1 import { Test, TestingModule } from '@nestjs/testing';
 2 import { AppController } from './app.controller';
 3 import { AppService } from './app.service';
 4 import { ApplicationModule } from './app.module';
 5 import { Request } from 'jest-express/lib/request';
 6 import { Response } from 'jest-express/lib/response';
 7 
 8 describe('AppController', () => {
 9     let appController: AppController, appService: AppService, req: Request, res: Response;
10 
11     beforeAll(async () => {
12         const module: TestingModule = await Test.createTestingModule({
13             imports: [ApplicationModule],
14         }).compile();
15 
16         appController = module.get<AppController>(AppController);
17         appService = module.get<AppService>(AppService);
18         req = new Request();
19         res = new Response();
20     });
21 
22     describe('controller test', () => {
23         it('Mock一个函数返回动态测试数据', () => {
24             expect.assertions(1);
25 
26             // 通过jest.fn()来Mock一个回调函数返回测试数据
27             const mockfn = jest.fn();
28             const result = mockfn.mockReturnValue(`[${new Date()}]: Welcome to use youtu test service.`);
29 
30             // 调用Controller的root方法，root方法调用service里的root方法返回相应的结果与mock结果是否达到预期
31             expect(appController.root()).toBe(result());
32         });
33 
34         it('监听函数是否被正常调用', async (done) => {
35             // 验证第二个断言被调用，测试异步代码时这通常很有用
36             expect.assertions(3);
37             const spyfn = jest.spyOn(appService, 'getAllUsers');
38             req.setBody({ name: 'mock data' });
39             expect(await appController.getAllUsers(req, res)).toBe('test service');
40             // 用来判断一个函数是否被调用过
41             expect(spyfn).toHaveBeenCalled();
42 
43             // 判断函数被调用过几次
44             expect(spyfn).toHaveBeenCalledTimes(1);
45             done();
46         });
47 
48         it('Mock函数调用', async (done) => {
49             // 验证第二个断言被调用，测试异步代码时这通常很有用
50             expect.assertions(3);
51             const resultMock = Promise.resolve('test mock');
52 
53             // 监听并Mock掉appService.getAllUsers函数的返回结果，当这个函数有依赖第三方的时候可以使用
54             const spyfn = jest.spyOn(appService, 'getAllUsers').mockImplementation(() => resultMock);
55             expect(await appController.getAllUsers(req, res)).toBe('test mock');
56 
57             // 用来判断一个函数是否被调用过
58             expect(spyfn).toHaveBeenCalled();
59 
60             // 判断函数被调用过几次
61             expect(spyfn).toHaveBeenCalledTimes(2);
62             done();
63         });
64 
65         it('promise throws', async (done) => {
66             expect.assertions(1);
67             const message = 'test service error';
68             const result2 = Promise.reject(new Error(message));
69 
70             // 劫持getAllUsers函数并返回一个异常给appController
71             jest.spyOn(appService, 'getAllUsers').mockImplementation(() => result2);
72             await expect(appController.getAllUsers(req, res)).rejects.toThrow(message);
73             done();
74         });
75     });
76 });

 1 {
 2     // 使用 IntelliSense 了解相关属性。
 3     // 悬停以查看现有属性的描述。
 4     // 欲了解更多信息，请访问: https://go.microsoft.com/fwlink/?linkid=830387
 5     "version": "0.2.0",
 6     "configurations": [
 7         {
 8             "name": "Debug TypeScript",
 9             "type": "node",
10             "request": "launch",
11             "env": {
12                 "NODE_ENV": "development"
13             },
14             "runtimeExecutable": "nodemon",
15             "restart": true,
16             "args": [
17                 "${workspaceRoot}/src/main.ts"
18             ],
19             "runtimeArgs": [
20                 "--config",
21                 " nodemon-debug.json",
22                 "--nolazy",
23                 "-r",
24                 "ts-node/register"
25             ],
26             "sourceMaps": true,
27             "disableOptimisticBPs": true,
28             "cwd": "${workspaceRoot}",
29             "protocol": "inspector",
30             "console": "integratedTerminal",
31             "internalConsoleOptions": "neverOpen"
32         },
33         {
34             "type": "node",
35             "request": "launch",
36             "name": "Debug Jest Tests",
37             "program": "${workspaceFolder}/node_modules/.bin/jest",
38             "args": [
39                 "-r tsconfig-paths/register",
40                 "-r ts-node/register",
41                 "--runInBand"
42             ],
43             "console": "integratedTerminal",
44             "internalConsoleOptions": "neverOpen",
45             "disableOptimisticBPs": true,
46             "skipFiles": [
47                 "<node_internals>/**"
48             ],
49         },
50         {
51             "type": "node",
52             "request": "launch",
53             "name": "Debug Jest File",
54             "program": "${workspaceFolder}/node_modules/.bin/jest",
55             "args": [
56                 "${fileBasenameNoExtension}",
57                 "-r tsconfig-paths/register",
58                 "-r ts-node/register",
59                 "--runInBand"
60             ],
61             "console": "integratedTerminal",
62             "internalConsoleOptions": "neverOpen",
63             "disableOptimisticBPs": true,
64         },
65     ]
66 }