@listener-js/log

Listener logger

Install

npm install @listener-js/listener @listener-js/log

Enable logging

import { listener } from "@listener-js/listener"
import { log } from "@listener-js/log"

listener({ log })

Call logger directly

log.log([], "warn", "warning!")
// or
log.warn([], "warning!")

Log levels

There are six log levels: internal, trace, debug, info, warn, and error.

By default, the logger only logs messages at log level info or above. Change the log level through the LOG environment variable:

LOG=internal npm test

Or programmatically:

log.logLevel([], "internal")

Listener log level

You can also set log levels for specific listener functions:

log.logLevel([], "MyClass.myFn", "info")

Log strategies

There are three log strategies: args, argsJson, and ids (default).

Set the strategy via the LOG environment variable:

LOG=args npm test

To set the strategy and level, separate them with a colon (:):

LOG=trace:args npm test

Order does not matter when using the separator.

Log filtering

Pass a listener identifier to the LOG environment variable to filter:

LOG=MyClass.myFn npm test

Add a filter, strategy, and level all at once:

LOG=MyClass.myFn:args:internal npm test