Creating Node.JS web server application with Express, Typescript, Jest, Swagger, log4js and routing-controllers

Install in right order Node.JS, packages and configure them.

1) node.js download,  2) Create directory for your project,  3) npm init,  4) in package.json  "main": "dist/index.js",   "scripts": {     "build": "tsc",     "start": "node ."   } 5) npm install --save-dev typescript,  6) in tsconfig.json    {   "compilerOptions": {     "esModuleInterop": true,     "outDir": "dist",     "baseUrl": "."   } } 8) npm install express,  9) npm install @types/express,  10) create src folder,  11) create src/index.ts with code below: import express from 'express'  const app = express(); const port = 5000; app.get('/', (request, response) => {   response.send('Hello world!'); }); app.listen(port, () => console.log(`Running on port ${port}`)); 13) npm run build,  14) npm run start,  15) localhost:5000 

Set up debug mode and create an .env file to set input values.

1) in tsconfig.json add: "sourceMap": true 2) int package.json add: "prestart": "npm run build", 3) In IntelliJ IDEA in Run/Debug Configurations choose: "npm" and add script 4) npm i ts-node-dev --save-dev 5) int package.json add: "server:watch": "ts-node-dev --respawn --transpile-only src/index.ts" 6) add IntelliJ IDEA npm for "server:watch" script 7) npm install dotenv 8) in index.ts add: dotenv.config(); 9) create .env file in root dir of your project and add text below in .env file: PORT = 5000 const port = process.env.PORT; 

1) npm install log4js 2) in index.ts file:     import log4js from 'log4js';     ...     const logger = log4js.getLogger();     logger.level = process.env.LOG_LEVEL;     ... 4) in .env file: LOG_LEVEL=error 5) in index.ts file:     ...     logger.info('log4js log info');     logger.debug('log4js log debug');     logger.error('log4js log error');     ... 6) npm install eslint --save-dev 7) eslint --init 8) "prebuild": "npm run lint" 9) "lint:fix": "eslint --cache --ext .ts . --fix", 10) "lint": "eslint --cache --ext .ts .",     !!! --cache (only changed), . 11) IntelliJ IDEA -- file -- setting -- eslint -- automatic 12) "rules": {         "semi": ["error", "always"]     } 

Use routing-controllers for more convenient work.

1) npm install routing-controllers 2) npm install reflect-metadata 3) npm install express body-parser multer 4) npm install class-transformer class-validator 5) tsconfig.json    "compilerOptions": {       ...       "emitDecoratorMetadata": true,       "experimentalDecorators": true       ...    } 6) in index.ts // const app = express();  // logger.info('log4js log info'); // logger.debug('log4js log debug'); // logger.error('log4js log error');  // app.get('/', (request, response) => { //   response.send('Hello world2!'); // }); 7) in index.ts    import { createExpressServer } from 'routing-controllers';    import { UserController } from './UserController';     const app = createExpressServer({      controllers: [UserController], // we specify controllers we want to use });  8) controller/user-controller.ts    import { Controller, Get, Param } from 'routing-controllers';    import 'reflect-metadata';     @Controller()    export class UserController {      @Get('/users/:id')      getOne (@Param('id') id: number) {        return 'This action returns user #' + id;      }    } 9) http://localhost:3001/users/1 

1) middleware -- middleware.ts 2) middleware.ts export function loggingBefore (request: any, response: any, next?: (err?: any) => any): any {   console.log('do something Before...');   next(); }  export function loggingAfter (request: any, response: any, next?: (err?: any) => any): any {   console.log('do something After...');   next(); } 3) user-controller.ts in class @UseBefore(loggingBefore) @UseAfter(loggingAfter) console.log('do something in GET function...'); 4) user-controller.ts in function  @UseBefore(loggingBefore)  @UseAfter(loggingAfter) 5) user-controller.ts in function  @UseInterceptor(function (action: Action, content: any) {     console.log('change response...');     return content;   }) 6) npm install express-http-context 7) index.ts    const app: Express = express();         app.use(bodyParser.json());  app.use(httpContext.middleware);  useExpressServer(app, {    controllers: [UserController]  });   app.use((req, res, next) => {    httpContext.ns.bindEmitter(req);    httpContext.ns.bindEmitter(res);  });  8) middleware.ts loggingBefore     import httpContext from 'express-http-context';          console.log('set traceId = 123');     httpContext.set('traceId', 123); 9) middleware.ts loggingAfter     console.log(`tracedId = ${httpContext.get('traceId')}`); 

1) in user-controller.ts add:   ...   @Post('/users/:id')   @OnUndefined(204)   postOne (@Param('id') id: number, @Body() info: any) {     console.log(JSON.stringify(info));   }   ... 2) in postman  http://localhost:3001/users/1  {  "country":"Russia",  "city":"SPb"  } 3) model -- info.ts 4)  import { IsDefined } from 'class-validator';  export class Info {   @IsDefined()   country: string;   @IsDefined()   city: string; } 8) postOne (@Param('id') id: number, @Body() info: Info) { 9) middleware -- global-error-handler.ts 10)  import { ExpressErrorMiddlewareInterface, Middleware } from 'routing-controllers';  @Middleware({ type: 'after' }) export class GlobalErrorHandler implements ExpressErrorMiddlewareInterface {   error (error: any, request: any, response: any, next: () => any) {     response.send({ ERROR: error });     next();   } } 11)  useExpressServer(app, {   controllers: [UserController], // we specify controllers we want to use   middlewares: [GlobalErrorHandler],   defaultErrorHandler: false }); 

1) npm install swagger-ui-express 2) tsconfig.json -- "resolveJsonModule": true 3) src -- swagger -- openapi.json 4) index.ts import swaggerUi from 'swagger-ui-express'; import * as swaggerDocument from '../src/swagger/openapi.json'; ... app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument)); 5) change port to 3000 in .env file set PORT=3000 6) npm install cors 7) npm install @types/cors 8) in index.ts  import cors from 'cors'; ... app.use(cors() as RequestHandler); ... 9) Swagger Editor (example for test project)  openapi  openapi: 3.0.1 info:   title: test API   version: v1 servers:   - url: 'http://localhost:3000' tags:   - name: API functions     description: >-       API functions of our application        paths:   /users/{id}:     get:      summary: returns simple answer from get      tags:        - API functions      parameters:        - name: id          in: path          required: true          description: simple parameter          schema:            type : string            example: '1'      description: parameter id just for test      responses:       '200': #status code        description: OK        content:             document:               schema:                 type: string                 example: some text     post:      summary: returns simple answer from post      tags:        - API functions      requestBody:         required: true         content:           application/json:             schema:                $ref: '#/components/schemas/Info'                       example:               country: Russia               city: Spb      parameters:        - name: id          in: path          required: true          description: simple parameter          schema:            type : string            example: '1'      description: parameter id just for test      responses:       '204': #status code        description: OK components:   schemas:     Info:       type: object       properties:         country:           type: string         city:             type: string 

0) in global-error-handler.ts response.status(error.statusCode || error.httpCode).json(error);     next();  1) npm install --save-dev jest 2) npm i -D ts-jest @types/jest 3) npm i -D ts-jest 4) package.json --  { ... scripts { ... "test:unit": "jest --config=jest.config.js", }, ... } 5) create jest.config.js with code below:  process.env.NODE_ENV = 'UNITTEST'; module.exports = {     clearMocks: true,     collectCoverage: true,     collectCoverageFrom: [         './src/**/*.ts'     ],     coverageDirectory: '<'rootDir>/test/coverage',     testEnvironment: 'node',     testMatch: ['**/*.test.ts'],     preset: 'ts-jest' };  6) .eslintignore *.js node_modules dist coverage } 7) .eslintrc.json { ... "env": {    "jest": true }  ... }  8) test -- controller -- user-controller.test.ts  describe('UserController', () => {   afterEach(() => {     jest.restoreAllMocks();   });    it('postOne', () => {     const userController = new UserController();     const testBody = {       city: 'SPb'     };     const res = userController.postOne(1, testBody as Info);     expect(res).toBeUndefined();   }); }  9) in IDEA add script - test:unit set in environment - NODE_ENV=UNITTEST 10) Simple variant of jest.config.js for IDEA: process.env.NODE_ENV = 'UNITTEST'; module.exports = {   clearMocks: true,   collectCoverage: false,   testEnvironment: 'node',   testMatch: ['**/*.test.ts'],   preset: 'ts-jest' }; 11) npm i -D supertest @types/supertest 12) in user-controller.test.ts ... let server; ... beforeAll(async () => {     server = express();     server.use(bodyParser.json());     useExpressServer(server, {       controllers: [UserController], // we specify controllers we want to use       middlewares: [GlobalErrorHandler],       defaultErrorHandler: false     });   }); ... it('postOne with validations', done => {     request(server)       .post('/users/1')       .send({         country: 'Russia',         city: 'SPb'       } as Info)       .expect(204)       .end((err, res) => {         if (err) throw new Error(JSON.stringify(res.body));         done();       });   }); 

Config package allows to set value for constants depending on NODE_ENV value.

1) npm install config 2) npm install @types/config 3) config 4) default.yaml PORT: 3000     DEV.yaml PORT: 3001     LOCAL.yaml PORT: 3002  5) index.ts    // const port = process.env.PORT;       const port = config.get('PORT'); 6) IDEA server:watch -- Environment     NODE_ENV=DEV     NODE_ENV=LOCAL  -- packages:  husky - commits in Git semantic-release - Commits formatting and version control  pretty-quick - run prettier for changed files prettier - code formtatter eslint-config-prettier - resolve conflicts between eslint and prettier eslint-plugin-prettier - run prettier as eslint rules  mock-socket - websocket mock jest-websocket-mock - websocket testing jest-sonar-reporter - convert reports from jest format to sonar format jest-mock-extended - mocks for objects and interfaces  ws - websocket  typescript-string-operations - String.format lodash - useful functions for js http-status-codes - constants for HTTP statuses moment - time library for js  ncp - copy files js-yaml - working with yaml files  mongodb - package with functions for Mongo migrate-mongo - migration for Mongo  log-timestamp - write current time in log messages  axios - HTTP client  applicationinsights - integration with Azure Application Insights