[world-local] Reject run_failed on non-existent run

.changeset/world-local-run-failed-not-found.md

@@ -0,0 +1,5 @@
+---
+"@workflow/world-local": patch
+---
+
+Throw `WorkflowRunNotFoundError` when `run_failed` is recorded against a run that doesn't exist, matching the behaviour of `world-postgres` and `world-vercel`.

packages/world-local/src/storage.test.ts

@@ -276,6 +276,14 @@ describe('Storage', () => {
         expect(updated.error?.message).toBe('Something went wrong');
         expect(updated.completedAt).toBeInstanceOf(Date);
       });
+
+      it('should reject run_failed on non-existent run', async () => {
+        await expect(
+          updateRun(storage, 'wrun_nonexistent', 'run_failed', {
+            error: 'Something went wrong',
+          })
+        ).rejects.toMatchObject({ name: 'WorkflowRunNotFoundError' });
+      });
     });
 
     describe('list', () => {

packages/world-local/src/storage/events-storage.ts

@@ -6,6 +6,7 @@ import {
   RunExpiredError,
   RunNotSupportedError,
   TooEarlyError,
+  WorkflowRunNotFoundError,
   WorkflowWorldError,
 } from '@workflow/errors';
 import type {
@@ -226,6 +227,14 @@ export function createEventsStorage(
         }
       }
 
+      // run_failed on a non-existent run is rejected to match the
+      // postgres and vercel worlds, which both surface this as a
+      // WorkflowRunNotFoundError rather than silently persisting an
+      // event for a run that was never created.
+      if (data.eventType === 'run_failed' && !currentRun) {
+        throw new WorkflowRunNotFoundError(effectiveRunId);
+      }
+
       // ============================================================
       // VERSION COMPATIBILITY: Check run spec version
       // ============================================================