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Nestjs error handling

Skill FilippoDeSilva/skills/skills/nestjs/nestjs-error-handling

Skills for my agentic development workflow.

Install
npx -y skills add FilippoDeSilva/skills --skill nestjs-error-handling

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What its author says it does

Copied from the file, not written here

Implement Global Exception Filters and standard error formats in NestJS. Use when implementing global exception filters or standardizing error responses in NestJS.

The file declares its own license as MIT. That is the author’s claim about this one file, and it is not the same thing as the license GitHub reports for the repository, which is listed with the other numbers below.

SKILL.md

2.4 KB, as published. Nobody here has run it

NestJS Error Handling Standards

Priority: P1 (OPERATIONAL)

  • Requirement: Centralize error formatting.
  • Platform Agnostic: not import Request/Response from Express/Fastify types directly.
  • Use: HttpAdapterHost to access underlying platform response methods.
  • const { httpAdapter } = this.httpAdapterHost;
  • Structure:
  • Implement strictly typed error responses.
  • Refer to API Standards for ApiErrorResponse.
 {
   "statusCode": 400,
   "message": "Validation failed",
   "error": "Bad Request",
   "timestamp": "ISO...",
   "path": "/users"
 }

Error Flow

  1. Service: Throws specific or generic errors (e.g., EntityNotFoundError).
  2. Interceptor: Maps low-level errors to HTTP Exceptions (e.g., catchError(err => throw new NotFoundException())).
  • Why: Keeps Exception Filters focused on formatting, not business logic interpretation.
  1. Global Filter: Formats final JSON response.

Built-in Exceptions

  • Use: Throw NotFoundException, ForbiddenException, BadRequestException.
  • Custom: Extend HttpException only for domain-specific failures that need specific status codes.

Logging

  • Context: Always pass MyClass.name to Logger constructor.
  • Levels:
  • error: 500s (Stack trace required).
  • warn: 400s (Client errors).

Security (Information Leakage)

  • Production: NEVER expose stack traces in HTTP responses (process.env.NODE_ENV === 'production').
  • Sanitization: Ensure ApiException payloads not leak internal file paths or raw variable dumps.

Anti-Patterns

  • No stack traces in production: Gate stack exposure behind NODE_ENV === 'production' check.
  • No Express types in filters: Use HttpAdapterHost for platform-agnostic error handling.
  • No HttpException in services: Throw domain errors in services; let Interceptors map to HTTP exceptions.

Keep looking

Skills are one crate of 328,083. Ordering is by how many stacks a row turns up in, so the top of any crate is what has actually been picked rather than what has the most stars.