporaries.get(key)?.identifier.id ?? key;
-    return this.#data.get(operandId);
-  }
-
-  set(key: IdentifierId, value: RefAccessType): this {
-    const operandId = this.#temporaries.get(key)?.identifier.id ?? key;
-    const cur = this.#data.get(operandId);
+  override set(key: IdentifierId, value: RefAccessType): this {
+    const cur = this.get(key);
     const widenedValue = joinRefAccessTypes(value, cur ?? {kind: 'None'});
     if (
       !(cur == null && widenedValue.kind === 'None') &&
@@ -116,8 +95,7 @@ class Env {
     ) {
       this.#changed = true;
     }
-    this.#data.set(operandId, widenedValue);
-    return this;
+    return super.set(key, widenedValue);
   }
 }
 
@@ -125,48 +103,9 @@ export function validateNoRefAccessInRender(
   fn: HIRFunction,
 ): Result<void, CompilerError> {
   const env = new Env();
-  collectTemporariesSidemap(fn, env);
   return validateNoRefAccessInRenderImpl(fn, env).map(_ => undefined);
 }
 
-function collectTemporariesSidemap(fn: HIRFunction, env: Env): void {
-  for (const block of fn.body.blocks.values()) {
-    for (const instr of block.instructions) {
-      const {lvalue, value} = instr;
-      switch (value.kind) {
-        case 'LoadLocal': {
-          const temp = env.lookup(value.place);
-          if (temp != null) {
-            env.define(lvalue, temp);
-          }
-          break;
-        }
-        case 'StoreLocal': {
-          const temp = env.lookup(value.value);
-          if (temp != null) {
-            env.define(lvalue, temp);
-            env.define(value.lvalue.place, temp);
-          }
-          break;
-        }
-        case 'PropertyLoad': {
-          if (
-            isUseRefType(value.object.identifier) &&
-            value.property === 'current'
-          ) {
-            continue;
-          }
-          const temp = env.lookup(value.object);
-          if (temp != null) {
-            env.define(lvalue, temp);
-          }
-          break;
-        }
-      }
-    }
-  }
-}
-
 function refTypeOfType(place: Place): RefAccessType {
   if (isRefValueType(place.identifier)) {
     return {kind: 'RefValue'};
@@ -319,27 +258,12 @@ function validateNoRefAccessInRenderImpl(
     env.set(place.identifier.id, type);
   }
 
-  const interpolatedAsJsx = new Set<IdentifierId>();
-  for (const block of fn.body.blocks.values()) {
-    for (const instr of block.instructions) {
-      const {value} = instr;
-      if (value.kind === 'JsxExpression' || value.kind === 'JsxFragment') {
-        if (value.children != null) {
-          for (const child of value.children) {
-            interpolatedAsJsx.add(child.identifier.id);
-          }
-        }
-      }
-    }
-  }
-
   for (let i = 0; (i == 0 || env.hasChanged()) && i < 10; i++) {
     env.resetChanged();
     returnValues = [];
-    const safeBlocks: Array<{block: BlockId; ref: RefId}> = [];
+    const safeBlocks = new Map<BlockId, RefId>();
     const errors = new CompilerError();
     for (const [, block] of fn.body.blocks) {
-      retainWhere(safeBlocks, entry => entry.block !== block.id);
       for (const phi of block.phis) {
         env.set(
           phi.place.identifier.id,
@@ -461,79 +385,28 @@ function validateNoRefAccessInRenderImpl(
             const hookKind = getHookKindForType(fn.env, callee.identifier.type);
             let returnType: RefAccessType = {kind: 'None'};
             const fnType = env.get(callee.identifier.id);
-            let didError = false;
             if (fnType?.kind === 'Structure' && fnType.fn !== null) {
               returnType = fnType.fn.returnType;
               if (fnType.fn.readRefEffect) {
-                didError = true;
-                errors.pushDiagnostic(
-                  CompilerDiagnostic.create({
-                    severity: ErrorSeverity.InvalidReact,
-                    category: 'Cannot access refs during render',
-                    description: ERROR_DESCRIPTION,
-                  }).withDetail({
-                    kind: 'error',
-                    loc: callee.loc,
-                    message: `This function accesses a ref value`,
-                  }),
-                );
+                errors.push({
+                  severity: ErrorSeverity.InvalidReact,
+                  reason:
+                    'This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef)',
+                  loc: callee.loc,
+                  description:
+                    callee.identifier.name !== null &&
+                    callee.identifier.name.kind === 'named'
+                      ? `Function \`${callee.identifier.name.value}\` accesses a ref`
+                      : null,
+                  suggestions: null,
+                });
               }
             }
-            /*
-             * If we already reported an error on this instruction, don't report
-             * duplicate errors
-             */
-            if (!didError) {
-              const isRefLValue = isUseRefType(instr.lvalue.identifier);
-              for (const operand of eachInstructionValueOperand(instr.value)) {
-                /**
-                 * By default we check that function call operands are not refs,
-                 * ref values, or functions that can access refs.
-                 */
-                if (
-                  isRefLValue ||
-                  (hookKind != null &&
-                    hookKind !== 'useState' &&
-                    hookKind !== 'useReducer')
-                ) {
-                  /**
-                   * Special cases:
-                   *
-                   * 1. the lvalue is a ref
-                   * In general passing a ref to a function may access that ref
-                   * value during render, so we disallow it.
-                   *
-                   * The main exception is the "mergeRefs" pattern, ie a function
-                   * that accepts multiple refs as arguments (or an array of refs)
-                   * and returns a new, aggregated ref. If the lvalue is a ref,
-                   * we assume that the user is doing this pattern and allow passing
-                   * refs.
-                   *
-                   * Eg `const mergedRef = mergeRefs(ref1, ref2)`
-                   *
-                   * 2. calling hooks
-                   *
-                   * Hooks are independently checked to ensure they don't access refs
-                   * during render.
-                   */
-                  validateNoDirectRefValueAccess(errors, operand, env);
-                } else if (interpolatedAsJsx.has(instr.lvalue.identifier.id)) {
-                  /**
-                   * Special case: the lvalue is passed as a jsx child
-                   *
-                   * For example `<Foo>{renderHelper(ref)}</Foo>`. Here we have more
-                   * context and infer that the ref is being passed to a component-like
-                   * render function which attempts to obey the rules.
-                   */
-                  validateNoRefValueAccess(errors, env, operand);
-                } else {
-                  validateNoRefPassedToFunction(
-                    errors,
-                    env,
-                    operand,
-                    operand.loc,
-                  );
-                }
+            for (const operand of eachInstructionValueOperand(instr.value)) {
+              if (hookKind != null) {
+                validateNoDirectRefValueAccess(errors, operand, env);
+              } else {
+                validateNoRefAccess(errors, env, operand, operand.loc);
               }
             }
             env.set(instr.lvalue.identifier.id, returnType);
@@ -566,39 +439,23 @@ function validateNoRefAccessInRenderImpl(
           case 'PropertyStore':
           case 'ComputedDelete':
           case 'ComputedStore': {
+            const safe = safeBlocks.get(block.id);
             const target = env.get(instr.value.object.identifier.id);
-            let safe: (typeof safeBlocks)['0'] | null | undefined = null;
             if (
               instr.value.kind === 'PropertyStore' &&
-              target != null &&
-              target.kind === 'Ref'
+              safe != null &&
+              target?.kind === 'Ref' &&
+              target.refId === safe
             ) {
-              safe = safeBlocks.find(entry => entry.ref === target.refId);
-            }
-            if (safe != null) {
-              retainWhere(safeBlocks, entry => entry !== safe);
+              safeBlocks.delete(block.id);
             } else {
-              validateNoRefUpdate(errors, env, instr.value.object, instr.loc);
+              validateNoRefAccess(errors, env, instr.value.object, instr.loc);
             }
-            if (
-              instr.value.kind === 'ComputedDelete' ||
-              instr.value.kind === 'ComputedStore'
-            ) {
-              validateNoRefValueAccess(errors, env, instr.value.property);
-            }
-            if (
-              instr.value.kind === 'ComputedStore' ||
-              instr.value.kind === 'PropertyStore'
-            ) {
-              validateNoDirectRefValueAccess(errors, instr.value.value, env);
-              const type = env.get(instr.value.value.identifier.id);
-              if (type != null && type.kind === 'Structure') {
-                let objectType: RefAccessType = type;
-                if (target != null) {
-                  objectType = joinRefAccessTypes(objectType, target);
-                }
-                env.set(instr.value.object.identifier.id, objectType);
+            for (const operand of eachInstructionValueOperand(instr.value)) {
+              if (operand === instr.value.object) {
+                continue;
               }
+              validateNoRefValueAccess(errors, env, operand);
             }
             break;
           }
@@ -678,11 +535,8 @@ function validateNoRefAccessInRenderImpl(
 
       if (block.terminal.kind === 'if') {
         const test = env.get(block.terminal.test.identifier.id);
-        if (
-          test?.kind === 'Guard' &&
-          safeBlocks.find(entry => entry.ref === test.refId) == null
-        ) {
-          safeBlocks.push({block: block.terminal.fallthrough, ref: test.refId});
+        if (test?.kind === 'Guard') {
+          safeBlocks.set(block.terminal.consequent, test.refId);
         }
       }
 
@@ -729,17 +583,18 @@ function destructure(
 
 function guardCheck(errors: CompilerError, operand: Place, env: Env): void {
   if (env.get(operand.identifier.id)?.kind === 'Guard') {
-    errors.pushDiagnostic(
-      CompilerDiagnostic.create({
-        severity: ErrorSeverity.InvalidReact,
-        category: 'Cannot access refs during render',
-        description: ERROR_DESCRIPTION,
-      }).withDetail({
-        kind: 'error',
-        loc: operand.loc,
-        message: `Cannot access ref value during render`,
-      }),
-    );
+    errors.push({
+      severity: ErrorSeverity.InvalidReact,
+      reason:
+        'Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)',
+      loc: operand.loc,
+      description:
+        operand.identifier.name !== null &&
+        operand.identifier.name.kind === 'named'
+          ? `Cannot access ref value \`${operand.identifier.name.value}\``
+          : null,
+      suggestions: null,
+    });
   }
 }
 
@@ -753,21 +608,22 @@ function validateNoRefValueAccess(
     type?.kind === 'RefValue' ||
     (type?.kind === 'Structure' && type.fn?.readRefEffect)
   ) {
-    errors.pushDiagnostic(
-      CompilerDiagnostic.create({
-        severity: ErrorSeverity.InvalidReact,
-        category: 'Cannot access refs during render',
-        description: ERROR_DESCRIPTION,
-      }).withDetail({
-        kind: 'error',
-        loc: (type.kind === 'RefValue' && type.loc) || operand.loc,
-        message: `Cannot access ref value during render`,
-      }),
-    );
+    errors.push({
+      severity: ErrorSeverity.InvalidReact,
+      reason:
+        'Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)',
+      loc: (type.kind === 'RefValue' && type.loc) || operand.loc,
+      description:
+        operand.identifier.name !== null &&
+        operand.identifier.name.kind === 'named'
+          ? `Cannot access ref value \`${operand.identifier.name.value}\``
+          : null,
+      suggestions: null,
+    });
   }
 }
 
-function validateNoRefPassedToFunction(
+function validateNoRefAccess(
   errors: CompilerError,
   env: Env,
   operand: Place,
@@ -779,39 +635,18 @@ function validateNoRefPassedToFunction(
     type?.kind === 'RefValue' ||
     (type?.kind === 'Structure' && type.fn?.readRefEffect)
   ) {
-    errors.pushDiagnostic(
-      CompilerDiagnostic.create({
-        severity: ErrorSeverity.InvalidReact,
-        category: 'Cannot access refs during render',
-        description: ERROR_DESCRIPTION,
-      }).withDetail({
-        kind: 'error',
-        loc: (type.kind === 'RefValue' && type.loc) || loc,
-        message: `Passing a ref to a function may read its value during render`,
-      }),
-    );
-  }
-}
-
-function validateNoRefUpdate(
-  errors: CompilerError,
-  env: Env,
-  operand: Place,
-  loc: SourceLocation,
-): void {
-  const type = destructure(env.get(operand.identifier.id));
-  if (type?.kind === 'Ref' || type?.kind === 'RefValue') {
-    errors.pushDiagnostic(
-      CompilerDiagnostic.create({
-        severity: ErrorSeverity.InvalidReact,
-        category: 'Cannot access refs during render',
-        description: ERROR_DESCRIPTION,
-      }).withDetail({
-        kind: 'error',
-        loc: (type.kind === 'RefValue' && type.loc) || loc,
-        message: `Cannot update ref during render`,
-      }),
-    );
+    errors.push({
+      severity: ErrorSeverity.InvalidReact,
+      reason:
+        'Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)',
+      loc: (type.kind === 'RefValue' && type.loc) || loc,
+      description:
+        operand.identifier.name !== null &&
+        operand.identifier.name.kind === 'named'
+          ? `Cannot access ref value \`${operand.identifier.name.value}\``
+          : null,
+      suggestions: null,
+    });
   }
 }
 
@@ -822,22 +657,17 @@ function validateNoDirectRefValueAccess(
 ): void {
   const type = destructure(env.get(operand.identifier.id));
   if (type?.kind === 'RefValue') {
-    errors.pushDiagnostic(
-      CompilerDiagnostic.create({
-        severity: ErrorSeverity.InvalidReact,
-        category: 'Cannot access refs during render',
-        description: ERROR_DESCRIPTION,
-      }).withDetail({
-        kind: 'error',
-        loc: type.loc ?? operand.loc,
-        message: `Cannot access ref value during render`,
-      }),
-    );
+    errors.push({
+      severity: ErrorSeverity.InvalidReact,
+      reason:
+        'Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)',
+      loc: type.loc ?? operand.loc,
+      description:
+        operand.identifier.name !== null &&
+        operand.identifier.name.kind === 'named'
+          ? `Cannot access ref value \`${operand.identifier.name.value}\``
+          : null,
+      suggestions: null,
+    });
   }
 }
-
-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 ' +
-  'not to update as expected (https://react.dev/reference/react/useRef)';

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

@@ -1,52 +0,0 @@
-
-## 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-assigning-ref-accessing-function-to-object-property-if-not-mutated.js

@@ -1,14 +0,0 @@
-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}],
-};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-merge-refs-pattern.expect.md

@@ -1,44 +0,0 @@
-
-## Input
-
-```javascript
-// @enableTreatRefLikeIdentifiersAsRefs @validateRefAccessDuringRender
-
-import {useRef} from 'react';
-
-function Component() {
-  const ref = useRef(null);
-  const ref2 = useRef(null);
-  const mergedRef = mergeRefs([ref], ref2);
-
-  return <Stringify ref={mergedRef} />;
-}
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime"; // @enableTreatRefLikeIdentifiersAsRefs @validateRefAccessDuringRender
-
-import { useRef } from "react";
-
-function Component() {
-  const $ = _c(1);
-  const ref = useRef(null);
-  const ref2 = useRef(null);
-  const mergedRef = mergeRefs([ref], ref2);
-  let t0;
-  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-    t0 = <Stringify ref={mergedRef} />;
-    $[0] = t0;
-  } else {
-    t0 = $[0];
-  }
-  return t0;
-}
-
-```
-      
-### Eval output
-(kind: exception) Fixture not implemented

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-merge-refs-pattern.js

@@ -1,11 +0,0 @@
-// @enableTreatRefLikeIdentifiersAsRefs @validateRefAccessDuringRender
-
-import {useRef} from 'react';
-
-function Component() {
-  const ref = useRef(null);
-  const ref2 = useRef(null);
-  const mergedRef = mergeRefs([ref], ref2);
-
-  return <Stringify ref={mergedRef} />;
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-passing-ref-to-render-helper-props-object.expect.md

@@ -1,45 +0,0 @@
-
-## Input
-
-```javascript
-// @enableTreatRefLikeIdentifiersAsRefs @validateRefAccessDuringRender
-
-import {useRef} from 'react';
-
-function Component(props) {
-  const ref = useRef(null);
-
-  return <Foo>{props.render({ref})}</Foo>;
-}
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime"; // @enableTreatRefLikeIdentifiersAsRefs @validateRefAccessDuringRender
-
-import { useRef } from "react";
-
-function Component(props) {
-  const $ = _c(3);
-  const ref = useRef(null);
-
-  const T0 = Foo;
-  const t0 = props.render({ ref });
-  let t1;
-  if ($[0] !== T0 || $[1] !== t0) {
-    t1 = <T0>{t0}</T0>;
-    $[0] = T0;
-    $[1] = t0;
-    $[2] = t1;
-  } else {
-    t1 = $[2];
-  }
-  return t1;
-}
-
-```
-      
-### Eval output
-(kind: exception) Fixture not implemented

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-passing-ref-to-render-helper-props-object.js

@@ -1,9 +0,0 @@
-// @enableTreatRefLikeIdentifiersAsRefs @validateRefAccessDuringRender
-
-import {useRef} from 'react';
-
-function Component(props) {
-  const ref = useRef(null);
-
-  return <Foo>{props.render({ref})}</Foo>;
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-passing-ref-to-render-helper.expect.md

@@ -1,49 +0,0 @@
-
-## Input
-
-```javascript
-// @enableTreatRefLikeIdentifiersAsRefs @validateRefAccessDuringRender
-
-import {useRef} from 'react';
-
-function Component(props) {
-  const ref = useRef(null);
-
-  return <Foo>{props.render(ref)}</Foo>;
-}
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime"; // @enableTreatRefLikeIdentifiersAsRefs @validateRefAccessDuringRender
-
-import { useRef } from "react";
-
-function Component(props) {
-  const $ = _c(4);
-  const ref = useRef(null);
-  let t0;
-  if ($[0] !== props.render) {
-    t0 = props.render(ref);
-    $[0] = props.render;
-    $[1] = t0;
-  } else {
-    t0 = $[1];
-  }
-  let t1;
-  if ($[2] !== t0) {
-    t1 = <Foo>{t0}</Foo>;
-    $[2] = t0;
-    $[3] = t1;
-  } else {
-    t1 = $[3];
-  }
-  return t1;
-}
-
-```
-      
-### Eval output
-(kind: exception) Fixture not implemented

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-passing-ref-to-render-helper.js

@@ -1,9 +0,0 @@
-// @enableTreatRefLikeIdentifiersAsRefs @validateRefAccessDuringRender
-
-import {useRef} from 'react';
-
-function Component(props) {
-  const ref = useRef(null);
-
-  return <Foo>{props.render(ref)}</Foo>;
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-ref-access-in-effect-indirect.expect.md

@@ -27,7 +27,6 @@ function Component() {
 }
 
 function Child({ref}) {
-  'use no memo';
   // This violates the rules of React, so we access the ref in a child
   // component
   return ref.current;
@@ -101,10 +100,8 @@ function Component() {
   return t6;
 }
 
-function Child({ ref }) {
-  "use no memo";
-  // This violates the rules of React, so we access the ref in a child
-  // component
+function Child(t0) {
+  const { ref } = t0;
   return ref.current;
 }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-ref-access-in-effect-indirect.js

@@ -23,7 +23,6 @@ function Component() {
 }
 
 function Child({ref}) {
-  'use no memo';
   // This violates the rules of React, so we access the ref in a child
   // component
   return ref.current;

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

@@ -23,7 +23,6 @@ function Component() {
 }
 
 function Child({ref}) {
-  'use no memo';
   // This violates the rules of React, so we access the ref in a child
   // component
   return ref.current;
@@ -87,10 +86,8 @@ function Component() {
   return t5;
 }
 
-function Child({ ref }) {
-  "use no memo";
-  // This violates the rules of React, so we access the ref in a child
-  // component
+function Child(t0) {
+  const { ref } = t0;
   return ref.current;
 }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-ref-access-in-effect.js

@@ -19,7 +19,6 @@ function Component() {
 }
 
 function Child({ref}) {
-  'use no memo';
   // This violates the rules of React, so we access the ref in a child
   // component
   return ref.current;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-ref-access-in-unused-callback-nested.expect.md

@@ -25,7 +25,6 @@ function Component() {
 }
 
 function Child({ref}) {
-  'use no memo';
   // This violates the rules of React, so we access the ref in a child
   // component
   return ref.current;
@@ -84,10 +83,8 @@ function Component() {
 }
 function _temp() {}
 
-function Child({ ref }) {
-  "use no memo";
-  // This violates the rules of React, so we access the ref in a child
-  // component
+function Child(t0) {
+  const { ref } = t0;
   return ref.current;
 }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-ref-access-in-unused-callback-nested.js

@@ -21,7 +21,6 @@ function Component() {
 }
 
 function Child({ref}) {
-  'use no memo';
   // This violates the rules of React, so we access the ref in a child
   // component
   return ref.current;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-ref-lazy-initialization-with-logical.expect.md

@@ -1,68 +0,0 @@
-
-## Input
-
-```javascript
-// @validateRefAccessDuringRender
-
-import {useRef} from 'react';
-
-function Component(props) {
-  const ref = useRef(null);
-  if (ref.current == null) {
-    // the logical means the ref write is in a different block
-    // from the if consequent. this tests that the "safe" blocks
-    // extend up to the if's fallthrough
-    ref.current = props.unknownKey ?? props.value;
-  }
-  return <Child ref={ref} />;
-}
-
-function Child({ref}) {
-  'use no memo';
-  return ref.current;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-};
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime"; // @validateRefAccessDuringRender
-
-import { useRef } from "react";
-
-function Component(props) {
-  const $ = _c(1);
-  const ref = useRef(null);
-  if (ref.current == null) {
-    ref.current = props.unknownKey ?? props.value;
-  }
-  let t0;
-  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-    t0 = <Child ref={ref} />;
-    $[0] = t0;
-  } else {
-    t0 = $[0];
-  }
-  return t0;
-}
-
-function Child({ ref }) {
-  "use no memo";
-  return ref.current;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{ value: 42 }],
-};
-
-```
-      
-### Eval output
-(kind: ok) 42

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/allow-ref-lazy-initialization-with-logical.js

@@ -1,24 +0,0 @@
-// @validateRefAccessDuringRender
-
-import {useRef} from 'react';
-
-function Component(props) {
-  const ref = useRef(null);
-  if (ref.current == null) {
-    // the logical means the ref write is in a different block
-    // from the if consequent. this tests that the "safe" blocks
-    // extend up to the if's fallthrough
-    ref.current = props.unknownKey ?? props.value;
-  }
-  return <Child ref={ref} />;
-}
-
-function Child({ref}) {
-  'use no memo';
-  return ref.current;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-};

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

@@ -19,7 +19,7 @@ function Component(props) {
 ```javascript
 import { c as _c } from "react/compiler-runtime";
 function Component(props) {
-  const $ = _c(5);
+  const $ = _c(7);
   let t0;
   if ($[0] !== props.x) {
     t0 = foo(props.x);
@@ -31,19 +31,26 @@ function Component(props) {
   const x = t0;
   let t1;
   if ($[2] !== props || $[3] !== x) {
-    const fn = function () {
+    t1 = function () {
       const arr = [...bar(props)];
       return arr.at(x);
     };
-
-    t1 = fn();
     $[2] = props;
     $[3] = x;
     $[4] = t1;
   } else {
     t1 = $[4];
   }
-  const fnResult = t1;
+  const fn = t1;
+  let t2;
+  if ($[5] !== fn) {
+    t2 = fn();
+    $[5] = fn;
+    $[6] = t2;
+  } else {
+    t2 = $[6];
+  }
+  const fnResult = t2;
   return fnResult;
 }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-map-captures-receiver-noAlias.expect.md

@@ -23,18 +23,34 @@ export const FIXTURE_ENTRYPOINT = {
 ```javascript
 import { c as _c } from "react/compiler-runtime";
 function Component(props) {
-  const $ = _c(2);
+  const $ = _c(6);
   let t0;
   if ($[0] !== props.a) {
-    const item = { a: props.a };
-    const items = [item];
-    t0 = items.map(_temp);
+    t0 = { a: props.a };
     $[0] = props.a;
     $[1] = t0;
   } else {
     t0 = $[1];
   }
-  const mapped = t0;
+  const item = t0;
+  let t1;
+  if ($[2] !== item) {
+    t1 = [item];
+    $[2] = item;
+    $[3] = t1;
+  } else {
+    t1 = $[3];
+  }
+  const items = t1;
+  let t2;
+  if ($[4] !== items) {
+    t2 = items.map(_temp);
+    $[4] = items;
+    $[5] = t2;
+  } else {
+    t2 = $[5];
+  }
+  const mapped = t2;
   return mapped;
 }
 function _temp(item_0) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/array-map-noAlias-escaping-function.expect.md

@@ -21,18 +21,26 @@ export const FIXTURE_ENTRYPOINT = {
 ```javascript
 import { c as _c } from "react/compiler-runtime";
 function Component(props) {
-  const $ = _c(2);
+  const $ = _c(4);
   const f = _temp;
   let t0;
   if ($[0] !== props.items) {
-    const x = [...props.items].map(f);
-    t0 = [x, f];
+    t0 = [...props.items].map(f);
     $[0] = props.items;
     $[1] = t0;
   } else {
     t0 = $[1];
   }
-  return t0;
+  const x = t0;
+  let t1;
+  if ($[2] !== x) {
+    t1 = [x, f];
+    $[2] = x;
+    $[3] = t1;
+  } else {
+    t1 = $[3];
+  }
+  return t1;
 }
 function _temp(item) {
   return item;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/capturing-arrow-function-1.expect.md

@@ -23,19 +23,27 @@ export const FIXTURE_ENTRYPOINT = {
 ```javascript
 import { c as _c } from "react/compiler-runtime";
 function component(a) {
-  const $ = _c(2);
+  const $ = _c(4);
   let t0;
   if ($[0] !== a) {
-    const z = { a };
-    t0 = () => {
-      console.log(z);
-    };
+    t0 = { a };
     $[0] = a;
     $[1] = t0;
   } else {
     t0 = $[1];
   }
-  const x = t0;
+  const z = t0;
+  let t1;
+  if ($[2] !== z) {
+    t1 = () => {
+      console.log(z);
+    };
+    $[2] = z;
+    $[3] = t1;
+  } else {
+    t1 = $[3];
+  }
+  const x = t1;
   return x;
 }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/capturing-function-1.expect.md

@@ -23,19 +23,27 @@ export const FIXTURE_ENTRYPOINT = {
 ```javascript
 import { c as _c } from "react/compiler-runtime";
 function component(a) {
-  const $ = _c(2);
+  const $ = _c(4);
   let t0;
   if ($[0] !== a) {
-    const z = { a };
-    t0 = function () {
-      console.log(z);
-    };
+    t0 = { a };
     $[0] = a;
     $[1] = t0;
   } else {
     t0 = $[1];
   }
-  const x = t0;
+  const z = t0;
+  let t1;
+  if ($[2] !== z) {
+    t1 = function () {
+      console.log(z);
+    };
+    $[2] = z;
+    $[3] = t1;
+  } else {
+    t1 = $[3];
+  }
+  const x = t1;
   return x;
 }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/capturing-function-runs-inference.expect.md

@@ -22,19 +22,35 @@ export const FIXTURE_ENTRYPOINT = {
 import { c as _c } from "react/compiler-runtime";
 import { Stringify } from "shared-runtime";
 function Component(t0) {
-  const $ = _c(2);
+  const $ = _c(6);
   const { a } = t0;
   let t1;
   if ($[0] !== a) {
-    const z = { a };
-    const p = () => <Stringify>{z}</Stringify>;
-    t1 = p();
+    t1 = { a };
     $[0] = a;
     $[1] = t1;
   } else {
     t1 = $[1];
   }
-  return t1;
+  const z = t1;
+  let t2;
+  if ($[2] !== z) {
+    t2 = () => <Stringify>{z}</Stringify>;
+    $[2] = z;
+    $[3] = t2;
+  } else {
+    t2 = $[3];
+  }
+  const p = t2;
+  let t3;
+  if ($[4] !== p) {
+    t3 = p();
+    $[4] = p;
+    $[5] = t3;
+  } else {
+    t3 = $[5];
+  }
+  return t3;
 }
 
 export const FIXTURE_ENTRYPOINT = {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/capturing-variable-in-nested-block.expect.md

@@ -25,19 +25,27 @@ export const FIXTURE_ENTRYPOINT = {
 ```javascript
 import { c as _c } from "react/compiler-runtime";
 function component(a) {
-  const $ = _c(2);
+  const $ = _c(4);
   let t0;
   if ($[0] !== a) {
-    const z = { a };
-    t0 = function () {
-      console.log(z);
-    };
+    t0 = { a };
     $[0] = a;
     $[1] = t0;
   } else {
     t0 = $[1];
   }
-  const x = t0;
+  const z = t0;
+  let t1;
+  if ($[2] !== z) {
+    t1 = function () {
+      console.log(z);
+    };
+    $[2] = z;
+    $[3] = t1;
+  } else {
+    t1 = $[3];
+  }
+  const x = t1;
   return x;
 }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/capturing-variable-in-nested-function.expect.md

@@ -25,21 +25,29 @@ export const FIXTURE_ENTRYPOINT = {
 ```javascript
 import { c as _c } from "react/compiler-runtime";
 function component(a) {
-  const $ = _c(2);
+  const $ = _c(4);
   let t0;
   if ($[0] !== a) {
-    const z = { a };
-    t0 = function () {
-      (function () {
-        console.log(z);
-      })();
-    };
+    t0 = { a };
     $[0] = a;
     $[1] = t0;
   } else {
     t0 = $[1];
   }
-  const x = t0;
+  const z = t0;
+  let t1;
+  if ($[2] !== z) {
+    t1 = function () {
+      (function () {
+        console.log(z);
+      })();
+    };
+    $[2] = z;
+    $[3] = t1;
+  } else {
+    t1 = $[3];
+  }
+  const x = t1;
   return x;
 }
 

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/ecma/error.reserved-words.expect.md

@@ -1,32 +0,0 @@
-
-## Input
-
-```javascript
-import {useRef} from 'react';
-
-function useThing(fn) {
-  const fnRef = useRef(fn);
-  const ref = useRef(null);
-
-  if (ref.current === null) {
-    ref.current = function (this: unknown, ...args) {
-      return fnRef.current.call(this, ...args);
-    };
-  }
-  return ref.current;
-}
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Error: Expected a non-reserved identifier name
-
-`this` is a reserved word in JavaScript and cannot be used as an identifier name.
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/ecma/error.reserved-words.ts

@@ -1,13 +0,0 @@
-import {useRef} from 'react';
-
-function useThing(fn) {
-  const fnRef = useRef(fn);
-  const ref = useRef(null);
-
-  if (ref.current === null) {
-    ref.current = function (this: unknown, ...args) {
-      return fnRef.current.call(this, ...args);
-    };
-  }
-  return ref.current;
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-infer-mutation-aliasing-effects.expect.md

@@ -1,46 +0,0 @@
-
-## Input
-
-```javascript
-import {useCallback, useRef} from 'react';
-
-export default function useThunkDispatch(state, dispatch, extraArg) {
-  const stateRef = useRef(state);
-  stateRef.current = state;
-
-  return useCallback(
-    function thunk(action) {
-      if (typeof action === 'function') {
-        return action(thunk, () => stateRef.current, extraArg);
-      } else {
-        dispatch(action);
-        return undefined;
-      }
-    },
-    [dispatch, extraArg]
-  );
-}
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Invariant: [InferMutationAliasingEffects] Expected value kind to be initialized
-
-<unknown> thunk$14.
-
-error.bug-infer-mutation-aliasing-effects.ts:10:22
-   8 |     function thunk(action) {
-   9 |       if (typeof action === 'function') {
-> 10 |         return action(thunk, () => stateRef.current, extraArg);
-     |                       ^^^^^ [InferMutationAliasingEffects] Expected value kind to be initialized
-  11 |       } else {
-  12 |         dispatch(action);
-  13 |         return undefined;
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-infer-mutation-aliasing-effects.js

@@ -1,18 +0,0 @@
-import {useCallback, useRef} from 'react';
-
-export default function useThunkDispatch(state, dispatch, extraArg) {
-  const stateRef = useRef(state);
-  stateRef.current = state;
-
-  return useCallback(
-    function thunk(action) {
-      if (typeof action === 'function') {
-        return action(thunk, () => stateRef.current, extraArg);
-      } else {
-        dispatch(action);
-        return undefined;
-      }
-    },
-    [dispatch, extraArg]
-  );
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-codegen-methodcall.expect.md

@@ -1,31 +0,0 @@
-
-## Input
-
-```javascript
-const YearsAndMonthsSince = () => {
-  const diff = foo();
-  const months = Math.floor(diff.bar());
-  return <>{months}</>;
-};
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Invariant: [Codegen] Internal error: MethodCall::property must be an unpromoted + unmemoized MemberExpression. Got a `Identifier`
-
-error.bug-invariant-codegen-methodcall.ts:3:17
-  1 | const YearsAndMonthsSince = () => {
-  2 |   const diff = foo();
-> 3 |   const months = Math.floor(diff.bar());
-    |                  ^^^^^^^^^^ [Codegen] Internal error: MethodCall::property must be an unpromoted + unmemoized MemberExpression. Got a `Identifier`
-  4 |   return <>{months}</>;
-  5 | };
-  6 |
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-codegen-methodcall.js

@@ -1,5 +0,0 @@
-const YearsAndMonthsSince = () => {
-  const diff = foo();
-  const months = Math.floor(diff.bar());
-  return <>{months}</>;
-};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-couldnt-find-binding-for-decl.expect.md

@@ -1,37 +0,0 @@
-
-## Input
-
-```javascript
-import {useEffect} from 'react';
-
-export function Foo() {
-  useEffect(() => {
-    try {
-      // do something
-    } catch ({status}) {
-      // do something
-    }
-  }, []);
-}
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Invariant: (BuildHIR::lowerAssignment) Could not find binding for declaration.
-
-error.bug-invariant-couldnt-find-binding-for-decl.ts:7:14
-   5 |     try {
-   6 |       // do something
->  7 |     } catch ({status}) {
-     |               ^^^^^^ (BuildHIR::lowerAssignment) Could not find binding for declaration.
-   8 |       // do something
-   9 |     }
-  10 |   }, []);
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-couldnt-find-binding-for-decl.js

@@ -1,11 +0,0 @@
-import {useEffect} from 'react';
-
-export function Foo() {
-  useEffect(() => {
-    try {
-      // do something
-    } catch ({status}) {
-      // do something
-    }
-  }, []);
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-expected-break-target.expect.md

@@ -1,32 +0,0 @@
-
-## Input
-
-```javascript
-import {useMemo} from 'react';
-
-export default function useFoo(text) {
-  return useMemo(() => {
-    try {
-      let formattedText = '';
-      try {
-        formattedText = format(text);
-      } catch {
-        console.log('error');
-      }
-      return formattedText || '';
-    } catch (e) {}
-  }, [text]);
-}
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Invariant: Expected a break target
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-expected-break-target.js

@@ -1,15 +0,0 @@
-import {useMemo} from 'react';
-
-export default function useFoo(text) {
-  return useMemo(() => {
-    try {
-      let formattedText = '';
-      try {
-        formattedText = format(text);
-      } catch {
-        console.log('error');
-      }
-      return formattedText || '';
-    } catch (e) {}
-  }, [text]);
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-expected-consistent-destructuring.expect.md

@@ -1,44 +0,0 @@
-
-## Input
-
-```javascript
-import {useMemo} from 'react';
-import {useFoo, formatB, Baz} from './lib';
-
-export const Example = ({data}) => {
-  let a;
-  let b;
-
-  if (data) {
-    ({a, b} = data);
-  }
-
-  const foo = useFoo(a);
-  const bar = useMemo(() => formatB(b), [b]);
-
-  return <Baz foo={foo} bar={bar} />;
-};
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Invariant: Expected consistent kind for destructuring
-
-Other places were `Reassign` but 'mutate? #t8$46[7:9]{reactive}' is const.
-
-error.bug-invariant-expected-consistent-destructuring.ts:9:9
-   7 |
-   8 |   if (data) {
->  9 |     ({a, b} = data);
-     |          ^ Expected consistent kind for destructuring
-  10 |   }
-  11 |
-  12 |   const foo = useFoo(a);
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-expected-consistent-destructuring.js

@@ -1,16 +0,0 @@
-import {useMemo} from 'react';
-import {useFoo, formatB, Baz} from './lib';
-
-export const Example = ({data}) => {
-  let a;
-  let b;
-
-  if (data) {
-    ({a, b} = data);
-  }
-
-  const foo = useFoo(a);
-  const bar = useMemo(() => formatB(b), [b]);
-
-  return <Baz foo={foo} bar={bar} />;
-};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-local-or-context-references.expect.md

@@ -1,46 +0,0 @@
-
-## Input
-
-```javascript
-import {useState} from 'react';
-import {bar} from './bar';
-
-export const useFoot = () => {
-  const [, setState] = useState(null);
-  try {
-    const {data} = bar();
-    setState({
-      data,
-      error: null,
-    });
-  } catch (err) {
-    setState(_prevState => ({
-      loading: false,
-      error: err,
-    }));
-  }
-};
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Invariant: Expected all references to a variable to be consistently local or context references
-
-Identifier <unknown> err$7 is referenced as a context variable, but was previously referenced as a [object Object] variable.
-
-error.bug-invariant-local-or-context-references.ts:15:13
-  13 |     setState(_prevState => ({
-  14 |       loading: false,
-> 15 |       error: err,
-     |              ^^^ Expected all references to a variable to be consistently local or context references
-  16 |     }));
-  17 |   }
-  18 | };
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-local-or-context-references.js

@@ -1,18 +0,0 @@
-import {useState} from 'react';
-import {bar} from './bar';
-
-export const useFoot = () => {
-  const [, setState] = useState(null);
-  try {
-    const {data} = bar();
-    setState({
-      data,
-      error: null,
-    });
-  } catch (err) {
-    setState(_prevState => ({
-      loading: false,
-      error: err,
-    }));
-  }
-};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-unexpected-terminal-in-optional.expect.md

@@ -1,34 +0,0 @@
-
-## Input
-
-```javascript
-const Foo = ({json}) => {
-  try {
-    const foo = JSON.parse(json)?.foo;
-    return <span>{foo}</span>;
-  } catch {
-    return null;
-  }
-};
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Invariant: Unexpected terminal in optional
-
-error.bug-invariant-unexpected-terminal-in-optional.ts:3:16
-  1 | const Foo = ({json}) => {
-  2 |   try {
-> 3 |     const foo = JSON.parse(json)?.foo;
-    |                 ^^^^ Unexpected terminal in optional
-  4 |     return <span>{foo}</span>;
-  5 |   } catch {
-  6 |     return null;
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-unexpected-terminal-in-optional.js

@@ -1,8 +0,0 @@
-const Foo = ({json}) => {
-  try {
-    const foo = JSON.parse(json)?.foo;
-    return <span>{foo}</span>;
-  } catch {
-    return null;
-  }
-};

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-unnamed-temporary.expect.md

@@ -1,30 +0,0 @@
-
-## Input
-
-```javascript
-import Bar from './Bar';
-
-export function Foo() {
-  return (
-    <Bar
-      renderer={(...props) => {
-        return <span {...props}>{displayValue}</span>;
-      }}
-    />
-  );
-}
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Invariant: Expected temporaries to be promoted to named identifiers in an earlier pass
-
-identifier 15 is unnamed.
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.bug-invariant-unnamed-temporary.js

@@ -1,11 +0,0 @@
-import Bar from './Bar';
-
-export function Foo() {
-  return (
-    <Bar
-      renderer={(...props) => {
-        return <span {...props}>{displayValue}</span>;
-      }}
-    />
-  );
-}

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

@@ -32,30 +32,48 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-Found 2 errors:
+Found 4 errors:
 
-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: This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.capture-ref-for-mutation.ts:12:13
   10 |   };
   11 |   const moveLeft = {
 > 12 |     handler: handleKey('left')(),
-     |              ^^^^^^^^^^^^^^^^^ This function accesses a ref value
+     |              ^^^^^^^^^^^^^^^^^ This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef)
   13 |   };
   14 |   const moveRight = {
   15 |     handler: handleKey('right')(),
 
-Error: Cannot access refs during render
+Error: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
-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.capture-ref-for-mutation.ts:12:13
+  10 |   };
+  11 |   const moveLeft = {
+> 12 |     handler: handleKey('left')(),
+     |              ^^^^^^^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
+  13 |   };
+  14 |   const moveRight = {
+  15 |     handler: handleKey('right')(),
+
+Error: This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.capture-ref-for-mutation.ts:15:13
   13 |   };
   14 |   const moveRight = {
 > 15 |     handler: handleKey('right')(),
-     |              ^^^^^^^^^^^^^^^^^^ This function accesses a ref value
+     |              ^^^^^^^^^^^^^^^^^^ This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef)
+  16 |   };
+  17 |   return [moveLeft, moveRight];
+  18 | }
+
+Error: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
+
+error.capture-ref-for-mutation.ts:15:13
+  13 |   };
+  14 |   const moveRight = {
+> 15 |     handler: handleKey('right')(),
+     |              ^^^^^^^^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   16 |   };
   17 |   return [moveLeft, moveRight];
   18 | }

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

@@ -22,28 +22,24 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 2 errors:
 
-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: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.hook-ref-value.ts:5:23
   3 | function Component(props) {
   4 |   const ref = useRef();
 > 5 |   useEffect(() => {}, [ref.current]);
-    |                        ^^^^^^^^^^^ Cannot access ref value during render
+    |                        ^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   6 | }
   7 |
   8 | export const FIXTURE_ENTRYPOINT = {
 
-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: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.hook-ref-value.ts:5:23
   3 | function Component(props) {
   4 |   const ref = useRef();
 > 5 |   useEffect(() => {}, [ref.current]);
-    |                        ^^^^^^^^^^^ Cannot access ref value during render
+    |                        ^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   6 | }
   7 |
   8 | export const FIXTURE_ENTRYPOINT = {

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

@@ -17,15 +17,13 @@ function Component(props) {
 ```
 Found 1 error:
 
-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: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.invalid-access-ref-during-render.ts:4:16
   2 | function Component(props) {
   3 |   const ref = useRef(null);
 > 4 |   const value = ref.current;
-    |                 ^^^^^^^^^^^ Cannot access ref value during render
+    |                 ^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   5 |   return value;
   6 | }
   7 |

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

@@ -1,45 +0,0 @@
-
-## Input
-
-```javascript
-import {useReducer, useRef} from 'react';
-
-function Component(props) {
-  const ref = useRef(props.value);
-  const [state] = useReducer(
-    (state, action) => state + action,
-    0,
-    init => ref.current
-  );
-
-  return <Stringify state={state} />;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-};
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-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-reducer-init.ts:8:4
-   6 |     (state, action) => state + action,
-   7 |     0,
->  8 |     init => ref.current
-     |     ^^^^^^^^^^^^^^^^^^^ 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-init.js

@@ -1,17 +0,0 @@
-import {useReducer, useRef} from 'react';
-
-function Component(props) {
-  const ref = useRef(props.value);
-  const [state] = useReducer(
-    (state, action) => state + action,
-    0,
-    init => ref.current
-  );
-
-  return <Stringify state={state} />;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-};

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

@@ -1,41 +0,0 @@
-
-## Input
-
-```javascript
-import {useReducer, useRef} from 'react';
-
-function Component(props) {
-  const ref = useRef(props.value);
-  const [state] = useReducer(() => ref.current, null);
-
-  return <Stringify state={state} />;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-};
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-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-reducer.ts:5:29
-  3 | function Component(props) {
-  4 |   const ref = useRef(props.value);
-> 5 |   const [state] = useReducer(() => ref.current, null);
-    |                              ^^^^^^^^^^^^^^^^^ 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-reducer.js

@@ -1,13 +0,0 @@
-import {useReducer, useRef} from 'react';
-
-function Component(props) {
-  const ref = useRef(props.value);
-  const [state] = useReducer(() => ref.current, null);
-
-  return <Stringify state={state} />;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-};

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

@@ -1,37 +0,0 @@
-
-## Input
-
-```javascript
-import {useRef} from 'react';
-
-function Component() {
-  const ref = useRef(null);
-  const object = {};
-  object.foo = () => ref.current;
-  const refValue = object.foo();
-  return <div>{refValue}</div>;
-}
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-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:7:19
-   5 |   const object = {};
-   6 |   object.foo = () => ref.current;
->  7 |   const refValue = object.foo();
-     |                    ^^^^^^^^^^ This function accesses a ref value
-   8 |   return <div>{refValue}</div>;
-   9 | }
-  10 |
-```
-          
-      

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

@@ -1,9 +0,0 @@
-import {useRef} from 'react';
-
-function Component() {
-  const ref = useRef(null);
-  const object = {};
-  object.foo = () => ref.current;
-  const refValue = object.foo();
-  return <div>{refValue}</div>;
-}

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

@@ -1,41 +0,0 @@
-
-## Input
-
-```javascript
-import {useRef, useState} from 'react';
-
-function Component(props) {
-  const ref = useRef(props.value);
-  const [state] = useState(() => ref.current);
-
-  return <Stringify state={state} />;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-};
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-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-state-initializer.ts:5:27
-  3 | function Component(props) {
-  4 |   const ref = useRef(props.value);
-> 5 |   const [state] = useState(() => ref.current);
-    |                            ^^^^^^^^^^^^^^^^^ 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-state-initializer.js

@@ -1,13 +0,0 @@
-import {useRef, useState} from 'react';
-
-function Component(props) {
-  const ref = useRef(props.value);
-  const [state] = useState(() => ref.current);
-
-  return <Stringify state={state} />;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{value: 42}],
-};

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

@@ -21,15 +21,13 @@ function Component(props) {
 ```
 Found 1 error:
 
-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: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.invalid-aliased-ref-in-callback-invoked-during-render-.ts:9:33
    7 |     return <Foo item={item} current={current} />;
    8 |   };
 >  9 |   return <Items>{props.items.map(item => renderItem(item))}</Items>;
-     |                                  ^^^^^^^^^^^^^^^^^^^^^^^^ Cannot access ref value during render
+     |                                  ^^^^^^^^^^^^^^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   10 | }
   11 |
 ```

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

@@ -1,36 +0,0 @@
-
-## Input
-
-```javascript
-// @flow @enableTreatRefLikeIdentifiersAsRefs @validateRefAccessDuringRender
-import {makeObject_Primitives} from 'shared-runtime';
-
-component Example() {
-  const fooRef = makeObject_Primitives();
-  fooRef.current = true;
-
-  return <Stringify foo={fooRef} />;
-}
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-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)
-
-  4 | component Example() {
-  5 |   const fooRef = makeObject_Primitives();
-> 6 |   fooRef.current = true;
-    |   ^^^^^^^^^^^^^^ Cannot update ref during render
-  7 |
-  8 |   return <Stringify foo={fooRef} />;
-  9 | }
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-assign-current-inferred-ref-during-render.js

@@ -1,9 +0,0 @@
-// @flow @enableTreatRefLikeIdentifiersAsRefs @validateRefAccessDuringRender
-import {makeObject_Primitives} from 'shared-runtime';
-
-component Example() {
-  const fooRef = makeObject_Primitives();
-  fooRef.current = true;
-
-  return <Stringify foo={fooRef} />;
-}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-assing-to-ref-current-in-render.expect.md

@@ -1,36 +0,0 @@
-
-## Input
-
-```javascript
-// @flow
-
-component Foo() {
-  const foo = useFoo();
-  foo.current = true;
-  return <div />;
-}
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Error: This value cannot be modified
-
-Modifying a value returned from a hook is not allowed. Consider moving the modification into the hook where the value is constructed.
-
-  3 | component Foo() {
-  4 |   const foo = useFoo();
-> 5 |   foo.current = true;
-    |   ^^^ value cannot be modified
-  6 |   return <div />;
-  7 | }
-  8 |
-
-Hint: If this value is a Ref (value returned by `useRef()`), rename the variable to end in "Ref".
-```
-          
-      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-assing-to-ref-current-in-render.js

@@ -1,7 +0,0 @@
-// @flow
-
-component Foo() {
-  const foo = useFoo();
-  foo.current = true;
-  return <div />;
-}

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

@@ -1,39 +0,0 @@
-
-## Input
-
-```javascript
-// @validateNoDerivedComputationsInEffects
-function BadExample() {
-  const [firstName, setFirstName] = useState('Taylor');
-  const [lastName, setLastName] = useState('Swift');
-
-  // 🔴 Avoid: redundant state and unnecessary Effect
-  const [fullName, setFullName] = useState('');
-  useEffect(() => {
-    setFullName(capitalize(firstName + ' ' + lastName));
-  }, [firstName, lastName]);
-
-  return <div>{fullName}</div>;
-}
-
-```
-
-
-## Error
-
-```
-Found 1 error:
-
-Error: Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
-
-error.invalid-derived-computation-in-effect.ts:9:4
-   7 |   const [fullName, setFullName] = useState('');
-   8 |   useEffect(() => {
->  9 |     setFullName(capitalize(firstName + ' ' + lastName));
-     |     ^^^^^^^^^^^ Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
-  10 |   }, [firstName, lastName]);
-  11 |
-  12 |   return <div>{fullName}</div>;
-```
-          
-      

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

@@ -1,13 +0,0 @@
-// @validateNoDerivedComputationsInEffects
-function BadExample() {
-  const [firstName, setFirstName] = useState('Taylor');
-  const [lastName, setLastName] = useState('Swift');
-
-  // 🔴 Avoid: redundant state and unnecessary Effect
-  const [fullName, setFullName] = useState('');
-  useEffect(() => {
-    setFullName(capitalize(firstName + ' ' + lastName));
-  }, [firstName, lastName]);
-
-  return <div>{fullName}</div>;
-}

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

@@ -18,15 +18,13 @@ function Component() {
 ```
 Found 1 error:
 
-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: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.invalid-disallow-mutating-ref-in-render.ts:4:2
   2 | function Component() {
   3 |   const ref = useRef(null);
 > 4 |   ref.current = false;
-    |   ^^^^^^^^^^^ Cannot update ref during render
+    |   ^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   5 |
   6 |   return <button ref={ref} />;
   7 | }

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

@@ -21,17 +21,26 @@ function Component() {
 ## Error
 
 ```
-Found 1 error:
+Found 2 errors:
 
-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: This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.invalid-disallow-mutating-refs-in-render-transitive.ts:9:2
    7 |   };
    8 |   const changeRef = setRef;
 >  9 |   changeRef();
-     |   ^^^^^^^^^ This function accesses a ref value
+     |   ^^^^^^^^^ This function accesses a ref value (the `current` property), which may not be accessed during render. (https://react.dev/reference/react/useRef)
+  10 |
+  11 |   return <button ref={ref} />;
+  12 | }
+
+Error: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
+
+error.invalid-disallow-mutating-refs-in-render-transitive.ts:9:2
+   7 |   };
+   8 |   const changeRef = setRef;
+>  9 |   changeRef();
+     |   ^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   10 |
   11 |   return <button ref={ref} />;
   12 | }

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-pass-ref-to-function.expect.md

@@ -17,15 +17,13 @@ function Component(props) {
 ```
 Found 1 error:
 
-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: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.invalid-pass-ref-to-function.ts:4:16
   2 | function Component(props) {
   3 |   const ref = useRef(null);
 > 4 |   const x = foo(ref);
-    |                 ^^^ Passing a ref to a function may read its value during render
+    |                 ^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   5 |   return x.current;
   6 | }
   7 |

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-read-ref-prop-in-render-destructure.expect.md

@@ -16,15 +16,13 @@ function Component({ref}) {
 ```
 Found 1 error:
 
-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: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.invalid-read-ref-prop-in-render-destructure.ts:3:16
   1 | // @validateRefAccessDuringRender @compilationMode:"infer"
   2 | function Component({ref}) {
 > 3 |   const value = ref.current;
-    |                 ^^^^^^^^^^^ Cannot access ref value during render
+    |                 ^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   4 |   return <div>{value}</div>;
   5 | }
   6 |

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-read-ref-prop-in-render-property-load.expect.md

@@ -16,15 +16,13 @@ function Component(props) {
 ```
 Found 1 error:
 
-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: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.invalid-read-ref-prop-in-render-property-load.ts:3:16
   1 | // @validateRefAccessDuringRender @compilationMode:"infer"
   2 | function Component(props) {
 > 3 |   const value = props.ref.current;
-    |                 ^^^^^^^^^^^^^^^^^ Cannot access ref value during render
+    |                 ^^^^^^^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   4 |   return <div>{value}</div>;
   5 | }
   6 |

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

@@ -20,15 +20,13 @@ function Component(props) {
 ```
 Found 1 error:
 
-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: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.invalid-ref-in-callback-invoked-during-render.ts:8:33
    6 |     return <Foo item={item} current={current} />;
    7 |   };
 >  8 |   return <Items>{props.items.map(item => renderItem(item))}</Items>;
-     |                                  ^^^^^^^^^^^^^^^^^^^^^^^^ Cannot access ref value during render
+     |                                  ^^^^^^^^^^^^^^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
    9 | }
   10 |
 ```

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

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

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

@@ -17,28 +17,24 @@ function Component(props) {
 ```
 Found 2 errors:
 
-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: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.invalid-set-and-read-ref-during-render.ts:4:2
   2 | function Component(props) {
   3 |   const ref = useRef(null);
 > 4 |   ref.current = props.value;
-    |   ^^^^^^^^^^^ Cannot update ref during render
+    |   ^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   5 |   return ref.current;
   6 | }
   7 |
 
-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: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.invalid-set-and-read-ref-during-render.ts:5:9
   3 |   const ref = useRef(null);
   4 |   ref.current = props.value;
 > 5 |   return ref.current;
-    |          ^^^^^^^^^^^ Cannot access ref value during render
+    |          ^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   6 | }
   7 |
 ```

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-set-and-read-ref-nested-property-during-render.expect.md

@@ -17,28 +17,24 @@ function Component(props) {
 ```
 Found 2 errors:
 
-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: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.invalid-set-and-read-ref-nested-property-during-render.ts:4:2
   2 | function Component(props) {
   3 |   const ref = useRef({inner: null});
 > 4 |   ref.current.inner = props.value;
-    |   ^^^^^^^^^^^ Cannot update ref during render
+    |   ^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   5 |   return ref.current.inner;
   6 | }
   7 |
 
-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: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
 
 error.invalid-set-and-read-ref-nested-property-during-render.ts:5:9
   3 |   const ref = useRef({inner: null});
   4 |   ref.current.inner = props.value;
 > 5 |   return ref.current.inner;
-    |          ^^^^^^^^^^^^^^^^^ Cannot access ref value during render
+    |          ^^^^^^^^^^^^^^^^^ Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef)
   6 | }
   7 |
 ```