Node Logger

A compact NodeJS module to manage application logging. Designed to be easy to use with minimal (currently none) external dependencies.

Installation

To install using npm:

    npm i @thaerious/logger

Quick Start

The default behaviour provides a single channel called 'log' which outputs to the console. Inovking the channel as a function will process the passed in values.

    import Logger from "@thaerious/logger";
    const logger = new Logger();
    logger.log("hello world");

Adding Channels

Using a previously undefined channedl will create a new channel that outputs to the console.

    logger.verbose("ima debug statement!");

Disabling a Channel

Setting the enabled field on a channel to false will prevent all processing on that channel. To enable the channel set the enabled field to true.

    logger.log.enabled = false;
    logger.log.enabled = true;

Add Custom Handlers

When a channel receives input it is sent through a chain of handlers. The default is a single handler that outputs the input to the console verbatim.

A handler can either be a callback function or an object with a log function, such as console or another channel.

The callback function accepts 2 arguments: value, raw. The value argument is the value returned by the previous handler. The raw is the original object value into the channel. Note, the first handler receives the same value for both value and raw. The channel will return the result of the last handler.

Pass an array of handlers to handlers setter to set handlers, this will erase all previous handlers. Alternatively use #clearHandlers, prependHandler, or appendHandler.

logger.log.handlers = [
    (v) => `[log] ${v}`,
    someHandler,
    console
]

To prepend handlers, pass in the previous handlers.

logger.log.handlers = [
    (v) => `[log] ${v}`,
    someHandler,
    this.handlers
]