Execution Order & Scopes

Preview — 3 of 10 questions

Place these in the correct order for a single successful request: Pipes, Guards, Interceptors (pre), Route Handler, Interceptors (post), Middleware.

javascript

// Single request happy path:
// Middleware -> Guards -> Interceptor(pre) -> Pipes -> Handler -> Interceptor(post)
//   (Exception Filters catch throws anywhere after middleware)

AMiddleware → Guards → Interceptors (pre) → Pipes → Handler → Interceptors (post)

BGuards → Middleware → Pipes → Interceptors (pre) → Handler → Interceptors (post)

CMiddleware → Pipes → Guards → Handler → Interceptors (pre) → Interceptors (post)

DInterceptors (pre) → Middleware → Guards → Pipes → Handler → Interceptors (post)

Guards are registered globally, on the controller, and on the method. In what order are they evaluated for a request?

javascript

// Evaluation order: APP_GUARD (global) -> @UseGuards on controller -> @UseGuards on method
// All must return true for the handler to run.

AMethod → Controller → Global

BGlobal → Controller → Method

CThey run in registration order regardless of scope

DOnly the most specific (method) guard runs

Two guards are listed in one @UseGuards(A, B). What logic combines them?

javascript

import { Controller, Get, UseGuards } from '@nestjs/common';
import { AuthGuard } from './auth.guard';
import { RolesGuard } from './roles.guard';

@Controller('admin')
@UseGuards(AuthGuard, RolesGuard) // AuthGuard AND RolesGuard must pass
export class AdminController {
  @Get() index() { return 'ok'; }
}

AOR — the request passes if either A or B returns true

BAND — both A and B must return true (and they short-circuit on the first false)

CXOR — exactly one must return true

DThey run independently and the last one wins

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