1// Copyright Joyent, Inc. and other Node contributors. 2// 3// Permission is hereby granted, free of charge, to any person obtaining a 4// copy of this software and associated documentation files (the 5// "Software"), to deal in the Software without restriction, including 6// without limitation the rights to use, copy, modify, merge, publish, 7// distribute, sublicense, and/or sell copies of the Software, and to permit 8// persons to whom the Software is furnished to do so, subject to the 9// following conditions: 10// 11// The above copyright notice and this permission notice shall be included 12// in all copies or substantial portions of the Software. 13// 14// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 15// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 16// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN 17// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 18// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 19// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 20// USE OR OTHER DEALINGS IN THE SOFTWARE. 21 22var common = require('./common'); 23var assert = require('assert'); 24var EventEmitter = require('../'); 25 26var e = new EventEmitter(); 27 28e.once('hello', common.mustCall()); 29 30e.emit('hello', 'a', 'b'); 31e.emit('hello', 'a', 'b'); 32e.emit('hello', 'a', 'b'); 33e.emit('hello', 'a', 'b'); 34 35function remove() { 36 assert.fail('once->foo should not be emitted'); 37} 38 39e.once('foo', remove); 40e.removeListener('foo', remove); 41e.emit('foo'); 42 43e.once('e', common.mustCall(function() { 44 e.emit('e'); 45})); 46 47e.once('e', common.mustCall()); 48 49e.emit('e'); 50 51// Verify that the listener must be a function 52assert.throws(function() { 53 var ee = new EventEmitter(); 54 55 ee.once('foo', null); 56}, /^TypeError: The "listener" argument must be of type Function. Received type object$/); 57 58{ 59 // once() has different code paths based on the number of arguments being 60 // emitted. Verify that all of the cases are covered. 61 var maxArgs = 4; 62 63 for (var i = 0; i <= maxArgs; ++i) { 64 var ee = new EventEmitter(); 65 var args = ['foo']; 66 67 for (var j = 0; j < i; ++j) 68 args.push(j); 69 70 ee.once('foo', common.mustCall(function() { 71 var params = Array.prototype.slice.call(arguments); 72 var restArgs = args.slice(1); 73 assert.ok(Array.isArray(params)); 74 assert.strictEqual(params.length, restArgs.length); 75 for (var index = 0; index < params.length; index++) { 76 var param = params[index]; 77 assert.strictEqual(param, restArgs[index]); 78 } 79 })); 80 81 EventEmitter.prototype.emit.apply(ee, args); 82 } 83} 84