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nodejs/lib/console.js
Nathan Rajlich 025f53c306 console: refactor the console module to be reusable
So that multiple instances can be created pointing
to different writable streams.

This is needed for #3876.
2012-08-24 14:31:32 -07:00

109 lines
3.1 KiB
JavaScript

// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.
var util = require('util');
function Console(stdout, stderr) {
if (!(this instanceof Console)) {
return new Console(stdout, stderr);
}
if (!stdout || typeof stdout.write !== 'function') {
throw new TypeError('Console expects a writable stream instance');
}
if (!stderr) {
stderr = stdout;
}
var prop = {
writable: true,
enumerable: false,
configurable: true
};
prop.value = stdout;
Object.defineProperty(this, '_stdout', prop);
prop.value = stderr;
Object.defineProperty(this, '_stderr', prop);
prop.value = {};
Object.defineProperty(this, '_times', prop);
// bind the prototype functions to this Console instance
Object.keys(Console.prototype).forEach(function(k) {
this[k] = this[k].bind(this);
}, this);
}
Console.prototype.log = function() {
this._stdout.write(util.format.apply(this, arguments) + '\n');
};
Console.prototype.info = Console.prototype.log;
Console.prototype.warn = function() {
this._stderr.write(util.format.apply(this, arguments) + '\n');
};
Console.prototype.error = Console.prototype.warn;
Console.prototype.dir = function(object) {
this._stdout.write(util.inspect(object) + '\n');
};
Console.prototype.time = function(label) {
this._times[label] = Date.now();
};
Console.prototype.timeEnd = function(label) {
var time = this._times[label];
if (!time) {
throw new Error('No such label: ' + label);
}
var duration = Date.now() - time;
this.log('%s: %dms', label, duration);
};
Console.prototype.trace = function(label) {
// TODO probably can to do this better with V8's debug object once that is
// exposed.
var err = new Error;
err.name = 'Trace';
err.message = label || '';
Error.captureStackTrace(err, arguments.callee);
this.error(err.stack);
};
Console.prototype.assert = function(expression) {
if (!expression) {
var arr = Array.prototype.slice.call(arguments, 1);
require('assert').ok(false, util.format.apply(this, arr));
}
};
module.exports = new Console(process.stdout, process.stderr);
module.exports.Console = Console;