@percy/logger

@percy/logger

Common logger used throughout the Percy CLI and SDKs.

• Usage
  • logger()
  • logger.loglevel()
  • logger.format()
  • logger.query()

Usage

import logger from '@percy/logger'

const log = logger('foobar')

log.info('info message')
log.error('error message')
log.warn('warning message')
log.debug('debug message')
log.deprecated('deprecation message')

logger([debug])

Creates a group of logging functions that will be associated with the provided debug label. When debug logging is enabled, this label is printed with the [percy:*] label and can be filtered via the PERCY_DEBUG environment variable.

PERCY_DEBUG="one:*,*:a,-*:b"

logger.loglevel('debug')

logger('one').debug('test')
logger('one:a').debug('test')
logger('one:b').debug('test')
logger('one:c').debug('test')
logger('two').debug('test')
logger('two:a').debug('test')

// only logs from the matching debug string are printed
//=> [percy:one] test
//=> [percy:one:a] test
//=> [percy:one:c] test
//=> [percy:two:a] test

logger.loglevel([level][, flags])

Sets or retrieves the log level of the shared logger. If the second argument is provided, level is treated as a fallback when all logging flags are false. When no arguments are provided, the method will return the current log level of the shared logger.

logger.loglevel('info', { verbose: true })
logger.loglevel() === 'debug'

logger.loglevel('info', { quiet: true })
logger.loglevel() === 'warn'

logger.loglevel('info', { silent: true })
logget.loglevel() === 'silent'

logger.loglevel('info')
logger.loglevel() === 'info'

logger.format(message, debug[, level])

Returns a formatted message depending on the provided level and logger's own log level. When debugging, the debug label is added to the prepended [percy:*] label.

logger.format('foobar', 'test')
//=> [percy] foobar

logger.loglevel('debug')
logger.format('foobar', 'test', warn')
//=> [percy:test] foobar (yellow for warnings)

logger.query(filter)

Returns an array of logs matching the provided filter function.

let logs = logger.query(log => {
  return log.level === 'debug' &&
    log.message.match(/foobar/)
})

Similar packages

Other packages similar to @percy/logger

winston

Winston is a versatile logging library for Node.js that supports multiple transports (e.g., console, file, HTTP) and log levels. It is highly configurable and can be used for both simple and complex logging needs. Compared to @percy/logger, Winston offers more advanced features and greater flexibility.

bunyan

Bunyan is a simple and fast JSON logging library for Node.js. It is designed to produce structured logs that are easy to parse and analyze. Bunyan provides features like log levels, serializers, and streams. Compared to @percy/logger, Bunyan focuses on structured logging and JSON output.

pino

Pino is a fast and low-overhead logging library for Node.js. It is designed for high-performance logging and provides features like log levels, serializers, and transports. Pino is known for its speed and efficiency, making it suitable for performance-critical applications. Compared to @percy/logger, Pino emphasizes performance and low overhead.