import { describe, it, expect, vi, beforeEach } from "vitest";

vi.unmock("../middleware/usage.js");

describe("usage shutdown race condition fix", () => {
  it("should NOT register SIGTERM/SIGINT handlers as module-level side effects", async () => {
    const onSpy = vi.spyOn(process, "on");
    vi.resetModules();
    
    // Track which signals usage.ts registers
    const signalsBefore = onSpy.mock.calls.map(c => c[0]);
    
    await import("../middleware/usage.js");
    
    const signalsAfter = onSpy.mock.calls.map(c => c[0]);
    const newSignals = signalsAfter.slice(signalsBefore.length);
    
    // usage.ts should NOT register SIGTERM or SIGINT handlers
    const usageSignals = newSignals.filter(s => s === "SIGTERM" || s === "SIGINT");
    expect(usageSignals).toEqual([]);
    
    onSpy.mockRestore();
  });

  it("should export flushDirtyEntries for external shutdown orchestration", async () => {
    vi.resetModules();
    const usageMod = await import("../middleware/usage.js");
    expect(typeof usageMod.flushDirtyEntries).toBe("function");
  });
});