如何在JEST中模拟带有配置的API调用？

Question

我的应用程序接口使用的是@woocommerce/woocommerce-rest-api包。我正在使用NextJS和React Redux。这是我的woocommerce配置：

import WooCommerceRestApi from '@woocommerce/woocommerce-rest-api';

export const wooApi = new WooCommerceRestApi({
   url: 'MY_API_URL',
   consumerKey: 'MY_CONSUMER_KEY',
   consumerSecret: 'MY_CONSUMER_SECRET',
   version: 'wc/v3',
   queryStringAuth: true,
});

当组件挂载时，我立即调度一个操作。

下面是我在操作中如何使用API：

export const fetchMainProductCategories = () => {
    return async (dispatch: Dispatch) => {
       try {
          const response = await wooApi.get(`products/categories?hide_empty=true&parent=0`);
          dispatch<FetchMainProductCategories>({
             type: CategoryTypes.fetchMainProductCategories,
             payload: response.data,
        });

        } catch (error) {
             console.log(error);
        }
      };
   };

以下是到目前为止我的初始测试语句，但我不能工作：

import React from 'react';
import '../../__mocks__/matchMedia';
import MockCategories from '../../__mocks__/mockCategories';
import { render, cleanup, logDOM } from '@testing-library/react';
import Index from '../../pages/index';
import Root from '../../Root';
import { wooApi } from '../../config';

jest.mock('../../config');

describe('Homepage', () => {
   beforeEach(() => {
      render(
        <Root>
          <Index />
       </Root>
    );
 });

 afterEach(cleanup);

 it('loads Product Categories', async () => {
       wooApi.get.mockResolvedValueOnce({
          data: MockCategories,
       });
       logDOM();
    // const list = await waitFor(() => screen.getByTestId('category-list'));
    });
 });

Answer 1

您需要将wooApi的get方法注册为模拟，同时保留api的其他特性。即：

import { wooApi } from '../../config'
import { fetchMainProductCategories } from '../where-it-is-defined'

// mark get method as jest mock
jest.mock('../../config', () => ({
   ...jest.requireActual('../../config'), // to avoid overriding other methods/features
   get: jest.fn(), // override get method of the api
}))

describe('Homepage', () => {
   beforeEach(()=>{
      wooApi.get.mockResolvedValue({
         status: 200,
         data: { categories: ['a', 'b'] },
   })

   test('loads ...', async () => {
   const dispatch = jest.fn()

   await fetchMainProductCategories()(dispatch)

   expect(dispatch).toHaveBeenCalledWith(
      { type: '...',
        payload: { categories: ['a', 'b'] }
      }
    )
   })
})

参考文献： Bypassing Module Mocks in Jest

Answer 2

get编辑：我的错，通过做jest.spyOn(config.wooApi, 'get')，我们只是在模仿单个实例的“”方法。以下编辑过的代码应该可以工作

您还可以使用jest.spyOn仅模拟get方法，如下所示

import * as config from '../../config'

jest.spyOn(WooCommerceRestApi.prototype, 'get')
WooCommerceRestApi.prototype.get.mockResolvedValue('...')