Logger.js

/*
 MIT License http://www.opensource.org/licenses/mit-license.php
 Author Tobias Koppers @sokra
 */

"use strict";

/**
 * @enum {string}
 */
const LogType = Object.freeze({
	error: "error", // message, c style arguments
	warn: "warn", // message, c style arguments
	info: "info", // message, c style arguments
	log: "log", // message, c style arguments
	debug: "debug", // message, c style arguments

	trace: "trace", // no arguments

	group: "group", // [label]
	groupCollapsed: "groupCollapsed", // [label]
	groupEnd: "groupEnd", // [label]

	profile: "profile", // [profileName]
	profileEnd: "profileEnd", // [profileName]

	time: "time", // name, time as [seconds, nanoseconds]

	clear: "clear", // no arguments
	status: "status" // message, arguments
});

exports.LogType = LogType;

/** @typedef {LogType} LogTypeEnum */

const LOG_SYMBOL = Symbol("webpack logger raw log method");
const TIMERS_SYMBOL = Symbol("webpack logger times");

class WebpackLogger {
	/**
	 * @param {function(LogType, any[]=): void} log log function
	 */
	constructor(log) {
		this[LOG_SYMBOL] = log;
	}

	error(...args) {
		this[LOG_SYMBOL](LogType.error, args);
	}

	warn(...args) {
		this[LOG_SYMBOL](LogType.warn, args);
	}

	info(...args) {
		this[LOG_SYMBOL](LogType.info, args);
	}

	log(...args) {
		this[LOG_SYMBOL](LogType.log, args);
	}

	debug(...args) {
		this[LOG_SYMBOL](LogType.debug, args);
	}

	assert(assertion, ...args) {
		if (!assertion) {
			this[LOG_SYMBOL](LogType.error, args);
		}
	}

	trace() {
		this[LOG_SYMBOL](LogType.trace, ["Trace"]);
	}

	clear() {
		this[LOG_SYMBOL](LogType.clear);
	}

	status(...args) {
		this[LOG_SYMBOL](LogType.status, args);
	}

	group(...args) {
		this[LOG_SYMBOL](LogType.group, args);
	}

	groupCollapsed(...args) {
		this[LOG_SYMBOL](LogType.groupCollapsed, args);
	}

	groupEnd(...args) {
		this[LOG_SYMBOL](LogType.groupEnd, args);
	}

	profile(label) {
		this[LOG_SYMBOL](LogType.profile, [label]);
	}

	profileEnd(label) {
		this[LOG_SYMBOL](LogType.profileEnd, [label]);
	}

	time(label) {
		this[TIMERS_SYMBOL] = this[TIMERS_SYMBOL] || new Map();
		this[TIMERS_SYMBOL].set(label, process.hrtime());
	}

	timeLog(label) {
		const prev = this[TIMERS_SYMBOL] && this[TIMERS_SYMBOL].get(label);
		if (!prev) {
			throw new Error(`No such label '${label}' for WebpackLogger.timeLog()`);
		}
		const time = process.hrtime(prev);
		this[LOG_SYMBOL](LogType.time, [label, ...time]);
	}

	timeEnd(label) {
		const prev = this[TIMERS_SYMBOL] && this[TIMERS_SYMBOL].get(label);
		if (!prev) {
			throw new Error(`No such label '${label}' for WebpackLogger.timeEnd()`);
		}
		const time = process.hrtime(prev);
		this[TIMERS_SYMBOL].delete(label);
		this[LOG_SYMBOL](LogType.time, [label, ...time]);
	}
}

exports.Logger = WebpackLogger;