docs: update listen to use port env variable

.prettierrc

@@ -1,4 +1,5 @@
 {
   "singleQuote": true,
-  "trailingComma": "all"
+  "trailingComma": "all",
+  "printWidth": 80
 }

content/devtools/ci-cd.md

@@ -40,7 +40,7 @@ async function bootstrap() {
 
     await app.close();
   } else {
-    await app.listen(3000);
+    await app.listen(process.env.PORT ?? 3000);
   }
 }
 ```
@@ -232,9 +232,7 @@ const publishOptions = {
   sha: process.env.CI_COMMIT_SHA,
   target: process.env.CI_MERGE_REQUEST_DIFF_BASE_SHA,
   trigger: process.env.CI_MERGE_REQUEST_DIFF_BASE_SHA ? 'pull' : 'push',
-  branch:
-    process.env.CI_COMMIT_BRANCH ??
-    process.env.CI_MERGE_REQUEST_SOURCE_BRANCH_NAME,
+  branch: process.env.CI_COMMIT_BRANCH ?? process.env.CI_MERGE_REQUEST_SOURCE_BRANCH_NAME,
 };
 ```
 

content/devtools/overview.md

@@ -9,7 +9,7 @@ async function bootstrap() {
   const app = await NestFactory.create(AppModule, {
     snapshot: true,
   });
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 ```
 
@@ -185,7 +185,7 @@ This page comes in handy when you want to identify potential issues in your appl
 To save a serialized graph to a file, use the following code:
 
 ```typescript
-await app.listen(3000); // OR await app.init()
+await app.listen(process.env.PORT ?? 3000); // OR await app.init()
 fs.writeFileSync('./graph.json', app.get(SerializedGraph).toString());
 ```
 

content/exception-filters.md

@@ -141,7 +141,10 @@ Nest provides a set of standard exceptions that inherit from the base `HttpExcep
 All the built-in exceptions can also provide both an error `cause` and an error description using the `options` parameter:
 
 ```typescript
-throw new BadRequestException('Something bad happened', { cause: new Error(), description: 'Some error description' })
+throw new BadRequestException('Something bad happened', {
+  cause: new Error(),
+  description: 'Some error description',
+});
 ```
 
 Using the above, this is how the response would look:
@@ -150,7 +153,7 @@ Using the above, this is how the response would look:
 {
   "message": "Something bad happened",
   "error": "Some error description",
-  "statusCode": 400,
+  "statusCode": 400
 }
 ```
 
@@ -278,7 +281,7 @@ To create a global-scoped filter, you would do the following:
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
   app.useGlobalFilters(new HttpExceptionFilter());
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 ```
@@ -394,7 +397,7 @@ async function bootstrap() {
   const { httpAdapter } = app.get(HttpAdapterHost);
   app.useGlobalFilters(new AllExceptionsFilter(httpAdapter));
 
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 ```

content/faq/keep-alive-connections.md

@@ -18,7 +18,7 @@ async function bootstrap() {
   const app = await NestFactory.create(AppModule, {
     forceCloseConnections: true,
   });
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 
 bootstrap();

content/faq/multiple-servers.md

@@ -10,7 +10,7 @@ const httpsOptions = {
 const app = await NestFactory.create(AppModule, {
   httpsOptions,
 });
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 If you use the `FastifyAdapter`, create the application as follows:
@@ -33,10 +33,7 @@ const httpsOptions = {
 };
 
 const server = express();
-const app = await NestFactory.create(
-  AppModule,
-  new ExpressAdapter(server),
-);
+const app = await NestFactory.create(AppModule, new ExpressAdapter(server));
 await app.init();
 
 const httpServer = http.createServer(server).listen(3000);
@@ -56,7 +53,8 @@ export class ShutdownObserver implements OnApplicationShutdown {
 
   public async onApplicationShutdown(): Promise<void> {
     await Promise.all(
-      this.httpServers.map((server) =>
+      this.httpServers.map(
+        (server) =>
           new Promise((resolve, reject) => {
             server.close((error) => {
               if (error) {
@@ -65,7 +63,7 @@ export class ShutdownObserver implements OnApplicationShutdown {
                 resolve(null);
               }
             });
-        })
+          }),
       ),
     );
   }

content/faq/raw-body.md

@@ -17,7 +17,7 @@ import { AppModule } from './app.module';
 const app = await NestFactory.create<NestExpressApplication>(AppModule, {
   rawBody: true,
 });
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 To access the raw request body in a controller, a convenience interface `RawBodyRequest` is provided to expose a `rawBody` field on the request: use the interface `RawBodyRequest` type:
@@ -77,7 +77,7 @@ const app = await NestFactory.create<NestFastifyApplication>(
     rawBody: true,
   },
 );
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 To access the raw request body in a controller, a convenience interface `RawBodyRequest` is provided to expose a `rawBody` field on the request: use the interface `RawBodyRequest` type:

content/faq/serverless.md

@@ -37,7 +37,7 @@ import { AppModule } from './app.module';
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule, { logger: ['error'] });
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 

content/first-steps.md

@@ -56,7 +56,7 @@ import { AppModule } from './app.module';
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 @@switch
@@ -65,7 +65,7 @@ import { AppModule } from './app.module';
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 ```

content/fundamentals/lifecycle-events.md

@@ -84,7 +84,7 @@ async function bootstrap() {
   // Starts listening for shutdown hooks
   app.enableShutdownHooks();
 
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 ```

content/middlewares.md

@@ -22,7 +22,6 @@ You implement custom Nest middleware in either a function, or in a class with an
 
 > warning **Warning** `Express` and `fastify` handle middleware differently and provide different method signatures, read more [here](/techniques/performance#middleware).
 
-
 ```typescript
 @@filename(logger.middleware)
 import { Injectable, NestMiddleware } from '@nestjs/common';
@@ -132,7 +131,10 @@ export class AppModule {
 Pattern based routes are supported as well. For instance, the asterisk is used as a **wildcard**, and will match any combination of characters:
 
 ```typescript
-forRoutes({ path: 'ab*cd', method: RequestMethod.ALL });
+forRoutes({
+  path: 'ab*cd',
+  method: RequestMethod.ALL,
+});
 ```
 
 The `'ab*cd'` route path will match `abcd`, `ab_cd`, `abecd`, and so on. The characters `?`, `+`, `*`, and `()` may be used in a route path, and are subsets of their regular expression counterparts. The hyphen ( `-`) and the dot (`.`) are interpreted literally by string-based paths.
@@ -245,7 +247,7 @@ If we want to bind middleware to every registered route at once, we can use the
 @@filename(main)
 const app = await NestFactory.create(AppModule);
 app.use(logger);
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 > info **Hint** Accessing the DI container in a global middleware is not possible. You can use a [functional middleware](middleware#functional-middleware) instead when using `app.use()`. Alternatively, you can use a class middleware and consume it with `.forRoutes('*')` within the `AppModule` (or any other module).

content/openapi/introduction.md

@@ -32,7 +32,7 @@ async function bootstrap() {
   const document = SwaggerModule.createDocument(app, config);
   SwaggerModule.setup('api', app, document);
 
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 ```
@@ -62,14 +62,15 @@ As you can see, the `SwaggerModule` automatically reflects all of your endpoints
 
 > info **Hint** To generate and download a Swagger JSON file, navigate to `http://localhost:3000/api-json` (assuming that your Swagger documentation is available under `http://localhost:3000/api`).
 > It is also possible to expose it on a route of your choice using only the setup method from `@nestjs/swagger`, like this:
+>
 > ```typescript
 > SwaggerModule.setup('swagger', app, document, {
 >   jsonDocumentUrl: 'swagger/json',
 > });
 > ```
+>
 > Which would expose it at `http://localhost:3000/swagger/json`
 
-
 > warning **Warning** When using `fastify` and `helmet`, there may be a problem with [CSP](https://developer.mozilla.org/en-US/docs/Web/HTTP/CSP), to solve this collision, configure the CSP as shown below:
 >
 > ```typescript

content/openapi/other-features.md

@@ -75,7 +75,7 @@ async function bootstrap() {
   });
   SwaggerModule.setup('api/dogs', app, dogDocument);
 
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 ```

content/pipes.md

@@ -430,7 +430,7 @@ Since the `ValidationPipe` was created to be as generic as possible, we can real
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
   app.useGlobalPipes(new ValidationPipe());
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 ```

content/recipes/hot-reload.md

@@ -60,7 +60,7 @@ declare const module: any;
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 
   if (module.hot) {
     module.hot.accept();
@@ -127,10 +127,7 @@ module.exports = {
   resolve: {
     extensions: ['.tsx', '.ts', '.js'],
   },
-  plugins: [
-    new webpack.HotModuleReplacementPlugin(),
-    new RunScriptWebpackPlugin({ name: 'server.js', autoRestart: false }),
-  ],
+  plugins: [new webpack.HotModuleReplacementPlugin(), new RunScriptWebpackPlugin({ name: 'server.js', autoRestart: false })],
   output: {
     path: path.join(__dirname, 'dist'),
     filename: 'server.js',
@@ -151,7 +148,7 @@ declare const module: any;
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 
   if (module.hot) {
     module.hot.accept();

content/security/cors.md

@@ -9,7 +9,7 @@ To enable CORS, call the `enableCors()` method on the Nest application object.
 ```typescript
 const app = await NestFactory.create(AppModule);
 app.enableCors();
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 The `enableCors()` method takes an optional configuration object argument. The available properties of this object are described in the official [CORS](https://github.com/expressjs/cors#configuration-options) documentation. Another way is to pass a [callback function](https://github.com/expressjs/cors#configuring-cors-asynchronously) that lets you define the configuration object asynchronously based on the request (on the fly).
@@ -19,5 +19,5 @@ Or, pass a [CORS configuration object](https://github.com/expressjs/cors#configu
 
 ```typescript
 const app = await NestFactory.create(AppModule, { cors: true });
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```

content/techniques/logger.md

@@ -21,7 +21,7 @@ To disable logging, set the `logger` property to `false` in the (optional) Nest
 const app = await NestFactory.create(AppModule, {
   logger: false,
 });
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 To enable specific logging levels, set the `logger` property to an array of strings specifying the log levels to display, as follows:
@@ -30,7 +30,7 @@ To enable specific logging levels, set the `logger` property to an array of stri
 const app = await NestFactory.create(AppModule, {
   logger: ['error', 'warn'],
 });
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 Values in the array can be any combination of `'log'`, `'fatal'`, `'error'`, `'warn'`, `'debug'`, and `'verbose'`.
@@ -45,7 +45,7 @@ You can provide a custom logger implementation to be used by Nest for system log
 const app = await NestFactory.create(AppModule, {
   logger: console,
 });
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 Implementing your own custom logger is straightforward. Simply implement each of the methods of the `LoggerService` interface as shown below.
@@ -93,7 +93,7 @@ You can then supply an instance of `MyLogger` via the `logger` property of the N
 const app = await NestFactory.create(AppModule, {
   logger: new MyLogger(),
 });
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 This technique, while simple, doesn't utilize dependency injection for the `MyLogger` class. This can pose some challenges, particularly for testing, and limit the reusability of `MyLogger`. For a better solution, see the <a href="techniques/logger#dependency-injection">Dependency Injection</a> section below.
@@ -148,7 +148,7 @@ const app = await NestFactory.create(AppModule, {
   bufferLogs: true,
 });
 app.useLogger(app.get(MyLogger));
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 > info **Note** In the example above, we set the `bufferLogs` to `true` to make sure all logs will be buffered until a custom logger is attached (`MyLogger` in this case) and the application initialisation process either completes or fails. If the initialisation process fails, Nest will fallback to the original `ConsoleLogger` to print out any reported error messages. Also, you can set the `autoFlushLogs` to `false` (default `true`) to manually flush logs (using the `Logger#flush()` method).
@@ -249,7 +249,7 @@ const app = await NestFactory.create(AppModule, {
   bufferLogs: true,
 });
 app.useLogger(new MyLogger());
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 > info **Hint** Alternatively, instead of setting `bufferLogs` to `true`, you could temporarily disable the logger with `logger: false` instruction. Be mindful that if you supply `logger: false` to `NestFactory.create`, nothing will be logged until you call `useLogger`, so you may miss some important initialization errors. If you don't mind that some of your initial messages will be logged with the default logger, you can just omit the `logger: false` option.

content/techniques/mvc.md

@@ -33,7 +33,7 @@ async function bootstrap() {
   app.setBaseViewsDir(join(__dirname, '..', 'views'));
   app.setViewEngine('hbs');
 
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 @@switch
@@ -50,7 +50,7 @@ async function bootstrap() {
   app.setBaseViewsDir(join(__dirname, '..', 'views'));
   app.setViewEngine('hbs');
 
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 ```
@@ -156,7 +156,7 @@ async function bootstrap() {
     },
     templates: join(__dirname, '..', 'views'),
   });
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 @@switch
@@ -177,7 +177,7 @@ async function bootstrap() {
     },
     templates: join(__dirname, '..', 'views'),
   });
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 ```

content/techniques/performance.md

@@ -34,7 +34,7 @@ async function bootstrap() {
     AppModule,
     new FastifyAdapter()
   );
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 ```
@@ -74,7 +74,6 @@ You can pass options into the Fastify constructor through the `FastifyAdapter` c
 new FastifyAdapter({ logger: true });
 ```
 
-
 #### Middleware
 
 Middleware functions retrieve the raw `req` and `res` objects instead of Fastify's wrappers. This is how the `middie` package works (that's used under the hood) and `fastify` - check out this [page](https://www.fastify.io/docs/latest/Reference/Middleware/) for more information,
@@ -128,7 +127,6 @@ newFeature() {
 
 > info **Hint** `@RouteConfig()` and `@RouteConstraints` are imported from `@nestjs/platform-fastify`.
 
-
 #### Example
 
 A working example is available [here](https://github.com/nestjs/nest/tree/master/sample/10-fastify).

content/techniques/validation.md

@@ -141,7 +141,7 @@ We'll start by binding `ValidationPipe` at the application level, thus ensuring
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
   app.useGlobalPipes(new ValidationPipe());
-  await app.listen(3000);
+  await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
 ```

content/techniques/versioning.md

@@ -40,7 +40,7 @@ const app = await NestFactory.create(AppModule);
 app.enableVersioning({
   type: VersioningType.URI,
 });
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 > warning **Notice** The version in the URI will be automatically prefixed with `v` by default, however the prefix value can be configured by setting the `prefix` key to your desired prefix or `false` if you wish to disable it.
@@ -62,7 +62,7 @@ app.enableVersioning({
   type: VersioningType.HEADER,
   header: 'Custom-Header',
 });
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 The `header` property should be the name of the header that will contain the version of the request.
@@ -84,7 +84,7 @@ app.enableVersioning({
   type: VersioningType.MEDIA_TYPE,
   key: 'v=',
 });
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 The `key` property should be the key and separator of the key-value pair that contains the version. For the example `Accept: application/json;v=2`, the `key` property would be set to `v=`.
@@ -130,7 +130,7 @@ app.enableVersioning({
   type: VersioningType.CUSTOM,
   extractor,
 });
-await app.listen(3000);
+await app.listen(process.env.PORT ?? 3000);
 ```
 
 #### Usage