node/test/parallel/test-event-emitter-add-listeners.js
Adrian Estrada cea853cb02
test: refactor events tests for invalid listeners
PR-URL: https://github.com/nodejs/node/pull/32769
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
2020-04-24 16:26:42 +02:00

87 lines
2.8 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 ee = new EventEmitter();
const events_new_listener_emitted = [];
const listeners_new_listener_emitted = [];
// Sanity check
assert.strictEqual(ee.addListener, ee.on);
ee.on('newListener', function(event, listener) {
// Don't track newListener listeners.
if (event === 'newListener')
return;
events_new_listener_emitted.push(event);
listeners_new_listener_emitted.push(listener);
});
const hello = common.mustCall(function(a, b) {
assert.strictEqual(a, 'a');
assert.strictEqual(b, 'b');
});
ee.once('newListener', function(name, listener) {
assert.strictEqual(name, 'hello');
assert.strictEqual(listener, hello);
assert.deepStrictEqual(this.listeners('hello'), []);
});
ee.on('hello', hello);
ee.once('foo', assert.fail);
assert.deepStrictEqual(['hello', 'foo'], events_new_listener_emitted);
assert.deepStrictEqual([hello, assert.fail], listeners_new_listener_emitted);
ee.emit('hello', 'a', 'b');
}
// Just make sure that this doesn't throw:
{
const f = new EventEmitter();
f.setMaxListeners(0);
}
{
const listen1 = () => {};
const listen2 = () => {};
const ee = new EventEmitter();
ee.once('newListener', function() {
assert.deepStrictEqual(ee.listeners('hello'), []);
ee.once('newListener', function() {
assert.deepStrictEqual(ee.listeners('hello'), []);
});
ee.on('hello', listen2);
});
ee.on('hello', listen1);
// The order of listeners on an event is not always the order in which the
// listeners were added.
assert.deepStrictEqual(ee.listeners('hello'), [listen2, listen1]);
}