once.js 1.8 KB
// 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 assert = require('assert');
var events = require('../');

var e = new events.EventEmitter();
var times_hello_emited = 0;

e.once('hello', function(a, b) {
  times_hello_emited++;
});

e.emit('hello', 'a', 'b');
e.emit('hello', 'a', 'b');
e.emit('hello', 'a', 'b');
e.emit('hello', 'a', 'b');

var remove = function() {
  assert.fail(1, 0, 'once->foo should not be emitted', '!');
};

e.once('foo', remove);
e.removeListener('foo', remove);
e.emit('foo');

var times_recurse_emitted = 0;

e.once('e', function() {
	e.emit('e');
	times_recurse_emitted++;
});

e.once('e', function() {
	times_recurse_emitted++;
});

e.emit('e');

assert.equal(1, times_hello_emited);
assert.equal(2, times_recurse_emitted);