TestQA/node_modules/events/tests/once.js

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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);