feat(FN-2506): merge fusion/fn-2506

packages/engine/src/runtimes/__tests__/in-process-runtime.test.ts

@@ -1042,7 +1042,52 @@ describe("InProcessRuntime", () => {
       }
     }, 30000);
 
-    it("warns on cleanup failure but does not throw", async () => {
+    it("does not warn when cleanup delete fails only because agent is already gone", async () => {
+      vi.useFakeTimers();
+      const warnSpy = vi.spyOn(runtimeLog, "warn");
+
+      try {
+        await runtime.start();
+
+        const store = getAgentStore(runtime);
+
+        // Create an ephemeral agent
+        const agent = await store.createAgent({
+          name: "executor-FN-BENIGN-1",
+          role: "executor",
+          metadata: {
+            agentKind: "task-worker",
+          },
+          runtimeConfig: { enabled: false },
+        });
+
+        const deleteAgentSpy = vi
+          .spyOn(store, "deleteAgent")
+          .mockRejectedValueOnce(new Error(`Agent ${agent.id} not found`));
+
+        // Emit termination event
+        store.emit("agent:stateChanged", agent.id, "running", "terminated");
+
+        // Wait for async handler, then fire delayed cleanup
+        await vi.advanceTimersByTimeAsync(0);
+        await vi.advanceTimersByTimeAsync(5000);
+
+        // Cleanup should still be attempted
+        expect(deleteAgentSpy).toHaveBeenCalledTimes(1);
+        expect(deleteAgentSpy).toHaveBeenCalledWith(agent.id);
+
+        // Benign not-found races should not produce warning-level noise
+        const emittedCleanupWarning = warnSpy.mock.calls.some(([msg]) =>
+          typeof msg === "string" && msg.includes("Failed to delete ephemeral agent"),
+        );
+        expect(emittedCleanupWarning).toBe(false);
+      } finally {
+        warnSpy.mockRestore();
+        vi.useRealTimers();
+      }
+    }, 30000);
+
+    it("warns on genuine cleanup failure but does not throw", async () => {
       vi.useFakeTimers();
       const warnSpy = vi.spyOn(runtimeLog, "warn");
 
@@ -1071,14 +1116,17 @@ describe("InProcessRuntime", () => {
         // Advance timers to trigger deletion
         await vi.advanceTimersByTimeAsync(5000);
 
-        // Should have logged a warning with concatenated message
-        expect(warnSpy).toHaveBeenCalledWith(
-          expect.stringContaining("Failed to delete ephemeral agent"),
-        );
-        // The warning message is a single concatenated string: "Failed to delete ephemeral agent {agentId} after termination: {error}"
-
         // Should have attempted deletion
         expect(deleteAgentSpy).toHaveBeenCalledTimes(1);
+        expect(deleteAgentSpy).toHaveBeenCalledWith(agent.id);
+
+        // Genuine failures still log warning-level context
+        const cleanupWarnings = warnSpy.mock.calls.filter(([msg]) =>
+          typeof msg === "string" && msg.includes("Failed to delete ephemeral agent"),
+        );
+        expect(cleanupWarnings).toHaveLength(1);
+        expect(cleanupWarnings[0]?.[0]).toContain(agent.id);
+        expect(cleanupWarnings[0]?.[0]).toContain("delete failed");
       } finally {
         warnSpy.mockRestore();
         vi.useRealTimers();

packages/engine/src/runtimes/in-process-runtime.ts

@@ -553,6 +553,9 @@ export class InProcessRuntime
                 try {
                   await this.agentStore?.deleteAgent(agentId);
                 } catch (err: unknown) {
+                  if (this.isBenignEphemeralDeleteRaceError(agentId, err)) {
+                    return;
+                  }
                   const msg = err instanceof Error ? err.message : String(err);
                   runtimeLog.warn(`Failed to delete ephemeral agent ${agentId} after termination: ${msg}`);
                 }
@@ -1087,6 +1090,25 @@ export class InProcessRuntime
     runtimeLog.log("Event forwarding setup complete");
   }
 
+  /**
+   * Returns true when an ephemeral delete failure is expected due to cleanup races
+   * (for example the agent was already removed by a parallel cleanup path).
+   */
+  private isBenignEphemeralDeleteRaceError(agentId: string, err: unknown): boolean {
+    const msg = err instanceof Error ? err.message : String(err);
+    const normalized = msg.toLowerCase();
+
+    if (normalized.includes("already deleted") || normalized.includes("already removed")) {
+      return true;
+    }
+
+    if (normalized.includes(`agent ${agentId.toLowerCase()} not found`)) {
+      return true;
+    }
+
+    return /^agent\s+.+\s+not found$/i.test(msg.trim());
+  }
+
   /**
    * Update status and emit health-changed event.
    */