import fetch, { Response } from 'node-fetch';

jest.mock('node-fetch');

describe('fetch-mock test', () => {
    const mockFetch = fetch as jest.MockedFunction<typeof fetch>;

    it('check fetch mock test', async () => {
      const json = jest.fn() as jest.MockedFunction<any>;
      json.mockResolvedValue({ status: 200}); //just sample expected json return value
      mockFetch.mockResolvedValue({ ok: true, json } as Response); //just sample expected fetch response
      await makeRequest();
      expect(json.mock.calls.length).toBe(1);
    })
})

我发现在Jest中模拟ECMAScript模块最简单的方法是使用jest.unstable_mockModule。
示例：

jest.unstable_mockModule("node-fetch", () => ({
  default: (url) => {
    if (url.includes("/groups/")) {
      return {
        ok: true,
        json: () => ({
          id: dummyGuid,
          name: "dummyStringForName",
          embedUrl: "https://example.com",
          datasetId: dummyGuid,
        }),
      }
    }
    if (url.endsWith("/GenerateToken")) {
      return {
        ok: true,
        json: () => ({
          token: "dummyStringForToken",
        }),
      }
    }
  },
}))

您可以使用jest.mock模拟node-fetch，然后在测试集中模拟实际响应

import fetch from 'node-fetch'
jest.mock('node-fetch', ()=>jest.fn())

describe('fetch-mock test', () => {
    it('check fetch mock test', async () => {

        var makeRequest = require('../mock/makeRequest');

         const response = Promise.resolve({
                ok: true,
                status,
                json: () => {
                    return returnBody ? returnBody : {};
                },
               })
        fetch.mockImplementation(()=> response)
        await response
        makeRequest().then(function (data) {
            console.log('got data', data);
        }).catch((e) => {
            console.log(e.message)
        });

    });
});