log4js base

base.js

// base.js
 
function Base(options) {
	var category;
	// https://github.com/v8/v8/wiki/Stack-Trace-API
	try {
		category = ((new Error).stack.split('\n'))[2].match(/^\s+at\sBase\.(\w+)/)[1];
	}
	catch (e) {
		try {
			category = ((new Error).stack.split('\n'))[1].match(/^\s+at\s(\w+)\.Base/)[1];
		}
		catch (e) {
			throw new Error(
				'Could not set logging category from stack:\n' + (new Error).stack
			);
		}
	}

	/** @field {Logger} logger - An instance of {@link Logger}, with category set to reflect the invocant. */
	this.logger = require('./logger').getLogger(category);
}

logger.js

// logger.js

'use strict';

const log4js = require('log4js');

module.exports.configure = function (pathOrConfig) {
	if (process.env.LOG_EXC) {
		let exc = process.env.LOG_EXC.replace(/\s+/, '');
		if (exc.length > 0) {
			if (typeof pathOrConfig === 'string') {
				let configJson = require('fs').readFileSync(pathOrConfig);
				pathOrConfig = JSON.parse(configJson);
			}
			pathOrConfig.appenders.forEach((appender) => {
				if (appender.type === 'categoryFilter') {
					appender.exclude = appender.exclude || [];
					exc.split(/,/).forEach((i) => {
						appender.exclude.push(i);
					});
				}
			});
		}
	}

	log4js.configure(pathOrConfig);
	return module.exports.getLogger();
};

module.exports.getLogger = function () {
	logger = log4js.getLogger(_logger);

	if (typeof logger.setLevel === 'function') {
		let logLevel = process.env.LOG_LEVEL || 'TRACE';
		logger.setLevel(logLevel.toUpperCase());
	}

	return logger;
};