@sylphx/cat-pretty

Pretty formatter for @sylphx/cat logger

0.81 KB • Beautiful colored output • Perfect for development

Installation

npm install @sylphx/cat @sylphx/cat-pretty

Description

A beautiful, human-readable formatter for @sylphx/cat logs. Adds colors, timestamps, and clean formatting to make logs easy to read during development. Optimized for terminal output with ANSI color support.

Usage Examples

Basic Pretty Logging

import { createLogger } from '@sylphx/cat'
import { prettyFormatter } from '@sylphx/cat-pretty'

const logger = createLogger({
  formatter: prettyFormatter()
})

logger.info('Server started', { port: 3000 })
// [2024-11-14T20:30:15.123Z] INF Server started {"port":3000}

logger.error('Connection failed', { host: 'db.example.com' })
// [2024-11-14T20:30:16.456Z] ERR Connection failed {"host":"db.example.com"}

Custom Timestamp Format

import { prettyFormatter } from '@sylphx/cat-pretty'

// ISO format (default)
const logger1 = createLogger({
  formatter: prettyFormatter({ timestampFormat: 'iso' })
})
logger1.info('Hello')
// [2024-11-14T20:30:15.123Z] INF Hello

// Unix timestamp
const logger2 = createLogger({
  formatter: prettyFormatter({ timestampFormat: 'unix' })
})
logger2.info('Hello')
// [1700000000000] INF Hello

// Relative time (ms since start)
const logger3 = createLogger({
  formatter: prettyFormatter({ timestampFormat: 'relative' })
})
logger3.info('Hello')
// [+1234ms] INF Hello

Disable Colors and Timestamps

import { prettyFormatter } from '@sylphx/cat-pretty'

const logger = createLogger({
  formatter: prettyFormatter({
    colors: false,
    timestamp: false
  })
})

logger.info('Hello world')
// INF Hello world

API Reference

prettyFormatter(options?: PrettyFormatterOptions): Formatter

Creates a pretty formatter instance.

Options:

• colors?: boolean - Enable ANSI colors (default: true)
• timestamp?: boolean - Show timestamps (default: true)
• timestampFormat?: 'iso' | 'unix' | 'relative' - Timestamp format (default: 'iso')

Color scheme:

• trace - Gray
• debug - Cyan
• info - Green
• warn - Yellow
• error - Red
• fatal - Magenta

Level labels:

• trace → TRC
• debug → DBG
• info → INF
• warn → WRN
• error → ERR
• fatal → FTL

Output Format

[timestamp] LEVEL message {data} [context]

Example:

[2024-11-14T20:30:15.123Z] INF User logged in {"userId":123} [service=auth requestId=abc-123]

Package Size

• Minified: ~2.5 KB
• Minified + Gzipped: 0.81 KB
• No additional dependencies

Links

• Main Documentation
• GitHub Repository
• npm Package

Related Packages

• @sylphx/cat - Core logger
• @sylphx/cat-file - File and stream transports
• @sylphx/cat-http - HTTP request/response serializers

License

MIT © Kyle Zhu