@jterrazz/logger

Structured, type-safe logging for Node.js with pluggable adapters.

Installation

npm install @jterrazz/logger

Usage

import { PinoLoggerAdapter } from '@jterrazz/logger';

const logger = new PinoLoggerAdapter({
    level: 'debug',
    prettyPrint: true,
});

logger.info('Server started', { port: 3000 });
logger.error('Request failed', { error: new Error('Connection timeout') });

Child Loggers

Create scoped loggers with persistent context:

const requestLogger = logger.child({ requestId: 'abc-123' });
requestLogger.info('Processing request'); // Includes requestId in every log

Adapters

PinoLoggerAdapter

Production-ready logging powered by Pino.

import { PinoLoggerAdapter } from '@jterrazz/logger';

const logger = new PinoLoggerAdapter({
    level: 'info', // 'debug' | 'info' | 'warn' | 'error' | 'silent'
    prettyPrint: true, // Human-readable output for development
    destination: stream, // Optional custom destination stream
});

NoopLoggerAdapter

Zero-overhead adapter for environments where logging should be disabled.

import { NoopLoggerAdapter } from '@jterrazz/logger';

const logger = new NoopLoggerAdapter();

Metadata Behavior

The optional meta object provides contextual information:

Mode	Output
prettyPrint: true	Keys spread at root level for readability
prettyPrint: false	Nested under meta key for structured ingestion

logger.info('User login', { userId: 42 });

// prettyPrint: true  → { level: 'info', msg: 'User login', userId: 42 }
// prettyPrint: false → { level: 'info', msg: 'User login', meta: { userId: 42 } }

Errors in meta.error are automatically serialized with message and stack properties.

Port Interface

Use LoggerPort for dependency injection:

import type { LoggerPort } from '@jterrazz/logger';

class UserService {
    constructor(private readonly logger: LoggerPort) {}

    createUser(name: string) {
        this.logger.info('Creating user', { name });
    }
}

License

MIT