Browse files

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.
  • Loading branch information...
1 parent c4fa77a commit 025f53c306d91968b292051404aebb8bf2adb458 @TooTallNate TooTallNate committed Aug 24, 2012
Showing with 128 additions and 17 deletions.
  1. +48 −17 lib/console.js
  2. +80 −0 test/simple/test-console-instance.js
View
65 lib/console.js
@@ -21,57 +21,88 @@
var util = require('util');
-exports.log = function() {
- process.stdout.write(util.format.apply(this, arguments) + '\n');
+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');
};
-exports.info = exports.log;
+Console.prototype.info = Console.prototype.log;
-exports.warn = function() {
- process.stderr.write(util.format.apply(this, arguments) + '\n');
+Console.prototype.warn = function() {
+ this._stderr.write(util.format.apply(this, arguments) + '\n');
};
-exports.error = exports.warn;
+Console.prototype.error = Console.prototype.warn;
-exports.dir = function(object) {
- process.stdout.write(util.inspect(object) + '\n');
+Console.prototype.dir = function(object) {
+ this._stdout.write(util.inspect(object) + '\n');
};
-var times = {};
-exports.time = function(label) {
- times[label] = Date.now();
+Console.prototype.time = function(label) {
+ this._times[label] = Date.now();
};
-exports.timeEnd = function(label) {
- var time = times[label];
+Console.prototype.timeEnd = function(label) {
+ var time = this._times[label];
if (!time) {
throw new Error('No such label: ' + label);
}
var duration = Date.now() - time;
- exports.log('%s: %dms', label, duration);
+ this.log('%s: %dms', label, duration);
};
-exports.trace = function(label) {
+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);
- console.error(err.stack);
+ this.error(err.stack);
};
-exports.assert = function(expression) {
+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;
View
80 test/simple/test-console-instance.js
@@ -0,0 +1,80 @@
+// 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 common = require('../common');
+var assert = require('assert');
+var Stream = require('stream');
+var Console = require('console').Console;
+var called = false;
+
+// ensure the Console instance doesn't write to the
+// process' "stdout" or "stderr" streams
+process.stdout.write = process.stderr.write = function() {
+ throw new Error('write() should not be called!');
+};
+
+// make sure that the "Console" function exists
+assert.equal('function', typeof Console);
+
+// make sure that the Console constructor throws
+// when not given a writable stream instance
+assert.throws(function () {
+ new Console();
+}, /Console expects a writable stream/);
+
+var out = new Stream();
+var err = new Stream();
+out.writable = err.writable = true;
+out.write = err.write = function(d) {};
+
+var c = new Console(out, err);
+
+out.write = err.write = function(d) {
+ assert.equal(d, 'test\n');
+ called = true;
+};
+
+assert(!called);
+c.log('test');
+assert(called);
+
+called = false;
+c.error('test');
+assert(called);
+
+out.write = function(d) {
+ assert.equal('{ foo: 1 }\n', d);
+ called = true;
+};
+
+called = false;
+c.dir({ foo: 1 });
+assert(called);
+
+// ensure that the console functions are bound to the console instance
+called = 0;
+out.write = function(d) {
+ called++;
+ assert.equal(d, called + ' ' + (called - 1) + ' [ 1, 2, 3 ]\n');
+};
+[1, 2, 3].forEach(c.log);
+assert.equal(3, called);

0 comments on commit 025f53c

Please sign in to comment.