Coalesce fleet refreshes and suppress unchanged sweep events

2026-10-05 15:29:03 -04:00
parent 2af768011a
commit 030794635e
5 changed files with 198 additions and 5 deletions
@@ -0,0 +1,118 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+vi.mock('$app/environment', () => ({ browser: true }));
+
+let documentStub: EventTarget & { visibilityState: string };
+let stop: (() => void) | undefined;
+const changed = () => window.dispatchEvent(new Event('ec:fleet-changed'));
+const visibility = (state: string) => {
+    documentStub.visibilityState = state;
+    documentStub.dispatchEvent(new Event('visibilitychange'));
+};
+const response = (url: string) => Response.json(url === '/api/servers'
+    ? { serverNow: Date.now(), servers: [], integrations: {} } : { operations: [] });
+
+beforeEach(() => {
+    vi.resetModules();
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date('2026-10-05T12:00:00Z'));
+    documentStub = Object.assign(new EventTarget(), { visibilityState: 'visible' });
+    vi.stubGlobal('document', documentStub);
+    vi.stubGlobal('window', new EventTarget());
+    vi.stubGlobal('fetch', vi.fn(async (url: string) => response(url)));
+});
+afterEach(() => {
+    stop?.(); stop = undefined;
+    vi.useRealTimers(); vi.unstubAllGlobals(); vi.restoreAllMocks();
+});
+async function setup() {
+    const store = await import('../../src/lib/ui/stores/fleet.js');
+    store.fleet.set({ servers: [], operations: [], receivedAt: Date.now() });
+    stop = store.startFleetMonitor();
+    return store;
+}
+
+describe('fleet event refreshes', () => {
+    it('coalesces bursts and refreshes at most once every two seconds with a trailing refresh', async () => {
+        await setup();
+        changed(); changed(); changed();
+        await vi.advanceTimersByTimeAsync(249);
+        expect(fetch).not.toHaveBeenCalled();
+        await vi.advanceTimersByTimeAsync(1);
+        expect(fetch).toHaveBeenCalledTimes(2);
+        for (let i = 0; i < 7; i++) {
+            changed();
+            await vi.advanceTimersByTimeAsync(250);
+            expect(fetch).toHaveBeenCalledTimes(2);
+        }
+        await vi.advanceTimersByTimeAsync(250);
+        expect(fetch).toHaveBeenCalledTimes(4);
+        changed();
+        await vi.advanceTimersByTimeAsync(2000);
+        expect(fetch).toHaveBeenCalledTimes(6);
+        await vi.advanceTimersByTimeAsync(5000);
+        expect(fetch).toHaveBeenCalledTimes(6);
+    });
+
+    it('keeps events during a request without an immediate follow-up when it finishes', async () => {
+        await setup();
+        let finish!: () => void;
+        const gate = new Promise<void>(resolve => { finish = resolve; });
+        vi.mocked(fetch).mockImplementation(async url => { await gate; return response(String(url)); });
+        changed();
+        await vi.advanceTimersByTimeAsync(250);
+        expect(fetch).toHaveBeenCalledTimes(2);
+        changed(); changed();
+        await vi.advanceTimersByTimeAsync(500);
+        finish();
+        await vi.advanceTimersByTimeAsync(1499);
+        expect(fetch).toHaveBeenCalledTimes(2);
+        await vi.advanceTimersByTimeAsync(1);
+        expect(fetch).toHaveBeenCalledTimes(4);
+    });
+
+    it('waits for a slow manual refresh and coalesces events arriving during it', async () => {
+        const { refreshFleet } = await setup();
+        let finish!: () => void;
+        const gate = new Promise<void>(resolve => { finish = resolve; });
+        vi.mocked(fetch).mockImplementation(async url => { await gate; return response(String(url)); });
+        const manual = refreshFleet();
+        changed();
+        await vi.advanceTimersByTimeAsync(3000);
+        changed(); changed();
+        expect(fetch).toHaveBeenCalledTimes(2);
+        finish(); await manual;
+        await vi.advanceTimersByTimeAsync(0);
+        expect(fetch).toHaveBeenCalledTimes(4);
+        await vi.advanceTimersByTimeAsync(3000);
+        expect(fetch).toHaveBeenCalledTimes(4);
+    });
+
+    it('skips queued refreshes while hidden, refreshes on return, and cancels on stop', async () => {
+        await setup();
+        changed(); visibility('hidden');
+        await vi.advanceTimersByTimeAsync(250);
+        changed();
+        await vi.advanceTimersByTimeAsync(3000);
+        expect(fetch).not.toHaveBeenCalled();
+        visibility('visible');
+        await vi.advanceTimersByTimeAsync(0);
+        expect(fetch).toHaveBeenCalledTimes(2);
+        changed(); stop!();
+        await vi.advanceTimersByTimeAsync(3000);
+        expect(fetch).toHaveBeenCalledTimes(2);
+    });
+
+    it('cancels a follow-up waiting for an active request when stopped', async () => {
+        const { refreshFleet } = await setup();
+        let finish!: () => void;
+        const gate = new Promise<void>(resolve => { finish = resolve; });
+        vi.mocked(fetch).mockImplementation(async url => { await gate; return response(String(url)); });
+        const manual = refreshFleet();
+        changed();
+        await vi.advanceTimersByTimeAsync(250);
+        stop!(); finish(); await manual;
+        await vi.advanceTimersByTimeAsync(3000);
+        expect(fetch).toHaveBeenCalledTimes(2);
+    });
+});