test: expand subagent announce completion coverage

src/agents/subagent-registry.steer-restart.test.ts

@@ -239,4 +239,67 @@ describe("subagent registry steer restarts", () => {
     expect(childRunIds.filter((id) => id === "run-parent")).toHaveLength(2);
     expect(childRunIds.filter((id) => id === "run-child")).toHaveLength(1);
   });
+
+  it("retries completion-mode announce delivery with backoff and then gives up after retry limit", async () => {
+    const callGateway = vi.mocked((await import("../gateway/call.js")).callGateway);
+    const originalCallGateway = callGateway.getMockImplementation();
+    callGateway.mockImplementation(async (request: unknown) => {
+      const typed = request as { method?: string };
+      if (typed.method === "agent.wait") {
+        return new Promise<unknown>(() => undefined);
+      }
+      if (originalCallGateway) {
+        return originalCallGateway(request as Parameters<typeof callGateway>[0]);
+      }
+      return {};
+    });
+
+    vi.useFakeTimers();
+    try {
+      announceSpy.mockResolvedValue(false);
+
+      mod.registerSubagentRun({
+        runId: "run-completion-retry",
+        childSessionKey: "agent:main:subagent:completion",
+        requesterSessionKey: "agent:main:main",
+        requesterDisplayKey: "main",
+        task: "completion retry",
+        cleanup: "keep",
+        expectsCompletionMessage: true,
+      });
+
+      lifecycleHandler?.({
+        stream: "lifecycle",
+        runId: "run-completion-retry",
+        data: { phase: "end" },
+      });
+
+      await vi.advanceTimersByTimeAsync(0);
+      expect(announceSpy).toHaveBeenCalledTimes(1);
+      expect(mod.listSubagentRunsForRequester("agent:main:main")[0]?.announceRetryCount).toBe(1);
+
+      await vi.advanceTimersByTimeAsync(999);
+      expect(announceSpy).toHaveBeenCalledTimes(1);
+      await vi.advanceTimersByTimeAsync(1);
+      expect(announceSpy).toHaveBeenCalledTimes(2);
+      expect(mod.listSubagentRunsForRequester("agent:main:main")[0]?.announceRetryCount).toBe(2);
+
+      await vi.advanceTimersByTimeAsync(1_999);
+      expect(announceSpy).toHaveBeenCalledTimes(2);
+      await vi.advanceTimersByTimeAsync(1);
+      expect(announceSpy).toHaveBeenCalledTimes(3);
+      expect(mod.listSubagentRunsForRequester("agent:main:main")[0]?.announceRetryCount).toBe(3);
+
+      await vi.advanceTimersByTimeAsync(10_000);
+      expect(announceSpy).toHaveBeenCalledTimes(3);
+      expect(mod.listSubagentRunsForRequester("agent:main:main")[0]?.cleanupCompletedAt).toBeTypeOf(
+        "number",
+      );
+    } finally {
+      if (originalCallGateway) {
+        callGateway.mockImplementation(originalCallGateway);
+      }
+      vi.useRealTimers();
+    }
+  });
 });