thats-me/frontend/test/vitest/settings-persist.spec.js

import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
import { createPinia, setActivePinia } from 'pinia'
import { createApiRouter } from './helpers'

let api = createApiRouter()

vi.mock('src/services/apiClient', () => ({
  API_BASE: 'http://api.test',
  apiJson: (...args) => api.apiJson(...args),
  apiFetch: vi.fn(),
  retryAfterMs: () => null,
  getToken: vi.fn(async () => 'token'),
  setToken: vi.fn(async () => {}),
  clearToken: vi.fn(async () => {}),
  onUnauthorized: vi.fn(() => () => {}),
  revokeToken: vi.fn(async () => {}),
  loginRemote: vi.fn(),
  ApiError: class ApiError extends Error {}
}))

const { useAuthStore } = await import('stores/auth')
const { useSettingsStore } = await import('stores/settings')
const { resetClientLogForTests, logEntries } = await import('src/services/clientLog')

function apiError(status, extra = {}) {
  return Object.assign(new Error(`HTTP ${status}`), { status, ...extra })
}

describe('settings store — the server copy is written sparingly', () => {
  let settingsStore
  let puts

  beforeEach(async () => {
    setActivePinia(createPinia())
    api = createApiRouter()
    resetClientLogForTests()
    puts = []
    // Only the timers: IndexedDB needs the real event loop.
    vi.useFakeTimers({ toFake: ['setTimeout', 'clearTimeout'] })

    api.always('/settings', (url, options) => {
      if (options.method !== 'PUT') return Promise.resolve({ data: null })
      puts.push(options.body.settings)
      return Promise.resolve({ data: options.body.settings })
    })

    const authStore = useAuthStore()
    settingsStore = useSettingsStore()
    authStore.currentUserId = 'remote-user-1'
    // The GET at start-up and the watchers behind it.
    await vi.advanceTimersByTimeAsync(2000)
    puts.length = 0
  })

  afterEach(() => {
    vi.useRealTimers()
  })

  it('bundles a burst of scroll positions into one PUT and skips identical payloads', async () => {
    for (let i = 1; i <= 20; i++) {
      settingsStore.saveTimelineScrollLeft(i * 10, true)
      await vi.advanceTimersByTimeAsync(100)
    }
    // Two seconds of scrolling, not a single request yet.
    expect(puts).toHaveLength(0)

    await vi.advanceTimersByTimeAsync(1500)
    expect(puts).toHaveLength(1)
    expect(puts[0].timelineScrollLeft).toBe(200)

    // The same value again changes nothing on the server.
    settingsStore.saveTimelineScrollLeft(200, true)
    await vi.advanceTimersByTimeAsync(3000)
    expect(puts).toHaveLength(1)

    settingsStore.saveTimelineScrollLeft(260, true)
    await vi.advanceTimersByTimeAsync(1500)
    expect(puts).toHaveLength(2)
    expect(puts[1].timelineScrollLeft).toBe(260)
  })

  it('retries a 429 quietly instead of telling the user the settings were lost', async () => {
    let attempts = 0
    api = createApiRouter()
    api.always('/settings', (url, options) => {
      if (options.method !== 'PUT') return Promise.resolve({ data: null })
      attempts += 1
      if (attempts === 1) return Promise.reject(apiError(429, { retryAfterMs: 2000 }))
      return Promise.resolve({ data: options.body.settings })
    })

    settingsStore.saveTimelineScrollLeft(50, true)
    await vi.advanceTimersByTimeAsync(1500)
    expect(attempts).toBe(1)
    expect(settingsStore.lastError).toBeNull()
    expect(logEntries.value.at(-1)).toMatchObject({ level: 'warning', scope: 'settings', context: { status: 429, attempt: 1 } })

    // Backoff (3 s) outlasts the Retry-After here; then it goes out again.
    await vi.advanceTimersByTimeAsync(2500)
    expect(attempts).toBe(1)
    await vi.advanceTimersByTimeAsync(600)
    expect(attempts).toBe(2)
    expect(settingsStore.lastError).toBeNull()

    // A change made while the retry was pending is included, not lost.
    settingsStore.saveTimelineScrollLeft(80, true)
    await vi.advanceTimersByTimeAsync(1500)
    expect(attempts).toBe(3)
  })

  it('reports a payload the server rejects', async () => {
    api = createApiRouter()
    api.always('/settings', (url, options) => (
      options.method === 'PUT'
        ? Promise.reject(apiError(422))
        : Promise.resolve({ data: null })
    ))

    settingsStore.saveTimelineScrollLeft(50, true)
    await vi.advanceTimersByTimeAsync(1500)

    expect(settingsStore.lastError).toBe('Die Einstellungen konnten nicht gespeichert werden.')
    expect(logEntries.value.at(-1)).toMatchObject({ level: 'error', scope: 'settings' })
  })

  it('sends nothing more once another store has taken over', async () => {
    settingsStore.saveTimelineScrollLeft(50, true)
    // A new Pinia, as the next test would create it.
    setActivePinia(createPinia())
    await vi.advanceTimersByTimeAsync(3000)
    expect(puts).toHaveLength(0)
  })
})