diff --git a/doc/api/events.markdown b/doc/api/events.markdown index b9be5dc5aad..692efa8155e 100644 --- a/doc/api/events.markdown +++ b/doc/api/events.markdown @@ -64,9 +64,6 @@ Remove a listener from the listener array for the specified event. Removes all listeners, or those of the specified event. -Note that this will **invalidate** any arrays that have previously been -returned by `emitter.listeners(event)`. - ### emitter.setMaxListeners(n) @@ -85,19 +82,6 @@ Returns an array of listeners for the specified event. }); console.log(util.inspect(server.listeners('connection'))); // [ [Function] ] -This array **may** be a mutable reference to the same underlying list of -listeners that is used by the event subsystem. However, certain -actions (specifically, removeAllListeners) will invalidate this -reference. - -If you would like to get a copy of the listeners at a specific point in -time that is guaranteed not to change, make a copy, for example by doing -`emitter.listeners(event).slice(0)`. - -In a future release of node, this behavior **may** change to always -return a copy, for consistency. In your programs, please do not rely on -being able to modify the EventEmitter listeners using array methods. -Always use the 'on' method to add new listeners. ### emitter.emit(event, [arg1], [arg2], [...]) diff --git a/lib/events.js b/lib/events.js index c2b604f8921..9778960f9da 100644 --- a/lib/events.js +++ b/lib/events.js @@ -242,5 +242,5 @@ EventEmitter.prototype.listeners = function(type) { if (!isArray(this._events[type])) { this._events[type] = [this._events[type]]; } - return this._events[type]; + return this._events[type].slice(0); }; diff --git a/test/simple/test-event-emitter-listeners.js b/test/simple/test-event-emitter-listeners.js new file mode 100644 index 00000000000..3e622835b85 --- /dev/null +++ b/test/simple/test-event-emitter-listeners.js @@ -0,0 +1,52 @@ + +// 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 events = require('events'); + +function listener() {} +function listener2() {} + +var e1 = new events.EventEmitter(); +e1.on('foo', listener); +var fooListeners = e1.listeners('foo'); +assert.deepEqual(e1.listeners('foo'), [listener]); +e1.removeAllListeners('foo'); +assert.deepEqual(e1.listeners('foo'), []); +assert.deepEqual(fooListeners, [listener]); + +var e2 = new events.EventEmitter(); +e2.on('foo', listener); +var e2ListenersCopy = e2.listeners('foo'); +assert.deepEqual(e2ListenersCopy, [listener]); +assert.deepEqual(e2.listeners('foo'), [listener]); +e2ListenersCopy.push(listener2); +assert.deepEqual(e2.listeners('foo'), [listener]); +assert.deepEqual(e2ListenersCopy, [listener, listener2]); + +var e3 = new events.EventEmitter(); +e3.on('foo', listener); +var e3ListenersCopy = e3.listeners('foo'); +e3.on('foo', listener2); +assert.deepEqual(e3.listeners('foo'), [listener, listener2]); +assert.deepEqual(e3ListenersCopy, [listener]);