[compiler] Phase 8: Add multi-error test fixture and update plan

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

@@ -704,19 +704,21 @@ function tryCompileFunction(
   }
 
   try {
-    return {
-      kind: 'compile',
-      compiledFn: compileFn(
-        fn,
-        programContext.opts.environment,
-        fnType,
-        outputMode,
-        programContext,
-        programContext.opts.logger,
-        programContext.filename,
-        programContext.code,
-      ),
-    };
+    const result = compileFn(
+      fn,
+      programContext.opts.environment,
+      fnType,
+      outputMode,
+      programContext,
+      programContext.opts.logger,
+      programContext.filename,
+      programContext.code,
+    );
+    if (result.isOk()) {
+      return {kind: 'compile', compiledFn: result.unwrap()};
+    } else {
+      return {kind: 'error', error: result.unwrapErr()};
+    }
   } catch (err) {
     return {kind: 'error', error: err};
   }

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

@@ -8,7 +8,12 @@
 import * as t from '@babel/types';
 import {ZodError, z} from 'zod/v4';
 import {fromZodError} from 'zod-validation-error/v4';
-import {CompilerError} from '../CompilerError';
+import {
+  CompilerDiagnostic,
+  CompilerError,
+  CompilerErrorDetail,
+  ErrorCategory,
+} from '../CompilerError';
 import {CompilerOutputMode, Logger, ProgramContext} from '../Entrypoint';
 import {Err, Ok, Result} from '../Utils/Result';
 import {
@@ -545,6 +550,12 @@ export class Environment {
 
   #flowTypeEnvironment: FlowTypeEnv | null;
 
+  /**
+   * Accumulated compilation errors. Passes record errors here instead of
+   * throwing, so the pipeline can continue and report all errors at once.
+   */
+  #errors: CompilerError = new CompilerError();
+
   constructor(
     scope: BabelScope,
     fnType: ReactFunctionType,
@@ -709,6 +720,82 @@ export class Environment {
     }
   }
 
+  /**
+   * Record a single diagnostic or error detail on this environment.
+   * If the error is an Invariant, it is immediately thrown since invariants
+   * represent internal bugs that cannot be recovered from.
+   * Otherwise, the error is accumulated and optionally logged.
+   */
+  recordError(error: CompilerDiagnostic | CompilerErrorDetail): void {
+    if (error.category === ErrorCategory.Invariant) {
+      const compilerError = new CompilerError();
+      if (error instanceof CompilerDiagnostic) {
+        compilerError.pushDiagnostic(error);
+      } else {
+        compilerError.pushErrorDetail(error);
+      }
+      throw compilerError;
+    }
+    if (error instanceof CompilerDiagnostic) {
+      this.#errors.pushDiagnostic(error);
+    } else {
+      this.#errors.pushErrorDetail(error);
+    }
+    if (this.logger != null) {
+      this.logger.logEvent(this.filename, {
+        kind: 'CompileError',
+        detail: error,
+        fnLoc: null,
+      });
+    }
+  }
+
+  /**
+   * Record all diagnostics from a CompilerError onto this environment.
+   */
+  recordErrors(error: CompilerError): void {
+    for (const detail of error.details) {
+      this.recordError(detail);
+    }
+  }
+
+  /**
+   * Returns true if any errors have been recorded during compilation.
+   */
+  hasErrors(): boolean {
+    return this.#errors.hasAnyErrors();
+  }
+
+  /**
+   * Returns the accumulated CompilerError containing all recorded diagnostics.
+   */
+  aggregateErrors(): CompilerError {
+    return this.#errors;
+  }
+
+  /**
+   * Wraps a callback in try/catch: if the callback throws a CompilerError
+   * that is NOT an invariant, the error is recorded and execution continues.
+   * Non-CompilerError exceptions and invariants are re-thrown.
+   */
+  tryRecord(fn: () => void): void {
+    try {
+      fn();
+    } catch (err) {
+      if (err instanceof CompilerError) {
+        // Check if any detail is an invariant — if so, re-throw
+        for (const detail of err.details) {
+          if (detail.category === ErrorCategory.Invariant) {
+            throw err;
+          }
+        }
+        this.recordErrors(err);
+      } else {
+        throw err;
+      }
+    }
+  }
+
   isContextIdentifier(node: t.Identifier): boolean {
     return this.#contextIdentifiers.has(node);
   }

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

@@ -54,7 +54,7 @@ function lowerWithMutationAliasing(fn: HIRFunction): void {
   deadCodeElimination(fn);
   const functionEffects = inferMutationAliasingRanges(fn, {
     isFunctionExpression: true,
-  }).unwrap();
+  });
   rewriteInstructionKindsBasedOnReassignment(fn);
   inferReactiveScopeVariables(fn);
   fn.aliasingEffects = functionEffects;

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

@@ -31,7 +31,6 @@ import {
   makeInstructionId,
 } from '../HIR';
 import {createTemporaryPlace, markInstructionIds} from '../HIR/HIRBuilder';
-import {Result} from '../Utils/Result';
 
 type ManualMemoCallee = {
   kind: 'useMemo' | 'useCallback';
@@ -389,9 +388,7 @@ function extractManualMemoizationArgs(
  * This pass also validates that useMemo callbacks return a value (not void), ensuring that useMemo
  * is only used for memoizing values and not for running arbitrary side effects.
  */
-export function dropManualMemoization(
-  func: HIRFunction,
-): Result<void, CompilerError> {
+export function dropManualMemoization(func: HIRFunction): void {
   const errors = new CompilerError();
   const isValidationEnabled =
     func.env.config.validatePreserveExistingMemoizationGuarantees ||
@@ -553,7 +550,9 @@ export function dropManualMemoization(
     }
   }
 
-  return errors.asResult();
+  if (errors.hasAnyErrors()) {
+    func.env.recordErrors(errors);
+  }
 }
 
 function findOptionalPlaces(fn: HIRFunction): Set<IdentifierId> {

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

@@ -45,7 +45,7 @@ import {
   eachTerminalOperand,
   eachTerminalSuccessor,
 } from '../HIR/visitors';
-import {Ok, Result} from '../Utils/Result';
+
 import {
   assertExhaustive,
   getOrInsertDefault,
@@ -100,7 +100,7 @@ export function inferMutationAliasingEffects(
   {isFunctionExpression}: {isFunctionExpression: boolean} = {
     isFunctionExpression: false,
   },
-): Result<void, CompilerError> {
+): void {
   const initialState = InferenceState.empty(fn.env, isFunctionExpression);
 
   // Map of blocks to the last (merged) incoming state that was processed
@@ -220,7 +220,7 @@ export function inferMutationAliasingEffects(
       }
     }
   }
-  return Ok(undefined);
+  return;
 }
 
 function findHoistedContextDeclarations(

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

@@ -26,7 +26,7 @@ import {
   eachTerminalOperand,
 } from '../HIR/visitors';
 import {assertExhaustive, getOrInsertWith} from '../Utils/utils';
-import {Err, Ok, Result} from '../Utils/Result';
+
 import {AliasingEffect, MutationReason} from './AliasingEffects';
 
 /**
@@ -74,7 +74,7 @@ import {AliasingEffect, MutationReason} from './AliasingEffects';
 export function inferMutationAliasingRanges(
   fn: HIRFunction,
   {isFunctionExpression}: {isFunctionExpression: boolean},
-): Result<Array<AliasingEffect>, CompilerError> {
+): Array<AliasingEffect> {
   // The set of externally-visible effects
   const functionEffects: Array<AliasingEffect> = [];
 
@@ -547,10 +547,14 @@ export function inferMutationAliasingRanges(
     }
   }
 
-  if (errors.hasAnyErrors() && !isFunctionExpression) {
-    return Err(errors);
+  if (
+    errors.hasAnyErrors() &&
+    !isFunctionExpression &&
+    fn.env.enableValidations
+  ) {
+    fn.env.recordErrors(errors);
   }
-  return Ok(functionEffects);
+  return functionEffects;
 }
 
 function appendFunctionErrors(errors: CompilerError, fn: HIRFunction): void {

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

@@ -46,7 +46,7 @@ import {
 } from '../HIR/HIR';
 import {printIdentifier, printInstruction, printPlace} from '../HIR/PrintHIR';
 import {eachPatternOperand} from '../HIR/visitors';
-import {Err, Ok, Result} from '../Utils/Result';
+
 import {GuardKind} from '../Utils/RuntimeDiagnosticConstants';
 import {assertExhaustive} from '../Utils/utils';
 import {buildReactiveFunction} from './BuildReactiveFunction';
@@ -111,7 +111,7 @@ export function codegenFunction(
     uniqueIdentifiers: Set<string>;
     fbtOperands: Set<IdentifierId>;
   },
-): Result<CodegenFunction, CompilerError> {
+): CodegenFunction {
   const cx = new Context(
     fn.env,
     fn.id ?? '[[ anonymous ]]',
@@ -141,11 +141,7 @@ export function codegenFunction(
     };
   }
 
-  const compileResult = codegenReactiveFunction(cx, fn);
-  if (compileResult.isErr()) {
-    return compileResult;
-  }
-  const compiled = compileResult.unwrap();
+  const compiled = codegenReactiveFunction(cx, fn);
 
   const hookGuard = fn.env.config.enableEmitHookGuards;
   if (hookGuard != null && fn.env.outputMode === 'client') {
@@ -273,7 +269,7 @@ export function codegenFunction(
         emitInstrumentForget.globalGating,
       );
       if (assertResult.isErr()) {
-        return assertResult;
+        fn.env.recordErrors(assertResult.unwrapErr());
       }
     }
 
@@ -323,20 +319,17 @@ export function codegenFunction(
       ),
       reactiveFunction,
     );
-    if (codegen.isErr()) {
-      return codegen;
-    }
-    outlined.push({fn: codegen.unwrap(), type});
+    outlined.push({fn: codegen, type});
   }
   compiled.outlined = outlined;
 
-  return compileResult;
+  return compiled;
 }
 
 function codegenReactiveFunction(
   cx: Context,
   fn: ReactiveFunction,
-): Result<CodegenFunction, CompilerError> {
+): CodegenFunction {
   for (const param of fn.params) {
     const place = param.kind === 'Identifier' ? param : param.place;
     cx.temp.set(place.identifier.declarationId, null);
@@ -355,13 +348,13 @@ function codegenReactiveFunction(
   }
 
   if (cx.errors.hasAnyErrors()) {
-    return Err(cx.errors);
+    fn.env.recordErrors(cx.errors);
   }
 
   const countMemoBlockVisitor = new CountMemoBlockVisitor(fn.env);
   visitReactiveFunction(fn, countMemoBlockVisitor, undefined);
 
-  return Ok({
+  return {
     type: 'CodegenFunction',
     loc: fn.loc,
     id: fn.id !== null ? t.identifier(fn.id) : null,
@@ -376,7 +369,7 @@ function codegenReactiveFunction(
     prunedMemoBlocks: countMemoBlockVisitor.prunedMemoBlocks,
     prunedMemoValues: countMemoBlockVisitor.prunedMemoValues,
     outlined: [],
-  });
+  };
 }
 
 class CountMemoBlockVisitor extends ReactiveFunctionVisitor<void> {
@@ -1665,7 +1658,7 @@ function codegenInstructionValue(
                   cx.temp,
                 ),
                 reactiveFunction,
-              ).unwrap();
+              );
 
               /*
                * ObjectMethod builder must be backwards compatible with older versions of babel.
@@ -1864,7 +1857,7 @@ function codegenInstructionValue(
           cx.temp,
         ),
         reactiveFunction,
-      ).unwrap();
+      );
 
       if (instrValue.type === 'ArrowFunctionExpression') {
         let body: t.BlockStatement | t.Expression = fn.body;