Versioning & Streaming

Preview — 3 of 10 questions

You call app.enableVersioning({ type: VersioningType.URI }). What URL shape does a @Version('1') controller now serve?

javascript

import { VersioningType } from '@nestjs/common';
// main.ts
app.enableVersioning({ type: VersioningType.URI }); // default prefix 'v'

@Controller({ path: 'users', version: '1' })
export class UsersV1Controller {} // serves /v1/users

A/users with header X-Version: 1

B/users with media type application/vnd.api+json;v=1

C/users?version=1

D/v1/users

What does @Res({ passthrough: true }) allow that a plain @Res() does not?

javascript

import { Controller, Get, Res } from '@nestjs/common';
import { Response } from 'express';

@Controller('auth')
export class AuthController {
  @Get('me')
  me(@Res({ passthrough: true }) res: Response) {
    res.cookie('seen', '1'); // side effect on raw response
    return { user: 'alice' }; // still serialized by Nest
  }
}

AIt lets you read the request body twice

BIt lets you use the raw response (e.g. set a cookie) while still returning a value for Nest to serialize

CIt disables all interceptors for the handler

DIt automatically streams the response

When would you inject @Next() into a route handler?

javascript

import { Controller, Get, Next, Res } from '@nestjs/common';
import { NextFunction, Response } from 'express';

@Controller('legacy')
export class LegacyController {
  @Get()
  handle(@Res() res: Response, @Next() next: NextFunction): void {
    if (!res.locals.ready) return next(); // defer to next middleware
    res.send('done');
  }
}

ATo pass control to the next Express middleware/handler in the chain

BTo call the next route handler in NestJS's controller list

CTo advance an RxJS Observable

DTo trigger the next lifecycle hook

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