allbot/core/db.test.ts

import { createDB } from './db.js'
import * as redis from 'redis'
import { anyFunction, mock } from 'jest-mock-extended'

describe('db', () => {
  describe('#createDB', () => {
    test('should throw error if not uri passed', async () => {
      await expect(async () => {
        await createDB(undefined)
      }).rejects.toThrow()
    })

    test('should return correct redis client', async () => {
      const clientMock = mock<Awaited<ReturnType<typeof createDB>>>()
      const mockFn = jest
        .spyOn(redis, 'createClient')
        .mockReturnValue(clientMock)

      const uri = 'asd'
      const client = await createDB(uri)

      expect(mockFn).toBeCalledWith({ url: uri })
      expect(client).toEqual(clientMock)
      expect(client.connect).toBeCalledTimes(1)
    })

    test('should handle redis client error and reconnect', async () => {
      const handler = jest.fn()
      const clientMock = mock<Awaited<ReturnType<typeof createDB>>>({
        on: handler,
        isOpen: false,
      })
      clientMock.connect.mockResolvedValue()
      jest.spyOn(redis, 'createClient').mockReturnValue(clientMock)
      handler.mockImplementation((_, errorHandler) => {
        errorHandler('testError')
      })

      const uri = 'asd'
      const client = await createDB(uri)

      expect(client).toEqual(clientMock)
      expect(handler).toBeCalledWith('error', anyFunction())
      expect(client.connect).toBeCalledTimes(2)
    })
  })
})