錯誤：在帶有nock和模擬存儲的Redux應用程序中的異步操作測試中，操作可能未定義

Question

有點難過這一件事。 按照Redux文檔為我的異步操作（ docs此處 ）設置測試后，出現錯誤：

動作可能不是未定義的。 （在調度時（node_modules / redux-mock-store / lib / index.js：35：19））

測試此操作：

export const FETCH_TRANSACTIONS = 'FETCH_TRANSACTIONS'

function fetchTransactionsSuccess (transactions) {
  return {
    type: FETCH_TRANSACTIONS,
    payload: transactions
  }
}

export const fetchTransactions = () => dispatch => axios.get('/api/transactions')
  .then(transactions => dispatch(fetchTransactionsSuccess(transactions)))
  .catch(err => dispatch(handleErr(err)))

這就是測試本身。 任何幫助都將是驚人的。 凝視了這么久，我的眼睛受傷了。

import configureMockStore from 'redux-mock-store'
import thunk from 'redux-thunk'
import * as actions from '../../client/actions/actionCreators'
import nock from 'nock'
import expect from 'expect'

const middlewares = [ thunk ]
const mockStore = configureMockStore(middlewares)

describe('async actions', () => {
  afterEach(() => {
    nock.cleanAll()
  })

  it('dispatches FETCH_TRANSACTIONS when data is returned', () => {
    nock('http://localhost:3000/')
      .get('/api/transactions')
      .reply(200, [
        {
          "_id": "588900efdf9d3e0905a2d604",
          "amount": 4.50,
          "name": "Cashew Nuts",
          "__v": 0,
          "date": "2017-01-25T00:00:00.000Z",
          "user": "58c2a33cc6cd5a5d15a8fc0c"
        },
        {
          "_id": "58890108df9d3e0905a2d605",
          "amount": 6.25,
          "name": "Monmouth Coffee",
          "__v": 0,
          "date": "2017-01-25T00:00:00.000Z",
          "user": "58c2a33cc6cd5a5d15a8fc0c"
        }
      ])

    const expectedActions = [
      {
        type: actions.FETCH_TRANSACTIONS,
        payload: [
          {
            "_id": "588900efdf9d3e0905a2d604",
            "amount": 4.50,
            "name": "Cashew Nuts",
            "__v": 0,
            "date": "2017-01-25T00:00:00.000Z",
            "user": "58c2a33cc6cd5a5d15a8fc0c"
          },
          {
            "_id": "58890108df9d3e0905a2d605",
            "amount": 6.25,
            "name": "Monmouth Coffee",
            "__v": 0,
            "date": "2017-01-25T00:00:00.000Z",
            "user": "58c2a33cc6cd5a5d15a8fc0c"
          }
        ]
      }
    ]

    const store = mockStore({ transactions: [] })
    console.log(actions)
    return store.dispatch(actions.fetchTransactions())
      .then(() => {
        expect(store.getActions()).toEqual(expectedActions)
      })
  })
})

更新handleErr函數返回setCurrentUser，這是另一個動作（原始動作通過dispatch調用：

export function handleErr (err) {
  if (err.status === 401 || err.status === 404) {
    localStorage.removeItem('mm-jwtToken')
    setAuthToken(false)
    return setCurrentUser({})
  }
}

Answer 1

使用nock axios請求存在一個已知問題 。 因此，我相信您的fetchTransactions動作創建者中的promise鏈屬於catch子句。 請檢查您的handleErr函數，它是否返回有效的Action？ 我敢打賭它返回undefined ，這就是為什么您有此錯誤消息。