new Logger( context, level )

This micro-package provides a minimalist logging class for web browsers.

Overview

Bundled size is less than 2KB

Install

npm i @whi/weblogger

Usage

Browser

<script src="weblogger.bundled.js"></script>

<script type="text/javascript">
    const { Logger } = WebLogger;
    const log = new Logger( "main" );

    log.fatal("Testing");
    log.error("Testing");
    log.warn("Testing");
    log.normal("Testing"); // default level
    log.info("Testing");
    log.debug("Testing");
    log.trace("Testing");
</script>

Node

const { Logger } = require('@whi/weblogger');

const log = new Logger( "main", "debug" );

log.fatal("Testing");
log.error("Testing");
log.warn("Testing");
log.normal("Testing");
log.info("Testing");
log.debug("Testing");
log.trace("Testing"); // would not log

Set defaults using localStorage

window.localStorage.setItem("LOG_COLOR", "false"); // turn off coloring
window.localStorage.setItem("LOG_LEVEL", "debug"); // set default level to "debug"

Avoiding expensive arg computations

Short-circuit using logical operators

log.level.debug && log.debug("Expensive arg computation: %s", value.map(...).join(", ") );

Or, a callback function that only evaluates when a message will be logged.

log.debug("Expensive arg computation: %s", () => [ value.map(...).join(", ") ]);

API Reference

new Logger( context, level, colors )

Change this Logger's verbosity level.

• context - (required) an identifier used in the log format
• level - (optional) the starting log level
  • defaults to level 3 (normal)
• colors - (optional) a boolean for log coloring
  • defaults to true

<Logger>.setLevel( level )

Change this Logger's verbosity level.

• level - (required) the new log level

Returns the integer value of the new level.

Contributing

See CONTRIBUTING.md