@naturalcycles/logger-lib

PoC: Opinionated logger for Node.js and Browser

Features

• Opinionated api
• Pluggable Transports and Filters
• Flexible filtering by tags (debug-style) and log levels (DEBUG, INFO, WARN, ERROR)
• Built-in NoopTransport, NoopFilter, ConsoleTransport (prints everything via console.* methods)
• Built with TypeScript (types included)

Usage

// Minimal LoggerService
const logService = new LoggerService()

// Minimal Logger
let log = logService.getLogger()

// Filename as the only tag (node)
log = logService.getLogger(__filename)

// More tags that will be attached to every log message
log = logService.getLogger(__filename, 'tag1', 'tag2')

// Normal logging (will be used 80% of the time)
log('something')

// Supports multiple parameters, same as console.*
log('something', { a: 'b' }, { b: 'c' }, 'somethingElse')

// Specific level
log.debug('something')
log.info('something')
log.warn('something')
log.error('something')
log.log(LEVEL.INFO, 'something')

// Add tag to specific log message
log.tag('tag3').info('something')

// Add many tags to specific log message
log.tag('tag3', 'tag4').info('something')

// Custom level + tag
log.tag('tag1').warn('something')

// Meta (passed to Transports to deal with)
log.meta({ a: 'b' }).info('something')

Packaging

• engines.node >= 10.13: Latest Node.js LTS
• main: dist/index.js: commonjs, es2018
• types: dist/index.d.ts: typescript types
• /src folder with source *.ts files included