nodejs/test/parallel/test-event-emitter-once.js

71 lines
2.1 KiB
JavaScript

// 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.
'use strict';
const common = require('../common');
const assert = require('assert');
const EventEmitter = require('events');
const e = new EventEmitter();
e.once('hello', common.mustCall());
e.emit('hello', 'a', 'b');
e.emit('hello', 'a', 'b');
e.emit('hello', 'a', 'b');
e.emit('hello', 'a', 'b');
function remove() {
assert.fail('once->foo should not be emitted');
}
e.once('foo', remove);
e.removeListener('foo', remove);
e.emit('foo');
e.once('e', common.mustCall(function() {
e.emit('e');
}));
e.once('e', common.mustCall());
e.emit('e');
{
// once() has different code paths based on the number of arguments being
// emitted. Verify that all of the cases are covered.
const maxArgs = 4;
for (let i = 0; i <= maxArgs; ++i) {
const ee = new EventEmitter();
const args = ['foo'];
for (let j = 0; j < i; ++j)
args.push(j);
ee.once('foo', common.mustCall((...params) => {
assert.deepStrictEqual(params, args.slice(1));
}));
EventEmitter.prototype.emit.apply(ee, args);
}
}