当运行单元测试时，你不必须调用真实的的API调用。你必须封装你的组件并提供任何外部信息。
使用jest你可以mockhttp调用并返回你想要的结果。你还可以检查mock是否被调用过。

import { got } from "anyplace/got";
import { firstFunction } from "anyplace2";

jest.mock("anyplace/got", () => ({
 // here you provide a mock to any file that imports got to make http calls
 got: {
   // "mockResolvedValue" tells jest to return a promise resolved 
   // with the value provided inside. In this case {data: 'what you 
   // want here'}
   post: jest.fn().mockResolvedValue({data: 'what you want here'});
 }
}));

describe('My test', () => {
 beforeEach(() => {
  // This will clear all calls to your mocks. So for every test you will 
  // have your mocks reset to zero calls
  jest.clearAllMocks();
 });

 it('Should call the API call successfully', () => {
  // execute the real method
  firstFunction({arg: 1});

  // check that the API has been called 1 time
  expect(got.post).toHaveBeenCalledTimes(1);
  expect(got.post).toHaveBeenCalledwith("myurlhere", {data: {arg: 1}});
 })
});

您可以使用setTimeout来模拟它，我还提供了一个模拟响应，因此在1000ms后，它将发送一个带有此用户数组的Promise

const getData = () => {
    return new Promise((resolve, reject) => {
        setTimeout(resolve({
            users: [
                { name: "Michael" },
                { name: "Sarah" },
                { name: "Bill" },
            ]
        }), 1000)
    })
}