test(site): cover site card and icon cache (#561)

src/utils/__tests__/siteIconCache.spec.ts

@@ -0,0 +1,77 @@
+import { getCachedSiteIcon } from '@/utils/siteIconCache'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+let keySeed = 0
+
+function nextKey() {
+  keySeed += 1
+  return `site-icon-${keySeed}`
+}
+
+function deferred<T>() {
+  let resolve!: (value: T) => void
+  let reject!: (reason?: unknown) => void
+  const promise = new Promise<T>((resolvePromise, rejectPromise) => {
+    resolve = resolvePromise
+    reject = rejectPromise
+  })
+
+  return { promise, reject, resolve }
+}
+
+describe('site icon cache', () => {
+  beforeEach(() => {
+    vi.useFakeTimers()
+    vi.setSystemTime(new Date('2026-07-19T00:00:00Z'))
+  })
+
+  it('isolates site ids and reuses each value within the TTL', async () => {
+    const firstLoader = vi.fn().mockResolvedValue('first-icon')
+    const secondLoader = vi.fn().mockResolvedValue('second-icon')
+    const firstKey = nextKey()
+    const secondKey = nextKey()
+
+    await expect(getCachedSiteIcon(firstKey, firstLoader)).resolves.toBe('first-icon')
+    await expect(getCachedSiteIcon(secondKey, secondLoader)).resolves.toBe('second-icon')
+    await expect(getCachedSiteIcon(firstKey, vi.fn().mockResolvedValue('stale'))).resolves.toBe('first-icon')
+
+    expect(firstLoader).toHaveBeenCalledOnce()
+    expect(secondLoader).toHaveBeenCalledOnce()
+  })
+
+  it('coalesces concurrent requests for the same site', async () => {
+    const pending = deferred<string>()
+    const loader = vi.fn().mockReturnValue(pending.promise)
+    const key = nextKey()
+
+    const firstRequest = getCachedSiteIcon(key, loader)
+    const secondRequest = getCachedSiteIcon(key, loader)
+    expect(loader).toHaveBeenCalledOnce()
+
+    pending.resolve('shared-icon')
+    await expect(firstRequest).resolves.toBe('shared-icon')
+    await expect(secondRequest).resolves.toBe('shared-icon')
+  })
+
+  it('reloads an expired value after ten minutes', async () => {
+    const key = nextKey()
+    await expect(getCachedSiteIcon(key, vi.fn().mockResolvedValue('old-icon'))).resolves.toBe('old-icon')
+
+    vi.advanceTimersByTime(10 * 60 * 1000)
+    const refreshedLoader = vi.fn().mockResolvedValue('fresh-icon')
+
+    await expect(getCachedSiteIcon(key, refreshedLoader)).resolves.toBe('fresh-icon')
+    expect(refreshedLoader).toHaveBeenCalledOnce()
+  })
+
+  it('allows a retry after the loader rejects', async () => {
+    const key = nextKey()
+    await expect(getCachedSiteIcon(key, vi.fn().mockRejectedValue(new Error('temporary failure')))).rejects.toThrow(
+      'temporary failure',
+    )
+
+    const retryLoader = vi.fn().mockResolvedValue('recovered-icon')
+    await expect(getCachedSiteIcon(key, retryLoader)).resolves.toBe('recovered-icon')
+    expect(retryLoader).toHaveBeenCalledOnce()
+  })
+})