feat(api): idle container reaper (MS22-P1k) (#614)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/api/src/container-reaper/container-reaper.service.spec.ts

@@ -0,0 +1,45 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import type { ContainerLifecycleService } from "../container-lifecycle/container-lifecycle.service";
+import { ContainerReaperService } from "./container-reaper.service";
+
+describe("ContainerReaperService", () => {
+  let service: ContainerReaperService;
+  let containerLifecycle: Pick<ContainerLifecycleService, "reapIdle">;
+
+  beforeEach(() => {
+    containerLifecycle = {
+      reapIdle: vi.fn(),
+    };
+    service = new ContainerReaperService(containerLifecycle as ContainerLifecycleService);
+  });
+
+  it("reapIdleContainers calls containerLifecycle.reapIdle()", async () => {
+    vi.mocked(containerLifecycle.reapIdle).mockResolvedValue({ stopped: [] });
+
+    await service.reapIdleContainers();
+
+    expect(containerLifecycle.reapIdle).toHaveBeenCalledTimes(1);
+  });
+
+  it("reapIdleContainers handles errors gracefully", async () => {
+    const error = new Error("reap failure");
+    vi.mocked(containerLifecycle.reapIdle).mockRejectedValue(error);
+    const loggerError = vi.spyOn(service["logger"], "error").mockImplementation(() => {});
+
+    await expect(service.reapIdleContainers()).resolves.toBeUndefined();
+
+    expect(loggerError).toHaveBeenCalledWith(
+      "Failed to reap idle containers",
+      expect.stringContaining("reap failure")
+    );
+  });
+
+  it("reapIdleContainers logs stopped container count", async () => {
+    vi.mocked(containerLifecycle.reapIdle).mockResolvedValue({ stopped: ["user-1", "user-2"] });
+    const loggerLog = vi.spyOn(service["logger"], "log").mockImplementation(() => {});
+
+    await service.reapIdleContainers();
+
+    expect(loggerLog).toHaveBeenCalledWith("Stopped 2 idle containers: user-1, user-2");
+  });
+});