fix: stop test-parallel from waiting forever on child close

test/scripts/test-planner.executor-fallback.test.ts

@@ -0,0 +1,52 @@
+import { EventEmitter } from "node:events";
+import { PassThrough } from "node:stream";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { importFreshModule } from "../helpers/import-fresh.js";
+
+afterEach(() => {
+  vi.restoreAllMocks();
+  vi.resetModules();
+});
+
+describe("test planner executor", () => {
+  it("falls back to child exit when close never arrives", async () => {
+    const stdout = new PassThrough();
+    const stderr = new PassThrough();
+    const fakeChild = Object.assign(new EventEmitter(), {
+      stdout,
+      stderr,
+      pid: 12345,
+      kill: vi.fn(),
+    });
+    const spawnMock = vi.fn(() => {
+      setTimeout(() => {
+        fakeChild.emit("exit", 0, null);
+      }, 0);
+      return fakeChild;
+    });
+    vi.doMock("node:child_process", () => ({
+      spawn: spawnMock,
+    }));
+
+    const { executePlan, createExecutionArtifacts } = await importFreshModule<
+      typeof import("../../scripts/test-planner/executor.mjs")
+    >(import.meta.url, "../../scripts/test-planner/executor.mjs?scope=exit-fallback");
+    const artifacts = createExecutionArtifacts({ OPENCLAW_TEST_CLOSE_GRACE_MS: "10" });
+    const executePromise = executePlan(
+      {
+        passthroughMetadataOnly: true,
+        passthroughOptionArgs: [],
+        runtimeCapabilities: { isWindowsCi: false, isCI: false, isWindows: false },
+      },
+      {
+        env: { OPENCLAW_TEST_CLOSE_GRACE_MS: "10" },
+        artifacts,
+      },
+    );
+
+    await expect(executePromise).resolves.toBe(0);
+    expect(spawnMock).toHaveBeenCalledTimes(1);
+
+    artifacts.cleanupTempArtifacts();
+  });
+});