用vscode进行jest单元测试并调试代码

首先需要安装相应的包：npm i -D jest ts-jest supertest jest-express jest-sonar-reporter sonarqube-scanner

1、单元测试：npm run test

2、代码覆盖率：npm run test:cov

3、使用SonarQube平台分析：npm run sonar，完成后就可以使用SonarQube web查看相关数据

4、如何调试单元测试的代码，有二种方法：1、在vscode终端运行npm run test:debug，2、在vscode的launch.json中添加相应的代码，然后就右直接选择运行中的Debug Jest Tests来启动

在pageage.json增加如下配置

"scripts": {
    "lint": "eslint 'src/**/*.{ts,js}'",
    "lint:fix": "eslint 'src/**/*.{ts,js}' --fix",
    "lint:ts": "tslint -p tsconfig.json -c tslint.json",
    "test": "jest --runInBand --forceExit --colors",
    "test:watch": "jest --watch",
    "test:cov": "jest --coverage",
    "test:debug": "node --inspect-brk -r tsconfig-paths/register -r ts-node/register node_modules/.bin/jest --runInBand",
    "test:e2e": "jest --runInBand --config ./test/jest-e2e.json",
    "sonar": "node sonar-project.js"
  },
"engines": {
    "node": ">=8.9.0"
  },
  "jest": {
    "moduleFileExtensions": [
      "js",
      "json",
      "ts"
    ],
    "moduleNameMapper": {
      "^@creative(.*)$": "<rootDir>/modules/creative$1",
      "^@admin(.*)$": "<rootDir>/modules/admin$1",
      "^@configuration(.*)$": "<rootDir>/modules/configuration$1",
      "^@common(.*)$": "<rootDir>/common$1",
      "^@auth(.*)$": "<rootDir>/modules/auth$1"
    },
    "rootDir": "src",
    "testRegex": ".spec.ts$",
    "transform": {
      "^.+\.(t|j)s$": "ts-jest"
    },
    "collectCoverageFrom": [
      "**/*.(t|j)s"
    ],
    "testResultsProcessor": "jest-sonar-reporter",
    "coverageDirectory": "../coverage",
    "coveragePathIgnorePatterns": [
      "/node_modules/"
    ],
    "testEnvironment": "node"
  },
  "jestSonar": {
    "reportPath": "coverage",
    "reportFile": "test-reporter.xml",
    "indent": 4
  }

sonar-project.js

const sonarqubeScanner = require('sonarqube-scanner');
const parameters = {
    serverUrl:  'http://localhost:9000',
    token: 'XXX',
    options : {
        'sonar.projectVersion': '1.1',
        'sonar.projectName': 'create-server',
        'sonar.projectKey': 'create-server',
        'sonar.sourceEncoding': 'UTF-8',
        'sonar.scm.provider': 'git',
        'sonar.language': 'typescript',
        'sonar.sources': 'src',
        'sonar.inclusions': 'src/**',
        'sonar.exclusions': '**/node_modules/**,**/coverage/**',
        'sonar.tests': 'test',
        'sonar.ts.tslint.configPath': 'tslint.json',
        'sonar.test.inclusions': 'src/**/*.spec.ts,test/**/*.e2e-spec.ts',
        'sonar.testExecutionReportPaths':  'coverage/test-reporter.xml',
        'sonar.javascript.lcov.reportPaths': 'coverage/lcov.info',
    }
}
sonarqubeScanner(parameters, () => process.exit());

示例代码　　

import { Test, TestingModule } from '@nestjs/testing';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { ApplicationModule } from './app.module';
import { Request } from 'jest-express/lib/request';
import { Response } from 'jest-express/lib/response';

describe('AppController', () => {
    let appController: AppController, appService: AppService, req: Request, res: Response;

    beforeAll(async () => {
        const module: TestingModule = await Test.createTestingModule({
            imports: [ApplicationModule],
        }).compile();

        appController = module.get<AppController>(AppController);
        appService = module.get<AppService>(AppService);
        req = new Request();
        res = new Response();
    });

    describe('controller test', () => {
        it('Mock一个函数返回动态测试数据', () => {
            expect.assertions(1);

            // 通过jest.fn()来Mock一个回调函数返回测试数据
            const mockfn = jest.fn();
            const result = mockfn.mockReturnValue(`[${new Date()}]: Welcome to use youtu test service.`);

            // 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
            expect(appController.root()).toBe(result());
        });

        it('监听函数是否被正常调用', async (done) => {
            // 验证第二个断言被调用，测试异步代码时这通常很有用
            expect.assertions(3);
            const spyfn = jest.spyOn(appService, 'getAllUsers');
            req.setBody({ name: 'mock data' });
            expect(await appController.getAllUsers(req, res)).toBe('test service');
            // 用来判断一个函数是否被调用过
            expect(spyfn).toHaveBeenCalled();

            // 判断函数被调用过几次
            expect(spyfn).toHaveBeenCalledTimes(1);
            done();
        });

        it('Mock函数调用', async (done) => {
            // 验证第二个断言被调用，测试异步代码时这通常很有用
            expect.assertions(3);
            const resultMock = Promise.resolve('test mock');

            // 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
            const spyfn = jest.spyOn(appService, 'getAllUsers').mockImplementation(() => resultMock);
            expect(await appController.getAllUsers(req, res)).toBe('test mock');

            // 用来判断一个函数是否被调用过
            expect(spyfn).toHaveBeenCalled();

            // 判断函数被调用过几次
            expect(spyfn).toHaveBeenCalledTimes(2);
            done();
        });

        it('promise throws', async (done) => {
            expect.assertions(1);
            const message = 'test service error';
            const result2 = Promise.reject(new Error(message));

            // 劫持getAllUsers函数并返回一个异常给appController
            jest.spyOn(appService, 'getAllUsers').mockImplementation(() => result2);
            await expect(appController.getAllUsers(req, res)).rejects.toThrow(message);
            done();
        });
    });
});

配置vscode调试

{
    // 使用 IntelliSense 了解相关属性。
    // 悬停以查看现有属性的描述。
    // 欲了解更多信息，请访问: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Debug TypeScript",
            "type": "node",
            "request": "launch",
            "env": {
                "NODE_ENV": "development"
            },
            "runtimeExecutable": "nodemon",
            "restart": true,
            "args": [
                "${workspaceRoot}/src/main.ts"
            ],
            "runtimeArgs": [
                "--config",
                " nodemon-debug.json",
                "--nolazy",
                "-r",
                "ts-node/register"
            ],
            "sourceMaps": true,
            "disableOptimisticBPs": true,
            "cwd": "${workspaceRoot}",
            "protocol": "inspector",
            "console": "integratedTerminal",
            "internalConsoleOptions": "neverOpen"
        },
        {
            "type": "node",
            "request": "launch",
            "name": "Debug Jest Tests",
            "program": "${workspaceFolder}/node_modules/.bin/jest",
            "args": [
                "-r tsconfig-paths/register",
                "-r ts-node/register",
                "--runInBand"
            ],
            "console": "integratedTerminal",
            "internalConsoleOptions": "neverOpen",
            "disableOptimisticBPs": true,
            "skipFiles": [
                "<node_internals>/**"
            ],
        },
        {
            "type": "node",
            "request": "launch",
            "name": "Debug Jest File",
            "program": "${workspaceFolder}/node_modules/.bin/jest",
            "args": [
                "${fileBasenameNoExtension}",
                "-r tsconfig-paths/register",
                "-r ts-node/register",
                "--runInBand"
            ],
            "console": "integratedTerminal",
            "internalConsoleOptions": "neverOpen",
            "disableOptimisticBPs": true,
        },
    ]
}