listeners-side-effects.js

// 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 EventEmitter = require('../').EventEmitter;

var e = new EventEmitter;
var fl;  // foo listeners

fl = e.listeners('foo');
assert(Array.isArray(fl));
assert(fl.length === 0);
assert.deepEqual(e._events, {});

e.on('foo', assert.fail);
fl = e.listeners('foo');
assert(e._events.foo === assert.fail);
assert(Array.isArray(fl));
assert(fl.length === 1);
assert(fl[0] === assert.fail);

e.listeners('bar');
assert(!e._events.hasOwnProperty('bar'));

e.on('foo', assert.ok);
fl = e.listeners('foo');

assert(Array.isArray(e._events.foo));
assert(e._events.foo.length === 2);
assert(e._events.foo[0] === assert.fail);
assert(e._events.foo[1] === assert.ok);

assert(Array.isArray(fl));
assert(fl.length === 2);
assert(fl[0] === assert.fail);
assert(fl[1] === assert.ok);