How does exception filter resolution order work when multiple filters are registered at different levels in NestJS?

Q: How does exception filter resolution order work when multiple filters are registered at different levels in NestJS?

@UseFilters(HttpExceptionFilter) // controller — @Catch(HttpException) @Controller('users') export class UsersController { @UseFilters(NotFoundExceptionFilter) // method — @Catch(NotFoundException) @Get(':id') findOne() {} } // NotFoundException thrown on findOne(): // 1. NotFoundExceptionFilter (method) — @Catch(NotFoundException) matches -> handles it // UnauthorizedException thrown on findOne(): // 1. NotFoundExceptionFilter (method) — does NOT match // 2. HttpExceptionFilter (controller) — @Catch(HttpException) matches -> handles it // TypeError thrown on findOne(): // 1. NotFoundExceptionFilter (method) — does NOT match // 2. HttpExceptionFilter (controller) — does NOT match // 3. Global AllExceptionsFilter — @Catch() matches -> handles it Resolution order: method-level first, then controller-level, then global. This is the OPPOSITE of guards and interceptors which run global -> controller -> method. The first filter whose @Catch() type matches the thrown exception handles it exclusively. @Catch(NotFoundException) will NOT handle BadRequestException — types must match exactly. @Catch() with no argument at global level acts as the final catch-all safety net.

Difficulty: 6/10

exception filters, filter hierarchy, resolution order

Unlike guards and interceptors (global → controller → method), exception filters resolve in reverse: method → controller → global. The most specific, narrowest-scoped filter whose @Catch() type matches the thrown exception handles it. Wider-scoped filters only run as fallbacks when no narrower filter matches.

Filter resolution order example

Filter resolution rules:

1
Resolution order: method-level first, then controller-level, then global.
2
This is the OPPOSITE of guards and interceptors which run global -> controller -> method.

How does exception filter resolution order work when multiple filters are registered at different levels in NestJS?

Difficulty: 6/10

exception filters, filter hierarchy, resolution order

Unlike guards and interceptors (global → controller → method), exception filters resolve in reverse: method → controller → global. The most specific, narrowest-scoped filter whose @Catch() type matches the thrown exception handles it. Wider-scoped filters only run as fallbacks when no narrower filter matches.

Filter resolution order example

Filter resolution rules:

1
Resolution order: method-level first, then controller-level, then global.
2
This is the OPPOSITE of guards and interceptors which run global -> controller -> method.

How does exception filter resolution order work when multiple filters are registered at different levels in NestJS?

How does exception filter resolution order work when multiple filters are registered at different levels in NestJS?

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