@torgeilo/logger

Tiny, customizable logger, designed for the browser.

Features

• Namespaces.
• Pluggable log handlers.
• Typed and customizable log levels (called tags internally).
• Basic minimal console log handler (default).
• Styled console log handler (separate bundle).
• No dependencies.

Getting started

Install:

npm install @torgeilo/logger

Use:

import{getLogger}from'@torgeilo/logger';constlogger=getLogger('my namespace');logger.log('Hello');logger.debug('world');

Default console output of the above, with log levels "log" and "debug":

my namespace: Hello
my namespace: world

Default log levels: debug, log, info, warn, error.

Customizing

Disable logging

Empty the logHandlers array however you prefer. A clear() method is added for convenience:

import{logHandlers}from'@torgeilo/logger';logHandlers.clear();

Styled console log handler

Import and add the styled console log handler to the logHandlers array.

import{logHandlers}from'@torgeilo/logger';import{StyledConsoleLogHandler}from'@torgeilo/logger/styled-console-log-handler.js';logHandlers.clear();// Remove the default log handler.logHandlers.push(newStyledConsoleLogHandler());

Custom log levels/tags

import{getLogger}from'@torgeilo/logger';constlogger=getLogger<'Finn'|'Jake'>('Together Again');logger.Finn('Oh, man, are they angry!');logger.Jake('Angry and fresh outta ice cream!');

Default console output (with level log):

TogetherAgain/Finn: Oh,man,aretheyangry!TogetherAgain/Jake: Angryandfreshouttaicecream!

Custom log handler

Implement the LogHandler interface and add your implementation to the logHandlers array. The interface:

exportinterfaceLogHandler{log(namespace: string,tag: string,message: unknown, ...messages: unknown[]): void;}

The tag is typically the log level, which can be checked using isLogLevel():

import{isLogLevel}from'@torgeilo/logger';consttag= ...;constmessage= ...;if(isLogLevel(tag)){console[tag](message);}else{console.log(`${tag}:`,message);}

Possibilities

You could:

• Make a log handler which only outputs errors or warnings.
• Make a log handler which shows the log in an HTML element on screen.
• Make a log handler which sends errors to a remote error tracker.
• Make a log handler which sends a custom tag to a remote tracker, like logger.metric(123);.
• Make a test reporter which logs the test run output, and a log handler which sends it somewhere useful, in addition to the console.

License

This software is licensed under the terms of the MIT license.

Contributing

Smaller bug reports are welcome.

I don't have capacity for much else. You're probably better off forking if you want to change things.