Jasmine：测试作为参数传入另一个方法的方法是否运行答案

【问题标题】：Jasmine: Testing that a method passed in as an argument to another method gets runJasmine：测试作为参数传入另一个方法的方法是否运行
【发布时间】：2021-09-16 19:22:52
【问题描述】：

我的代码如下

//agency_controller.js
import axios from 'axios';

export const getProducerNamesAndBillingPlan = ({ agencyId = '', onSuccess= (x) => x } = {} )  => {
  if(!!agencyId) {
    axios.get('/agency/' + agencyId)
         .then(response => onSuccess.call(this, response['data']))
         .catch(error => console.error(error))
  }
}

//agency_controller.spec.js
import { getProducerNamesAndBillingPlan } from "../../../../app/javascript/packs/controllers/agencies_controller";
import axios from 'axios';

const mockAxiosPromise = (response) => {
  return new Promise((resolve, _reject) => {
    resolve({ status: 200, data: response});
  });
}

describe('#getProducerNamesAndBillingPlan', () => {
...
it('calls the given onSuccess method if the request is successful', () => {
    spyOn(axios, 'get').and.callFake(() => {
      return mockAxiosPromise('foo')
    })

    const mockMethod = (x) => console.log(x)

    spyOn(console.log, 'call')

    getProducerNamesAndBillingPlan({ agencyId: 1, onSuccess: mockMethod })

    expect(console.log.call).toHaveBeenCalledWith('foo')
  })
})

我可以看出代码正在运行，因为当我运行测试时，'foo' 被记录到控制台。但是测试仍然失败：

#getProducerNamesAndBillingPlan calls the given onSucess method if the request is sucessful FAILED
        Expected spy call to have been called with [ 'foo' ] but it was never called.
            at UserContext.<anonymous> (spec/javascripts/packs/controllers/agencies_controller.spec.js:1:17348)

expect(console.log).toHaveBeenCalledWith('foo') 也是如此。我做错了吗？

【问题讨论】：

标签： javascript unit-testing axios jasmine karma-jasmine

【解决方案1】：

axios.get() 方法返回一个 promise，但 getProducerNamesAndBillingPlan 函数不返回它。您在测试用例中调用它。当代码执行expect语句时，promise没有被解析或拒绝，所以你的onSuccess方法在断言之前没有被调用。

在测试用例中使用async/await 以确保在断言之前已解决或拒绝承诺。

agency_controller.js:

import axios from 'axios';

export const getProducerNamesAndBillingPlan = ({ agencyId = '', onSuccess = (x) => x } = {}) => {
  if (!!agencyId) {
    return axios
      .get('/agency/' + agencyId)
      .then((response) => onSuccess.call(this, response['data']))
      .catch((error) => console.error(error));
  }
};

agency_controller.spec.js:

import axios from 'axios';
import { getProducerNamesAndBillingPlan } from './agency_controller';

describe('#getProducerNamesAndBillingPlan', () => {
  it('calls the given onSuccess method if the request is successful', async () => {
    spyOn(axios, 'get').and.resolveTo({ status: 200, data: 'foo' });
    const mockMethod = (x) => console.log(x);
    spyOn(console, 'log');
    await getProducerNamesAndBillingPlan({ agencyId: 1, onSuccess: mockMethod });
    expect(console.log).toHaveBeenCalledWith('foo');
  });
});

测试结果：

Executing 1 defined specs...
Running in random order... (seed: 00239)

Test Suites & Specs:

1. #getProducerNamesAndBillingPlan
   ✔ calls the given onSuccess method if the request is successful (5ms)

>> Done!


Summary:

?  Passed
Suites:  1 of 1
Specs:   1 of 1
Expects: 1 (0 failures)
Finished in 0.01 seconds

【讨论】：