Handle status fanout rejections (Refs #66)

tests/unit/hooks-server.test.ts

@@ -0,0 +1,51 @@
+import type { Handle } from '@sveltejs/kit';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+vi.mock('../../src/lib/server/db/migrate.js', () => ({ migrate: vi.fn() }));
+vi.mock('../../src/lib/server/pipeline/worker.js', () => ({ startWorker: vi.fn() }));
+vi.mock('../../src/lib/server/provisioning/history.js', () => ({ interruptDeployments: vi.fn() }));
+vi.mock('../../src/lib/server/auth/guard.js', () => ({ authenticationHandle: vi.fn(async () => new Response('OK')) }));
+vi.mock('../../src/lib/server/pipeline/bus.js', () => ({ invalidateFleet: vi.fn() }));
+vi.mock('../../src/lib/server/performance.js', () => ({ startPerformanceMonitor: vi.fn() }));
+
+let originalListeners = process.listeners('unhandledRejection');
+beforeEach(() => {
+    vi.resetModules(); vi.clearAllMocks();
+    originalListeners = process.listeners('unhandledRejection');
+});
+afterEach(() => {
+    for (const listener of process.listeners('unhandledRejection')) {
+        if (!originalListeners.includes(listener)) process.off('unhandledRejection', listener);
+    }
+    vi.restoreAllMocks();
+});
+
+describe('controller error handling', () => {
+    it('registers one process rejection logger before starting workers, even across requests', async () => {
+        const on = vi.spyOn(process, 'on');
+        const log = vi.spyOn(console, 'error').mockImplementation(() => {});
+        const { handle } = await import('../../src/hooks.server.js');
+        const { startWorker } = await import('../../src/lib/server/pipeline/worker.js');
+        const input = {
+            event: { request: new Request('http://localhost/'), route: { id: '/' }, locals: {} },
+            resolve: vi.fn()
+        } as unknown as Parameters<Handle>[0];
+
+        await handle(input);
+        await handle(input);
+
+        const listeners = process.listeners('unhandledRejection').filter(listener => !originalListeners.includes(listener));
+        expect(listeners).toHaveLength(1);
+        expect(startWorker).toHaveBeenCalledTimes(1);
+        const registration = on.mock.calls.findIndex(([event]) => event === 'unhandledRejection');
+        expect(on.mock.invocationCallOrder[registration]).toBeLessThan(vi.mocked(startWorker).mock.invocationCallOrder[0]);
+
+        const failure = new Error('unexpected background failure');
+        listeners[0](failure, Promise.resolve());
+        listeners[0]('non-Error rejection', Promise.resolve());
+        expect(log.mock.calls).toEqual([
+            ['[process] unhandled rejection:', failure],
+            ['[process] unhandled rejection:', 'non-Error rejection']
+        ]);
+    });
+});