test(boardwalk): cover the build id, the reload banner and the chunk reload guard (quick-261028-rqb)

admin/tests/app/chunkReload.test.ts

@@ -0,0 +1,99 @@
+import { describe, expect, it, vi } from 'vitest'
+import {
+  CHUNK_RELOAD_KEY,
+  CHUNK_RELOAD_WINDOW,
+  installChunkReloadGuard,
+  shouldReload,
+} from '../../src/app/chunkReload'
+
+/** An in-memory Storage. */
+function memoryStorage(): Storage {
+  const items = new Map<string, string>()
+  return {
+    get length() {
+      return items.size
+    },
+    clear: () => items.clear(),
+    getItem: (key) => items.get(key) ?? null,
+    key: (index) => [...items.keys()][index] ?? null,
+    removeItem: (key) => void items.delete(key),
+    setItem: (key, value) => void items.set(key, String(value)),
+  }
+}
+
+describe('shouldReload', () => {
+  it('reloads once and records the time', () => {
+    const storage = memoryStorage()
+    expect(shouldReload(storage, 1000)).toBe(true)
+    expect(storage.getItem(CHUNK_RELOAD_KEY)).toBe('1000')
+  })
+
+  it('declines a second reload within the window and allows one after it', () => {
+    const storage = memoryStorage()
+    expect(shouldReload(storage, 1000)).toBe(true)
+    expect(shouldReload(storage, 1000 + CHUNK_RELOAD_WINDOW - 1)).toBe(false)
+    expect(shouldReload(storage, 1000 + CHUNK_RELOAD_WINDOW)).toBe(true)
+    expect(storage.getItem(CHUNK_RELOAD_KEY)).toBe(String(1000 + CHUNK_RELOAD_WINDOW))
+  })
+
+  it('reloads over a stored value that is not a timestamp', () => {
+    const storage = memoryStorage()
+    storage.setItem(CHUNK_RELOAD_KEY, 'garbage')
+    expect(shouldReload(storage, 1000)).toBe(true)
+  })
+
+  it('never reloads without storage', () => {
+    expect(shouldReload(null, 1000)).toBe(false)
+  })
+
+  it('never reloads when storage throws', () => {
+    const reading = memoryStorage()
+    reading.getItem = () => {
+      throw new Error('denied')
+    }
+    expect(shouldReload(reading, 1000)).toBe(false)
+    const writing = memoryStorage()
+    writing.setItem = () => {
+      throw new Error('quota')
+    }
+    expect(shouldReload(writing, 1000)).toBe(false)
+  })
+
+  it('keys the flag under summer-admin.* with a 60 second window', () => {
+    expect(CHUNK_RELOAD_KEY).toBe('summer-admin.chunk-reload')
+    expect(CHUNK_RELOAD_WINDOW).toBe(60_000)
+  })
+})
+
+describe('installChunkReloadGuard', () => {
+  it('reloads once on vite:preloadError and leaves the event to the importer', () => {
+    const target = new EventTarget()
+    const storage = memoryStorage()
+    const reload = vi.fn()
+    let clock = 5000
+    const uninstall = installChunkReloadGuard({ target, storage: () => storage, reload, now: () => clock })
+
+    const first = new Event('vite:preloadError', { cancelable: true })
+    target.dispatchEvent(first)
+    expect(reload).toHaveBeenCalledTimes(1)
+    expect(first.defaultPrevented).toBe(false)
+
+    clock += 1000
+    target.dispatchEvent(new Event('vite:preloadError', { cancelable: true }))
+    expect(reload).toHaveBeenCalledTimes(1)
+
+    uninstall()
+    clock += CHUNK_RELOAD_WINDOW
+    target.dispatchEvent(new Event('vite:preloadError', { cancelable: true }))
+    expect(reload).toHaveBeenCalledTimes(1)
+  })
+
+  it('does not reload when no storage is available', () => {
+    const target = new EventTarget()
+    const reload = vi.fn()
+    const uninstall = installChunkReloadGuard({ target, storage: () => null, reload })
+    target.dispatchEvent(new Event('vite:preloadError'))
+    expect(reload).not.toHaveBeenCalled()
+    uninstall()
+  })
+})