Slick NestJS Utils

Utility functions for NestJS applications, providing logging decorators and error handling helpers.

Installation

npm install @slickteam/nestjs-utils

API Reference

LoggerParams

Method decorator that automatically logs function parameters when called.

import { LoggerParams } from '@slickteam/nestjs-utils';

class UserService {
  @LoggerParams() // Default: 'verbose' level
  findUser(id: string, options: object) {
    // Logs: "findUser([0]=123,[1]={...})" at verbose level
  }

  @LoggerParams('debug')
  createUser(name: string) {
    // Logs: "createUser([0]="John")" at debug level
  }

  @LoggerParams({
    level: 'debug',
    paramNames: ['userId', 'userData'],
  })
  updateUser(id: string, data: object) {
    // Logs: "updateUser(userId="123", userData={...})" at debug level
  }
}

Parameters:

• level (optional): Log level - 'verbose' | 'debug' | 'log' | 'warn' | 'error'. Default: 'verbose'
• paramNames (optional): Array of parameter names to use instead of indices. If provided, must match the number of parameters.

Note: You can pass either a string for the log level, or an options object with level and paramNames properties.

throwErrorAndLog

Throws an HttpException and logs the error message.

import { HttpStatus, Logger } from '@nestjs/common';
import { throwErrorAndLog } from '@slickteam/nestjs-utils';

class UserService {
  private readonly logger = new Logger(UserService.name);

  findUser(id: string) {
    const user = this.repository.find(id);
    if (!user) {
      throwErrorAndLog('User not found', HttpStatus.NOT_FOUND, this.logger);
    }
    return user;
  }
}

Parameters:

• message: Error message to log and throw
• typeError (optional): HTTP status code. Default: HttpStatus.INTERNAL_SERVER_ERROR
• logger (optional): Logger instance. If not provided, uses the static Logger

throwErrorAndLogWithContext

Throws an HttpException and logs the error message with a context string.

import { HttpStatus } from '@nestjs/common';
import { throwErrorAndLogWithContext } from '@slickteam/nestjs-utils';

function validateInput(data: unknown) {
  if (!data) {
    throwErrorAndLogWithContext('Invalid input', HttpStatus.BAD_REQUEST, 'ValidationService');
  }
}

Parameters:

• message: Error message to log and throw
• typeError (optional): HTTP status code. Default: HttpStatus.INTERNAL_SERVER_ERROR
• context (optional): Context string for the logger

logLevel

Returns an array of log levels to enable, based on a minimum level (cascade).

import { logLevel } from '@slickteam/nestjs-utils';

// Returns ['debug', 'log', 'warn', 'error']
const levels = logLevel('debug');

// Usage with NestJS bootstrap
const app = await NestFactory.create(AppModule, {
  logger: logLevel('debug'),
});

Parameters:

• level: Minimum log level - 'verbose' | 'debug' | 'log' | 'warn' | 'error'

Returns: Array of LogLevel including the specified level and all levels above it.

Requirements

• Node.js >= 18
• NestJS >= 11

License

MIT