[flow] Upgrade from 0.281 -> 0.282

Add suppression for React\$Element incompatibility with ReactNodeList in
  ReactDOMRootFB.js render function. Flow 0.282 has stricter type checking
  for the React\$Node union type.

compiler/apps/playground/package.json

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

compiler/apps/playground/yarn.lock

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

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

@@ -279,20 +279,17 @@ function runWithEnvironment(
       validateNoSetStateInRender(hir).unwrap();
     }
 
-    if (
-      env.config.validateNoDerivedComputationsInEffects_exp &&
-      env.outputMode === 'lint'
-    ) {
+    if (env.config.validateNoDerivedComputationsInEffects_exp) {
       env.logErrors(validateNoDerivedComputationsInEffects_exp(hir));
     } else if (env.config.validateNoDerivedComputationsInEffects) {
       validateNoDerivedComputationsInEffects(hir);
     }
 
-    if (env.config.validateNoSetStateInEffects && env.outputMode === 'lint') {
+    if (env.config.validateNoSetStateInEffects) {
       env.logErrors(validateNoSetStateInEffects(hir, env));
     }
 
-    if (env.config.validateNoJSXInTryStatements && env.outputMode === 'lint') {
+    if (env.config.validateNoJSXInTryStatements) {
       env.logErrors(validateNoJSXInTryStatement(hir));
     }
 
@@ -323,11 +320,7 @@ function runWithEnvironment(
     value: hir,
   });
 
-  if (
-    env.enableValidations &&
-    env.config.validateStaticComponents &&
-    env.outputMode === 'lint'
-  ) {
+  if (env.enableValidations && env.config.validateStaticComponents) {
     env.logErrors(validateStaticComponents(hir));
   }
 

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

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

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

@@ -39,7 +39,6 @@ import {TypeConfig} from './TypeSchema';
  * The React team is open to collaborating with library authors to help develop compatible versions of these APIs,
  * and we have already reached out to the teams who own any API listed here to ensure they are aware of the issue.
  */
-
 export function defaultModuleTypeProvider(
   moduleName: string,
 ): TypeConfig | null {

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

@@ -41,7 +41,6 @@ import {
 } from './HIR';
 import {
   BuiltInMixedReadonlyId,
-  BuiltInUseFragmentId,
   DefaultMutatingHook,
   DefaultNonmutatingHook,
   FunctionSignature,
@@ -649,12 +648,6 @@ export const EnvironmentConfigSchema = z.object({
    */
   enableTreatSetIdentifiersAsStateSetters: z.boolean().default(false),
 
-  /**
-   * Treat hook calls named "useFragment" as returning BuiltInUseFragment type.
-   * This enables tracking of Relay fragment-derived values through the program.
-   */
-  enableTreatUseFragmentAsRelay: z.boolean().default(false),
-
   /*
    * If specified a value, the compiler lowers any calls to `useContext` to use
    * this value as the callee.
@@ -826,22 +819,14 @@ export class Environment {
         ],
         suggestions: null,
       });
-      // Use BuiltInUseFragmentId for useFragment to enable tracking of fragment-derived values
-      const returnTypeShapeId =
-        hookName === 'useFragment'
-          ? BuiltInUseFragmentId
-          : hook.transitiveMixedData
-            ? BuiltInMixedReadonlyId
-            : null;
       this.#globals.set(
         hookName,
         addHook(this.#shapes, {
           positionalParams: [],
           restParam: hook.effectKind,
-          returnType:
-            returnTypeShapeId != null
-              ? {kind: 'Object', shapeId: returnTypeShapeId}
-              : {kind: 'Poly'},
+          returnType: hook.transitiveMixedData
+            ? {kind: 'Object', shapeId: BuiltInMixedReadonlyId}
+            : {kind: 'Poly'},
           returnValueKind: hook.valueKind,
           calleeEffect: Effect.Read,
           hookKind: 'Custom',

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

@@ -694,13 +694,11 @@ export type SpreadPattern = {
 export type ArrayPattern = {
   kind: 'ArrayPattern';
   items: Array<Place | SpreadPattern | Hole>;
-  loc: SourceLocation;
 };
 
 export type ObjectPattern = {
   kind: 'ObjectPattern';
   properties: Array<ObjectProperty | SpreadPattern>;
-  loc: SourceLocation;
 };
 
 export type ObjectPropertyKey =
@@ -1886,10 +1884,6 @@ export function isUseStateType(id: Identifier): boolean {
   return id.type.kind === 'Object' && id.type.shapeId === 'BuiltInUseState';
 }
 
-export function isUseFragmentType(id: Identifier): boolean {
-  return id.type.kind === 'Object' && id.type.shapeId === 'BuiltInUseFragment';
-}
-
 export function isJsxType(type: Type): boolean {
   return type.kind === 'Object' && type.shapeId === 'BuiltInJsx';
 }

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

@@ -392,7 +392,6 @@ export const BuiltInSetActionStateId = 'BuiltInSetActionState';
 export const BuiltInUseRefId = 'BuiltInUseRefId';
 export const BuiltInRefValueId = 'BuiltInRefValue';
 export const BuiltInMixedReadonlyId = 'BuiltInMixedReadonly';
-export const BuiltInUseFragmentId = 'BuiltInUseFragment';
 export const BuiltInUseEffectHookId = 'BuiltInUseEffectHook';
 export const BuiltInUseLayoutEffectHookId = 'BuiltInUseLayoutEffectHook';
 export const BuiltInUseInsertionEffectHookId = 'BuiltInUseInsertionEffectHook';
@@ -1476,16 +1475,6 @@ addObject(BUILTIN_SHAPES, BuiltInMixedReadonlyId, [
   ['*', {kind: 'Object', shapeId: BuiltInMixedReadonlyId}],
 ]);
 
-/**
- * BuiltInUseFragment represents values returned from Relay's useFragment hook.
- * The catch-all property ensures that property accesses on useFragment data
- * are also typed as BuiltInUseFragmentId, enabling tracking of fragment-derived
- * values through the program.
- */
-addObject(BUILTIN_SHAPES, BuiltInUseFragmentId, [
-  ['*', {kind: 'Object', shapeId: BuiltInUseFragmentId}],
-]);
-
 addObject(BUILTIN_SHAPES, BuiltInJsxId, []);
 addObject(BUILTIN_SHAPES, BuiltInFunctionId, []);
 

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

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

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

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

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

@@ -33,7 +33,6 @@ import {
   BuiltInPropsId,
   BuiltInRefValueId,
   BuiltInSetStateId,
-  BuiltInUseFragmentId,
   BuiltInUseRefId,
 } from '../HIR/ObjectShape';
 import {eachInstructionLValue, eachInstructionOperand} from '../HIR/visitors';
@@ -266,18 +265,7 @@ function* generateInstructionTypes(
 
     case 'LoadGlobal': {
       const globalType = env.getGlobalDeclaration(value.binding, value.loc);
-      // If the binding is useFragment and the flag is enabled, override the type
-      if (
-        env.config.enableTreatUseFragmentAsRelay &&
-        value.binding.name === 'useFragment'
-      ) {
-        yield equation(left, {
-          kind: 'Function',
-          shapeId: BuiltInUseFragmentId,
-          return: {kind: 'Object', shapeId: BuiltInUseFragmentId},
-          isConstructor: false,
-        });
-      } else if (globalType) {
+      if (globalType) {
         yield equation(left, globalType);
       }
       break;
@@ -291,9 +279,9 @@ function* generateInstructionTypes(
        * (see https://github.com/facebook/react-forget/pull/1427)
        */
       let shapeId: string | null = null;
-      const calleeName = getName(names, value.callee.identifier.id);
       if (env.config.enableTreatSetIdentifiersAsStateSetters) {
-        if (calleeName.startsWith('set')) {
+        const name = getName(names, value.callee.identifier.id);
+        if (name.startsWith('set')) {
           shapeId = BuiltInSetStateId;
         }
       }
@@ -742,32 +730,26 @@ class Unifier {
          *   T2
          *   Phi [
          *     T3
-         *     Phi [T4]
+         *     Phi [
+         *       T4
+         *     ]
          *   ]
          * ]
          *
-         * Which then resolves to T1, T2, T3, T4 as candidates (because
-         * they're all resolved Phi types).
+         * Which avoids the cycle
          */
-        const operands: Array<Type> = [];
+        const operands = [];
         for (const operand of type.operands) {
-          if (typeEquals(operand, v)) {
+          if (operand.kind === 'Type' && operand.id === v.id) {
             continue;
           }
-          const resolved = this.tryResolveType(v, this.get(operand));
+          const resolved = this.tryResolveType(v, operand);
           if (resolved === null) {
             return null;
           }
           operands.push(resolved);
         }
-        if (operands.length === 0) {
-          // All operands were `v`
-          return null;
-        }
-        return {
-          kind: 'Phi',
-          operands,
-        };
+        return {kind: 'Phi', operands};
       }
       case 'Type': {
         const substitution = this.get(type);
@@ -877,19 +859,12 @@ function tryUnionTypes(ty1: Type, ty2: Type): Type | null {
   } else if (ty2.kind === 'Object' && ty2.shapeId === BuiltInMixedReadonlyId) {
     readonlyType = ty2;
     otherType = ty1;
-  } else if (ty1.kind === 'Object' && ty1.shapeId === BuiltInUseFragmentId) {
-    readonlyType = ty1;
-    otherType = ty2;
-  } else if (ty2.kind === 'Object' && ty2.shapeId === BuiltInUseFragmentId) {
-    readonlyType = ty2;
-    otherType = ty1;
   } else {
     return null;
   }
   if (otherType.kind === 'Primitive') {
     /**
      * Union(Primitive | MixedReadonly) = MixedReadonly
-     * Union(Primitive | UseFragment) = UseFragment
      *
      * For example, `data ?? null` could return `data`, the fact that RHS
      * is a primitive doesn't guarantee the result is a primitive.
@@ -901,7 +876,6 @@ function tryUnionTypes(ty1: Type, ty2: Type): Type | null {
   ) {
     /**
      * Union(Array | MixedReadonly) = Array
-     * Union(Array | UseFragment) = Array
      *
      * In practice this pattern means the result is always an array. Given
      * that this behavior requires opting-in to the mixedreadonly type

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

@@ -15,7 +15,6 @@ import {
   IdentifierId,
   isSetStateType,
   isUseEffectHookType,
-  isUseFragmentType,
   Place,
   CallExpression,
   Instruction,
@@ -28,14 +27,8 @@ import {
 import {eachInstructionLValue, eachInstructionOperand} from '../HIR/visitors';
 import {isMutable} from '../ReactiveScopes/InferReactiveScopeVariables';
 import {assertExhaustive} from '../Utils/utils';
-import {printInstruction} from '../HIR/PrintHIR';
 
-type TypeOfValue =
-  | 'ignored'
-  | 'fromProps'
-  | 'fromState'
-  | 'fromPropsAndState'
-  | 'fromRelay';
+type TypeOfValue = 'ignored' | 'fromProps' | 'fromState' | 'fromPropsAndState';
 
 type DerivationMetadata = {
   typeOfValue: TypeOfValue;
@@ -306,9 +299,6 @@ function joinValue(
   if (lvalueType === 'ignored') return valueType;
   if (valueType === 'ignored') return lvalueType;
   if (lvalueType === valueType) return lvalueType;
-  if (lvalueType === 'fromRelay' || valueType === 'fromRelay') {
-    return 'fromRelay';
-  }
   return 'fromPropsAndState';
 }
 
@@ -407,15 +397,6 @@ function recordInstructionDerivations(
         true,
       );
       return;
-    } else if (isUseFragmentType(lvalue.identifier)) {
-      typeOfValue = 'fromRelay';
-      context.derivationCache.addDerivationEntry(
-        lvalue,
-        new Set(),
-        typeOfValue,
-        true,
-      );
-      return;
     }
   } else if (value.kind === 'ArrayExpression') {
     context.candidateDependencies.set(lvalue.identifier.id, value);
@@ -530,13 +511,6 @@ type TreeNode = {
   children: Array<TreeNode>;
 };
 
-type DataFlowInfo = {
-  rootSources: string;
-  trees: Array<string>;
-  propsArr: Array<string>;
-  stateArr: Array<string>;
-};
-
 function buildTreeNode(
   sourceId: IdentifierId,
   context: ValidationContext,
@@ -654,51 +628,6 @@ function renderTree(
   return result;
 }
 
-/**
- * Builds the data flow information including trees and source categorization
- */
-function buildDataFlowInfo(
-  sourceIds: Set<IdentifierId>,
-  context: ValidationContext,
-): DataFlowInfo {
-  const propsSet = new Set<string>();
-  const stateSet = new Set<string>();
-
-  const rootNodesMap = new Map<string, TreeNode>();
-  for (const id of sourceIds) {
-    const nodes = buildTreeNode(id, context);
-    for (const node of nodes) {
-      if (!rootNodesMap.has(node.name)) {
-        rootNodesMap.set(node.name, node);
-      }
-    }
-  }
-  const rootNodes = Array.from(rootNodesMap.values());
-
-  const trees = rootNodes.map((node, index) =>
-    renderTree(node, '', index === rootNodes.length - 1, propsSet, stateSet),
-  );
-
-  const propsArr = Array.from(propsSet);
-  const stateArr = Array.from(stateSet);
-
-  let rootSources = '';
-  if (propsArr.length > 0) {
-    rootSources += `Props: [${propsArr.join(', ')}]`;
-  }
-  if (stateArr.length > 0) {
-    if (rootSources) rootSources += '\n';
-    rootSources += `State: [${stateArr.join(', ')}]`;
-  }
-
-  return {
-    rootSources,
-    trees,
-    propsArr,
-    stateArr,
-  };
-}
-
 function getFnLocalDeps(
   fn: FunctionExpression | undefined,
 ): Set<IdentifierId> | undefined {
@@ -815,26 +744,6 @@ function validateEffect(
         );
 
         if (argMetadata !== undefined) {
-          // Check if the value being set is derived from useFragment (Relay)
-          if (argMetadata.typeOfValue === 'fromRelay') {
-            console.log('relay');
-            context.errors.pushDiagnostic(
-              CompilerDiagnostic.create({
-                description:
-                  'Deriving value from Relay store. Instead of holding it in a local state, use a client schema extension to store the value directly in the Relay store.',
-                category: ErrorCategory.EffectDerivationsOfState,
-                reason:
-                  'Avoid storing Relay data in React state. Use client schema extensions instead.',
-              }).withDetails({
-                kind: 'error',
-                loc: instr.value.callee.loc,
-                message:
-                  'setState with Relay-derived value. Use client schema instead.',
-              }),
-            );
-            continue;
-          }
-
           effectDerivedSetStateCalls.push({
             value: instr.value,
             id: instr.value.callee.identifier.id,
@@ -883,16 +792,47 @@ function validateEffect(
       effectSetStateUsages.get(rootSetStateCall)!.size ===
         context.setStateUsages.get(rootSetStateCall)!.size - 1
     ) {
+      const propsSet = new Set<string>();
+      const stateSet = new Set<string>();
+
+      const rootNodesMap = new Map<string, TreeNode>();
+      for (const id of derivedSetStateCall.sourceIds) {
+        const nodes = buildTreeNode(id, context);
+        for (const node of nodes) {
+          if (!rootNodesMap.has(node.name)) {
+            rootNodesMap.set(node.name, node);
+          }
+        }
+      }
+      const rootNodes = Array.from(rootNodesMap.values());
+
+      const trees = rootNodes.map((node, index) =>
+        renderTree(
+          node,
+          '',
+          index === rootNodes.length - 1,
+          propsSet,
+          stateSet,
+        ),
+      );
+
       for (const dep of derivedSetStateCall.sourceIds) {
         if (cleanUpFunctionDeps !== undefined && cleanUpFunctionDeps.has(dep)) {
           return;
         }
       }
 
-      const {rootSources, trees} = buildDataFlowInfo(
-        derivedSetStateCall.sourceIds,
-        context,
-      );
+      const propsArr = Array.from(propsSet);
+      const stateArr = Array.from(stateSet);
+
+      let rootSources = '';
+      if (propsArr.length > 0) {
+        rootSources += `Props: [${propsArr.join(', ')}]`;
+      }
+      if (stateArr.length > 0) {
+        if (rootSources) rootSources += '\n';
+        rootSources += `State: [${stateArr.join(', ')}]`;
+      }
 
       const description = `Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user
 
@@ -917,80 +857,6 @@ See: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-o
           message: 'This should be computed during render, not in an effect',
         }),
       );
-    } else if (
-      rootSetStateCall !== null &&
-      effectSetStateUsages.has(rootSetStateCall) &&
-      context.setStateUsages.has(rootSetStateCall) &&
-      effectSetStateUsages.get(rootSetStateCall)!.size <
-        context.setStateUsages.get(rootSetStateCall)!.size
-    ) {
-      for (const dep of derivedSetStateCall.sourceIds) {
-        if (cleanUpFunctionDeps !== undefined && cleanUpFunctionDeps.has(dep)) {
-          return;
-        }
-      }
-
-      const {rootSources, trees} = buildDataFlowInfo(
-        derivedSetStateCall.sourceIds,
-        context,
-      );
-
-      // Find setState calls outside the effect
-      const allSetStateUsages = context.setStateUsages.get(rootSetStateCall)!;
-      const effectUsages = effectSetStateUsages.get(rootSetStateCall)!;
-      const outsideEffectUsages: Array<SourceLocation> = [];
-
-      for (const usage of allSetStateUsages) {
-        if (!effectUsages.has(usage)) {
-          outsideEffectUsages.push(usage);
-        }
-      }
-
-      const description = `Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user
-
-This setState call is setting a derived value that depends on the following reactive sources:
-
-${rootSources}
-
-Data Flow Tree:
-${trees.join('\n')}
-
-This state is also being set outside of the effect. Consider hoisting the state up to a parent component and making this a controlled component.
-
-See: https://react.dev/learn/sharing-state-between-components`;
-
-      const diagnosticDetails: Array<{
-        kind: 'error';
-        loc: SourceLocation;
-        message: string;
-      }> = [
-        {
-          kind: 'error',
-          loc: derivedSetStateCall.value.callee.loc,
-          message: 'setState in effect',
-        },
-      ];
-
-      for (const usage of outsideEffectUsages) {
-        diagnosticDetails.push({
-          kind: 'error',
-          loc: usage,
-          message: 'setState outside effect',
-        });
-      }
-
-      let diagnostic = CompilerDiagnostic.create({
-        description: description,
-        category: ErrorCategory.EffectDerivationsOfState,
-        reason:
-          'Consider hoisting state to parent and making this a controlled component',
-      });
-
-      for (const detail of diagnosticDetails) {
-        diagnostic = diagnostic.withDetails(detail);
-      }
-
-      context.errors.pushDiagnostic(diagnostic);
     }
   }
 }

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-invalid-jsx-in-catch-in-outer-try-with-finally.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoJSXInTryStatements @outputMode:"lint"
+// @validateNoJSXInTryStatements
 import {identity} from 'shared-runtime';
 
 function Component(props) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-invalid-jsx-in-catch-in-outer-try-with-finally.js

@@ -1,4 +1,4 @@
-// @validateNoJSXInTryStatements @outputMode:"lint"
+// @validateNoJSXInTryStatements
 import {identity} from 'shared-runtime';
 
 function Component(props) {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-invalid-jsx-in-try-with-finally.expect.md

@@ -2,7 +2,7 @@
 ## Input
 
 ```javascript
-// @validateNoJSXInTryStatements @outputMode:"lint"
+// @validateNoJSXInTryStatements
 function Component(props) {
   let el;
   try {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-invalid-jsx-in-try-with-finally.js

@@ -1,4 +1,4 @@
-// @validateNoJSXInTryStatements @outputMode:"lint"
+// @validateNoJSXInTryStatements
 function Component(props) {
   let el;
   try {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-missing-source-locations.expect.md

@@ -10,28 +10,14 @@ function Component({prop1, prop2}) {
   const y = x * 2;
   const arr = [x, y];
   const obj = {x, y};
-  let destA, destB;
-  if (y > 5) {
-    [destA, destB] = arr;
-  }
-
   const [a, b] = arr;
   const {x: c, y: d} = obj;
-  let sound;
-
-  if (y > 10) {
-    sound = 'woof';
-  } else {
-    sound = 'meow';
-  }
 
   useEffect(() => {
     if (a > 10) {
       console.log(a);
-      console.log(sound);
-      console.log(destA, destB);
     }
-  }, [a, sound, destA, destB]);
+  }, [a]);
 
   const foo = useCallback(() => {
     return a + b;
@@ -52,343 +38,187 @@ function Component({prop1, prop2}) {
 ## Error
 
 ```
-Found 25 errors:
+Found 13 errors:
 
 Todo: Important source location missing in generated code
 
-Source location for Identifier is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
+Source location for VariableDeclarator is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
 
-error.todo-missing-source-locations.ts:4:9
-  2 | import {useEffect, useCallback} from 'react';
+error.todo-missing-source-locations.ts:5:8
   3 |
-> 4 | function Component({prop1, prop2}) {
-    |          ^^^^^^^^^
-  5 |   const x = prop1 + prop2;
+  4 | function Component({prop1, prop2}) {
+> 5 |   const x = prop1 + prop2;
+    |         ^^^^^^^^^^^^^^^^^
   6 |   const y = x * 2;
   7 |   const arr = [x, y];
+  8 |   const obj = {x, y};
 
 Todo: Important source location missing in generated code
 
-Source location for VariableDeclaration is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
+Source location for VariableDeclarator is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
 
-error.todo-missing-source-locations.ts:9:2
+error.todo-missing-source-locations.ts:6:8
+  4 | function Component({prop1, prop2}) {
+  5 |   const x = prop1 + prop2;
+> 6 |   const y = x * 2;
+    |         ^^^^^^^^^
+  7 |   const arr = [x, y];
+  8 |   const obj = {x, y};
+  9 |   const [a, b] = arr;
+
+Todo: Important source location missing in generated code
+
+Source location for VariableDeclarator is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
+
+error.todo-missing-source-locations.ts:7:8
+   5 |   const x = prop1 + prop2;
+   6 |   const y = x * 2;
+>  7 |   const arr = [x, y];
+     |         ^^^^^^^^^^^^
+   8 |   const obj = {x, y};
+   9 |   const [a, b] = arr;
+  10 |   const {x: c, y: d} = obj;
+
+Todo: Important source location missing in generated code
+
+Source location for VariableDeclarator is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
+
+error.todo-missing-source-locations.ts:8:8
+   6 |   const y = x * 2;
+   7 |   const arr = [x, y];
+>  8 |   const obj = {x, y};
+     |         ^^^^^^^^^^^^
+   9 |   const [a, b] = arr;
+  10 |   const {x: c, y: d} = obj;
+  11 |
+
+Todo: Important source location missing in generated code
+
+Source location for VariableDeclarator is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
+
+error.todo-missing-source-locations.ts:9:8
    7 |   const arr = [x, y];
    8 |   const obj = {x, y};
->  9 |   let destA, destB;
+>  9 |   const [a, b] = arr;
+     |         ^^^^^^^^^^^^
+  10 |   const {x: c, y: d} = obj;
+  11 |
+  12 |   useEffect(() => {
+
+Todo: Important source location missing in generated code
+
+Source location for VariableDeclarator is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
+
+error.todo-missing-source-locations.ts:10:8
+   8 |   const obj = {x, y};
+   9 |   const [a, b] = arr;
+> 10 |   const {x: c, y: d} = obj;
+     |         ^^^^^^^^^^^^^^^^^^
+  11 |
+  12 |   useEffect(() => {
+  13 |     if (a > 10) {
+
+Todo: Important source location missing in generated code
+
+Source location for ExpressionStatement is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
+
+error.todo-missing-source-locations.ts:12:2
+  10 |   const {x: c, y: d} = obj;
+  11 |
+> 12 |   useEffect(() => {
      |   ^^^^^^^^^^^^^^^^^
-  10 |   if (y > 5) {
-  11 |     [destA, destB] = arr;
-  12 |   }
+> 13 |     if (a > 10) {
+     | ^^^^^^^^^^^^^^^^^
+> 14 |       console.log(a);
+     | ^^^^^^^^^^^^^^^^^
+> 15 |     }
+     | ^^^^^^^^^^^^^^^^^
+> 16 |   }, [a]);
+     | ^^^^^^^^^^^
+  17 |
+  18 |   const foo = useCallback(() => {
+  19 |     return a + b;
 
 Todo: Important source location missing in generated code
 
 Source location for ExpressionStatement is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
 
-error.todo-missing-source-locations.ts:11:4
-   9 |   let destA, destB;
-  10 |   if (y > 5) {
-> 11 |     [destA, destB] = arr;
-     |     ^^^^^^^^^^^^^^^^^^^^^
-  12 |   }
-  13 |
-  14 |   const [a, b] = arr;
-
-Todo: Important source location missing in generated code
-
-Source location for Identifier is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:15:9
-  13 |
-  14 |   const [a, b] = arr;
-> 15 |   const {x: c, y: d} = obj;
-     |          ^
-  16 |   let sound;
-  17 |
-  18 |   if (y > 10) {
-
-Todo: Important source location missing in generated code
-
-Source location for Identifier is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:15:15
-  13 |
-  14 |   const [a, b] = arr;
-> 15 |   const {x: c, y: d} = obj;
-     |                ^
-  16 |   let sound;
-  17 |
-  18 |   if (y > 10) {
-
-Todo: Important source location missing in generated code
-
-Source location for VariableDeclaration is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:16:2
-  14 |   const [a, b] = arr;
-  15 |   const {x: c, y: d} = obj;
-> 16 |   let sound;
-     |   ^^^^^^^^^^
-  17 |
-  18 |   if (y > 10) {
-  19 |     sound = 'woof';
-
-Todo: Important source location missing in generated code
-
-Source location for ExpressionStatement is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:19:4
-  17 |
-  18 |   if (y > 10) {
-> 19 |     sound = 'woof';
-     |     ^^^^^^^^^^^^^^^
-  20 |   } else {
-  21 |     sound = 'meow';
-  22 |   }
-
-Todo: Important source location has wrong node type in generated code
-
-Source location for Identifier exists in the generated output but with wrong node type(s): ExpressionStatement. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:19:4
-  17 |
-  18 |   if (y > 10) {
-> 19 |     sound = 'woof';
-     |     ^^^^^
-  20 |   } else {
-  21 |     sound = 'meow';
-  22 |   }
-
-Todo: Important source location missing in generated code
-
-Source location for ExpressionStatement is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:21:4
-  19 |     sound = 'woof';
-  20 |   } else {
-> 21 |     sound = 'meow';
-     |     ^^^^^^^^^^^^^^^
-  22 |   }
-  23 |
-  24 |   useEffect(() => {
-
-Todo: Important source location has wrong node type in generated code
-
-Source location for Identifier exists in the generated output but with wrong node type(s): ExpressionStatement. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:21:4
-  19 |     sound = 'woof';
-  20 |   } else {
-> 21 |     sound = 'meow';
-     |     ^^^^^
-  22 |   }
-  23 |
-  24 |   useEffect(() => {
-
-Todo: Important source location missing in generated code
-
-Source location for ExpressionStatement is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:24:2
-  22 |   }
-  23 |
-> 24 |   useEffect(() => {
-     |   ^^^^^^^^^^^^^^^^^
-> 25 |     if (a > 10) {
-     | ^^^^^^^^^^^^^^^^^
-> 26 |       console.log(a);
-     | ^^^^^^^^^^^^^^^^^
-> 27 |       console.log(sound);
-     | ^^^^^^^^^^^^^^^^^
-> 28 |       console.log(destA, destB);
-     | ^^^^^^^^^^^^^^^^^
-> 29 |     }
-     | ^^^^^^^^^^^^^^^^^
-> 30 |   }, [a, sound, destA, destB]);
-     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-  31 |
-  32 |   const foo = useCallback(() => {
-  33 |     return a + b;
-
-Todo: Important source location missing in generated code
-
-Source location for ExpressionStatement is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:26:6
-  24 |   useEffect(() => {
-  25 |     if (a > 10) {
-> 26 |       console.log(a);
+error.todo-missing-source-locations.ts:14:6
+  12 |   useEffect(() => {
+  13 |     if (a > 10) {
+> 14 |       console.log(a);
      |       ^^^^^^^^^^^^^^^
-  27 |       console.log(sound);
-  28 |       console.log(destA, destB);
-  29 |     }
+  15 |     }
+  16 |   }, [a]);
+  17 |
 
 Todo: Important source location missing in generated code
 
-Source location for Identifier is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
+Source location for VariableDeclarator is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
 
-error.todo-missing-source-locations.ts:26:14
-  24 |   useEffect(() => {
-  25 |     if (a > 10) {
-> 26 |       console.log(a);
-     |               ^^^
-  27 |       console.log(sound);
-  28 |       console.log(destA, destB);
-  29 |     }
-
-Todo: Important source location missing in generated code
-
-Source location for ExpressionStatement is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:27:6
-  25 |     if (a > 10) {
-  26 |       console.log(a);
-> 27 |       console.log(sound);
-     |       ^^^^^^^^^^^^^^^^^^^
-  28 |       console.log(destA, destB);
-  29 |     }
-  30 |   }, [a, sound, destA, destB]);
-
-Todo: Important source location missing in generated code
-
-Source location for Identifier is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:27:14
-  25 |     if (a > 10) {
-  26 |       console.log(a);
-> 27 |       console.log(sound);
-     |               ^^^
-  28 |       console.log(destA, destB);
-  29 |     }
-  30 |   }, [a, sound, destA, destB]);
-
-Todo: Important source location missing in generated code
-
-Source location for ExpressionStatement is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:28:6
-  26 |       console.log(a);
-  27 |       console.log(sound);
-> 28 |       console.log(destA, destB);
-     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^
-  29 |     }
-  30 |   }, [a, sound, destA, destB]);
-  31 |
-
-Todo: Important source location missing in generated code
-
-Source location for Identifier is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:28:14
-  26 |       console.log(a);
-  27 |       console.log(sound);
-> 28 |       console.log(destA, destB);
-     |               ^^^
-  29 |     }
-  30 |   }, [a, sound, destA, destB]);
-  31 |
-
-Todo: Important source location missing in generated code
-
-Source location for Identifier is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:32:14
-  30 |   }, [a, sound, destA, destB]);
-  31 |
-> 32 |   const foo = useCallback(() => {
-     |               ^^^^^^^^^^^
-  33 |     return a + b;
-  34 |   }, [a, b]);
-  35 |
+error.todo-missing-source-locations.ts:18:8
+  16 |   }, [a]);
+  17 |
+> 18 |   const foo = useCallback(() => {
+     |         ^^^^^^^^^^^^^^^^^^^^^^^^^
+> 19 |     return a + b;
+     | ^^^^^^^^^^^^^^^^^
+> 20 |   }, [a, b]);
+     | ^^^^^^^^^^^^^
+  21 |
+  22 |   function bar() {
+  23 |     return (c + d) * 2;
 
 Todo: Important source location missing in generated code
 
 Source location for ReturnStatement is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
 
-error.todo-missing-source-locations.ts:33:4
-  31 |
-  32 |   const foo = useCallback(() => {
-> 33 |     return a + b;
+error.todo-missing-source-locations.ts:19:4
+  17 |
+  18 |   const foo = useCallback(() => {
+> 19 |     return a + b;
      |     ^^^^^^^^^^^^^
-  34 |   }, [a, b]);
-  35 |
-  36 |   function bar() {
-
-Todo: Important source location missing in generated code
-
-Source location for Identifier is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:34:6
-  32 |   const foo = useCallback(() => {
-  33 |     return a + b;
-> 34 |   }, [a, b]);
-     |       ^
-  35 |
-  36 |   function bar() {
-  37 |     return (c + d) * 2;
-
-Todo: Important source location missing in generated code
-
-Source location for Identifier is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:34:9
-  32 |   const foo = useCallback(() => {
-  33 |     return a + b;
-> 34 |   }, [a, b]);
-     |          ^
-  35 |
-  36 |   function bar() {
-  37 |     return (c + d) * 2;
+  20 |   }, [a, b]);
+  21 |
+  22 |   function bar() {
 
 Todo: Important source location missing in generated code
 
 Source location for ReturnStatement is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
 
-error.todo-missing-source-locations.ts:37:4
-  35 |
-  36 |   function bar() {
-> 37 |     return (c + d) * 2;
+error.todo-missing-source-locations.ts:23:4
+  21 |
+  22 |   function bar() {
+> 23 |     return (c + d) * 2;
      |     ^^^^^^^^^^^^^^^^^^^
-  38 |   }
-  39 |
-  40 |   console.log('Hello, world!');
+  24 |   }
+  25 |
+  26 |   console.log('Hello, world!');
 
 Todo: Important source location missing in generated code
 
 Source location for ExpressionStatement is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
 
-error.todo-missing-source-locations.ts:40:2
-  38 |   }
-  39 |
-> 40 |   console.log('Hello, world!');
+error.todo-missing-source-locations.ts:26:2
+  24 |   }
+  25 |
+> 26 |   console.log('Hello, world!');
      |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-  41 |
-  42 |   return [y, foo, bar];
-  43 | }
-
-Todo: Important source location missing in generated code
-
-Source location for Identifier is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
-
-error.todo-missing-source-locations.ts:40:10
-  38 |   }
-  39 |
-> 40 |   console.log('Hello, world!');
-     |           ^^^
-  41 |
-  42 |   return [y, foo, bar];
-  43 | }
+  27 |
+  28 |   return [y, foo, bar];
+  29 | }
 
 Todo: Important source location missing in generated code
 
 Source location for ReturnStatement is missing in the generated output. This can cause coverage instrumentation to fail to track this code properly, resulting in inaccurate coverage reports..
 
-error.todo-missing-source-locations.ts:42:2
-  40 |   console.log('Hello, world!');
-  41 |
-> 42 |   return [y, foo, bar];
+error.todo-missing-source-locations.ts:28:2
+  26 |   console.log('Hello, world!');
+  27 |
+> 28 |   return [y, foo, bar];
      |   ^^^^^^^^^^^^^^^^^^^^^
-  43 | }
-  44 |
+  29 | }
+  30 |
 ```
           
       

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.todo-missing-source-locations.js

@@ -6,28 +6,14 @@ function Component({prop1, prop2}) {
   const y = x * 2;
   const arr = [x, y];
   const obj = {x, y};
-  let destA, destB;
-  if (y > 5) {
-    [destA, destB] = arr;
-  }
-
   const [a, b] = arr;
   const {x: c, y: d} = obj;
-  let sound;
-
-  if (y > 10) {
-    sound = 'woof';
-  } else {
-    sound = 'meow';
-  }
 
   useEffect(() => {
     if (a > 10) {
       console.log(a);
-      console.log(sound);
-      console.log(destA, destB);
     }
-  }, [a, sound, destA, destB]);
+  }, [a]);
 
   const foo = useCallback(() => {
     return a + b;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/escape-analysis-non-escaping-interleaved-allocating-nested-dependency.expect.md

@@ -44,6 +44,7 @@ function Component(props) {
   let t0;
   if ($[0] !== props.a) {
     const a = [props.a];
+
     t0 = [a];
     $[0] = props.a;
     $[1] = t0;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/fbt/fbt-param-with-newline.expect.md

@@ -40,11 +40,13 @@ function Component(props) {
       [
         fbt._param(
           "a really long description that got split into multiple lines",
+
           props.name,
         ),
       ],
       { hk: "1euPUp" },
     );
+
     t0 = element.toString();
     $[0] = props.name;
     $[1] = t0;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/fbt/fbt-param-with-quotes.expect.md

@@ -32,9 +32,16 @@ function Component(props) {
   if ($[0] !== props.name) {
     const element = fbt._(
       'Hello {"user" name}',
-      [fbt._param('"user" name', props.name)],
+      [
+        fbt._param(
+          '"user" name',
+
+          props.name,
+        ),
+      ],
       { hk: "S0vMe" },
     );
+
     t0 = element.toString();
     $[0] = props.name;
     $[1] = t0;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/fbt/fbt-param-with-unicode.expect.md

@@ -32,9 +32,16 @@ function Component(props) {
   if ($[0] !== props.name) {
     const element = fbt._(
       "Hello {user name ☺}",
-      [fbt._param("user name \u263A", props.name)],
+      [
+        fbt._param(
+          "user name \u263A",
+
+          props.name,
+        ),
+      ],
       { hk: "1En1lp" },
     );
+
     t0 = element.toString();
     $[0] = props.name;
     $[1] = t0;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/fbt/fbt-to-string.expect.md

@@ -32,9 +32,16 @@ function Component(props) {
   if ($[0] !== props.name) {
     const element = fbt._(
       "Hello {user name}",
-      [fbt._param("user name", props.name)],
+      [
+        fbt._param(
+          "user name",
+
+          props.name,
+        ),
+      ],
       { hk: "2zEDKF" },
     );
+
     t0 = element.toString();
     $[0] = props.name;
     $[1] = t0;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/flag-enable-emit-hook-guards.expect.md

@@ -78,6 +78,7 @@ function Component(t0) {
           setState(5);
         }
       };
+
       t3 = [state];
       $[1] = state;
       $[2] = t2;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-in-statement.expect.md

@@ -33,6 +33,7 @@ function Component(props) {
     for (const key in props) {
       items.push(<div key={key}>{key}</div>);
     }
+
     t0 = <div>{items}</div>;
     $[0] = props;
     $[1] = t0;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-loop-with-value-block-initializer.expect.md

@@ -73,6 +73,7 @@ function Component(props) {
       const item = props.items[i];
       items.push(<div key={item.id}>{item.value}</div>);
     }
+
     t0 = <div>{items}</div>;
     $[0] = props.items;
     $[1] = props.start;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/for-of-mutate.expect.md

@@ -38,6 +38,7 @@ function Component(_props) {
         <div key={toJSON(item)}>{toJSON(mutateAndReturn(item))}</div>,
       );
     }
+
     t0 = <div>{results}</div>;
     $[0] = t0;
   } else {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/function-expression-maybe-mutates-hook-return-value.expect.md

@@ -29,6 +29,7 @@ function Component(props) {
     const onLoad = () => {
       log(id);
     };
+
     t0 = <Foo onLoad={onLoad} />;
     $[0] = id;
     $[1] = t0;

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

@@ -27,6 +27,7 @@ function Component(props) {
     const f = function () {
       return <div>{props.name}</div>;
     };
+
     t0 = f.call();
     $[0] = props;
     $[1] = t0;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/global-jsx-tag-lowered-between-mutations.expect.md

@@ -29,6 +29,7 @@ function Component(props) {
   let t0;
   if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
     const maybeMutable = new MaybeMutable();
+
     t0 = <View>{maybeMutate(maybeMutable)}</View>;
     $[0] = t0;
   } else {

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/global-types/set-constructor-arg.expect.md

@@ -60,6 +60,7 @@ function useFoo(t0) {
   if ($[3] !== propArr[1] || $[4] !== propArr[2]) {
     s2 = new Set(MODULE_LOCAL.values());
     s2.add(propArr[1]);
+
     s3 = new Set(s2.values());
     s3.add(propArr[2]);
     $[3] = propArr[1];

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/global-types/set-copy-constructor-mutate.expect.md

@@ -41,6 +41,7 @@ function useFoo(t0) {
   if ($[0] !== propArr[0]) {
     s1 = new Set([1, 2, 3]);
     s1.add(makeArray(propArr[0]));
+
     s2 = new Set(s1);
 
     mutate(s2);

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

@@ -37,6 +37,7 @@ function Foo() {
         </div>
       );
     };
+
     const [t1, t2] = [1, { x: 2 }];
     const a = t1;
     const { x: t3, y: t4 } = t2;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/hoisting-computed-member-expression.expect.md

@@ -39,11 +39,14 @@ function hoisting() {
     const onClick = function onClick() {
       return bar.baz;
     };
+
     const onClick2 = function onClick2() {
       return bar[baz];
     };
+
     const baz = "baz";
     const bar = { baz: 1 };
+
     t0 = (
       <Stringify onClick={onClick} onClick2={onClick2} shouldInvokeFns={true} />
     );