redux-saga 的单元测试抛出错误：必须在迭代器上调用 runSaga

Posted 2023-02-22

【中文标题】redux-saga 的单元测试抛出错误：必须在迭代器上调用 runSaga

【英文标题】：Unit-test of redux-saga throws error: runSaga must be called on an iterator

【发布时间】：2018-08-23 22:56:51

【问题描述】：

在使用 React 和 redux 进行编码以及使用 JEST、酶和 sinon 进行测试时，我非常熟悉，所以请耐心等待。

我正在尝试在我的应用程序中测试 saga。目前我正在尝试测试我的“serverSaga”，它负责调用 REST-API 并将状态设置为响应的内容（在本例中为食物菜单）。

当我尝试运行测试时，它失败并出现错误：

runSaga must be called on an iterator

  20 | describe('Menu View Saga', () => 
  21 |   it('can retrieve todays menu', async () => 
> 22 |     await runSaga(
  23 |       
  24 |         dispatch: action => dispatched.push(action),
  25 |         getState: () => ()

我猜这与它无法从 serverSaga 迭代 handleRequest() 中的 yield 有关，但我有点不知道为什么会这样，以及我做错了什么。

测试：

 import sinon from "sinon";
import * as obj from "../../services/serverService";
import  handleRequest  from '../../sagas/serverSaga'
import  runSaga  from "redux-saga";
import  menuList  from '../../stubs/menuList'
import  setMenu  from '../../reducers/menuReducer'


const serverStub = sinon.stub(obj, 'callServerApi')

 serverStub.callsFake(() => 
  return 
    ...menuList.menu
  
)

const saga = handleRequest
const dispatched = 

describe('Menu View Saga', () => 
  it('can retrieve todays menu', async () => 
    await runSaga(
      
        dispatch: action => dispatched.push(action),
        getState: () => ()
      ,
        saga,
        'test-url',
        'GET'
    ).done

    expect(serverStub.calledOnce).toBeTruthy()
    expect(dispatched).toContainEqual(setMenu(menuList))

  )
)  

服务器传奇

import React,  Component  from 'react'
import  put, call, take, fork, select  from 'redux-saga/effects'
import  callServerApi  from '../services/serverService'


export function* handleRequest(url, method, data)

  //TODO - ERROR HANDLING

  return yield executeRequest(url, method, data)


function* executeRequest(url, method, data) 


   try  
    let response = yield call(callServerApi, url, method, data)
    let responseSuccess = response && response.Succeeded   

    //temporary workaround - should NOT return response here,
    return response



if (responseSuccess) 

  yield success(response)
  //return response

 else 
  console.log('ERROR', response)

  //TODO - ERROR HANDLING

    catch (error)
   console.log('Error from serverSaga', error)
//TODO - ERROR HANDLING
   

【参考方案1】：

阅读https://www.npmjs.com/package/redux-saga 上的文档后，我意识到我使用的是“非常旧”版本的 redux-saga (0.10.4)。升级到当前版本的 0.16.0 后，它会按预期工作，并且错误不再存在。