@contractspec/lib.logger

Website: https://contractspec.io/

High-performance logging library optimized for Bun, with native ElysiaJS integration.

Purpose

To provide structured, performant logging with support for request tracing, timing, and varied output formats (JSON/Pretty). It includes a plugin for ElysiaJS to automatically log HTTP requests.

Installation

npm install @contractspec/lib.logger
# or
bun add @contractspec/lib.logger

Key Concepts

• Structured Logging: Logs are JSON objects by default for easy parsing.
• Context Awareness: Supports AsyncLocalStorage for request-scoped context (Trace IDs).
• Elysia Plugin: Drop-in middleware for Elysia apps.

Exports

• logger: The main logger instance.
• elysiaPlugin: Middleware for Elysia.
• timer: Utilities for measuring execution time.
• tracer: Request tracing utilities.

Usage

Basic Logging

import { logger } from '@contractspec/lib.logger';

logger.info('Server started', { port: 3000 });
logger.error('Database connection failed', { error: err });

With Elysia

import { Elysia } from 'elysia';
import { elysiaLogger } from '@contractspec/lib.logger/elysia-plugin';

new Elysia()
  .use(elysiaLogger())
  .get('/', () => 'Hello World')
  .listen(3000);