yeti/lib/event-emitter.js

Yeti automates browser testing.

"use strict";

/**
 * @module events
 */

var util = require("util");
var EventEmitter2 = require("eventemitter2").EventEmitter2;

/**
 * An extension of EventEmitter2.
 *
 * Provided as `exports.EventEmitter2`.
 *
 * @class YetiEventEmitter2
 * @constructor
 * @inherits EventEmitter2
 * @param {Object} options Options for EventEmitter2
 */
function YetiEventEmitter2(options) {
    if (!options) {
        options = {};
    }

    options.wildcard = true;

    EventEmitter2.call(this, options);
}

util.inherits(YetiEventEmitter2, EventEmitter2);

/**
 * Emit a debug log event.
 *
 * @method debug
 * @protected
 */
YetiEventEmitter2.prototype.debug = function debug() {
    var args = Array.prototype.slice.apply(arguments);
    args.unshift(["log", "debug"]);
    this.emit.apply(this, args);
};

function getName(context) {
    var id,
        name = context.constructor.name;

    if (!name) {
        name = "Unknown Source";
    }

    if (context.id) {
        id = context.id;
    } else if (context.name) {
        id = context.name;
    }

    if (id) {
        name += "#" + id;
    }

    return "<" + name + ">";
}

/**
 * Re-emit log messages on the provided target.
 *
 * @method pipeLog
 * @param {EventEmitter2} target Re-emit log messages on this target.
 */
YetiEventEmitter2.prototype.pipeLog = function pipeLog(target) {
    this.on("log.**", function reflector() {
        var args = Array.prototype.slice.apply(arguments);
        args.unshift(getName(this) + " ->");
        args.unshift(this.event);
        target.emit.apply(target, args);
    });
};

/**
 * Setup listeners to log events that print
 * messages at the given loglevel to the console.
 *
 * @method printLogEventsForLevel
 * @param {String} name Name to prepend to these messages.
 * @param {String} loglevel The level, either debug, info, or silent.
 */
YetiEventEmitter2.prototype.printLogEventsForLevel = function (name, loglevel) {
    if (loglevel === "silent") {
        return;
    }

    function logListener() {
        /*jshint validthis: true */
        console.error.apply(this, [
            "[" + name + "]",
            "[" + this.event[1] + "]",
            "[" + (new Date()).toString() + "]",
        ].concat(Array.prototype.slice.call(arguments, 0)));
    }

    if (loglevel === "debug") {
        this.on("log.debug", logListener);
    }

    if (loglevel === "debug" || loglevel === "info") {
        this.on("log.info", logListener);
        this.on("log.warn", logListener);
    }
};

module.exports = YetiEventEmitter2;