workavia-calendar-front/__test__/features/websocket/utils/notificationStorm.test.tsx

import type { AppDispatch, RootState } from '@/app/store'
import { store } from '@/app/store'
import { refreshCalendarWithSyncToken } from '@/features/Calendars/services'
import { getDisplayedCalendarRange } from '@/utils'
import { updateCalendars } from '@/websocket/messaging/updateCalendars'

jest.mock('@/features/Calendars/services', () => ({
  refreshCalendarWithSyncToken: jest.fn()
}))

jest.mock('@/utils', () => ({
  getDisplayedCalendarRange: jest.fn(),
  findCalendarById: jest.requireActual('@/utils').findCalendarById
}))

jest.mock('@/app/store', () => ({
  store: {
    getState: jest.fn()
  }
}))

jest.useFakeTimers()
const mockDispatch = jest.fn()
const mockRange = {
  start: new Date('2025-01-15T10:00:00Z'),
  end: new Date('2025-01-16T10:00:00Z')
}
const mockState = {
  calendars: {
    list: {
      'cal1/entry1': { id: 'cal1/entry1', name: 'Calendar 1', syncToken: 1 },
      'cal2/entry2': { id: 'cal2/entry2', name: 'Calendar 2', syncToken: 1 },
      'cal/A': { id: 'cal/A', name: 'Cal A', syncToken: 1 },
      'cal/B': { id: 'cal/B', name: 'Cal B', syncToken: 1 },
      'cal/C': { id: 'cal/C', name: 'Cal C', syncToken: 1 }
    },
    templist: {}
  }
} as unknown as RootState
const mockAccumulators: {
  calendarsToRefresh: Map<string, any>
  calendarsToHide: Set<string>
  debouncedUpdateFn?: (dispatch: AppDispatch) => void
  shouldRefreshCalendarListRef: React.MutableRefObject<boolean>
  currentDebouncePeriod?: number
} = {
  calendarsToRefresh: new Map<string, any>(),
  calendarsToHide: new Set(),
  shouldRefreshCalendarListRef: { current: false },
  currentDebouncePeriod: 0,
  debouncedUpdateFn: undefined
}

describe('websocket messages storm', () => {
  beforeEach(() => {
    ;(refreshCalendarWithSyncToken as unknown as jest.Mock).mockClear()
    jest.clearAllMocks()
    jest.clearAllTimers()
    jest.resetModules()
    ;(getDisplayedCalendarRange as jest.Mock).mockReturnValue(mockRange)
    ;(store.getState as jest.Mock).mockReturnValue(mockState)
    window.WS_DEBOUNCE_PERIOD_MS = 500
    window.WS_SKIP_DELAY_MS = 0
    mockAccumulators.calendarsToRefresh = new Map<string, any>()
    mockAccumulators.calendarsToHide = new Set()
    mockAccumulators.shouldRefreshCalendarListRef.current = false
    mockAccumulators.currentDebouncePeriod = 0

    mockAccumulators.debouncedUpdateFn = undefined
  })
  it('debounces calendar updates during message storm', () => {
    const mockMessage = {
      '/calendars/cal1/entry1': {
        syncToken: 'ldsk'
      }
    }

    for (let i = 0; i < 50; i++) {
      updateCalendars(mockMessage, mockDispatch, mockAccumulators)
    }

    // Dispatch called once because of leading edge
    expect(refreshCalendarWithSyncToken).toHaveBeenCalledTimes(1)

    // Trailing edge
    jest.advanceTimersByTime(500)

    // only one call for the last message + leading edge message
    expect(refreshCalendarWithSyncToken).toHaveBeenCalledTimes(2)
  })

  it('debounces calendar updates during message storm with multiple updates', () => {
    // Send a storm with mixed messages
    for (let i = 0; i < 50; i++) {
      if (i % 3 === 0)
        updateCalendars(
          { '/calendars/cal/A': { syncToken: 'ldskfjsld' + i } },
          mockDispatch,
          mockAccumulators
        )
      else if (i % 3 === 1)
        updateCalendars(
          { '/calendars/cal/B': { syncToken: 'ldskfjsld' + i } },
          mockDispatch,
          mockAccumulators
        )
      else
        updateCalendars(
          { '/calendars/cal/C': { syncToken: 'ldskfjsld' + i } },
          mockDispatch,
          mockAccumulators
        )
    }

    // Dispatch called once because of leading edge
    expect(refreshCalendarWithSyncToken).toHaveBeenCalledTimes(1)

    // Trailing edge
    jest.advanceTimersByTime(500)

    // Trailing edge updates once per calendar + the original leading edge
    expect(refreshCalendarWithSyncToken).toHaveBeenCalledTimes(4)
  })

  it('executes immediately when debounce is disabled', () => {
    window.WS_DEBOUNCE_PERIOD_MS = 0

    updateCalendars(
      { '/calendars/cal1/entry1': { syncToken: 'abc' } },
      mockDispatch,
      mockAccumulators
    )

    expect(refreshCalendarWithSyncToken).toHaveBeenCalledTimes(1)
  })
})