node/test/parallel/test-event-emitter-add-listeners.js
Ruben Bridgewater c6b6c92185
lib: always show ERR_INVALID_ARG_TYPE received part
This makes a effort to make sure all of these errors will actually
also show the received input.
On top of that it refactors a few tests for better maintainability.
It will also change the returned type to always be a simple typeof
instead of special handling null.

PR-URL: https://github.com/nodejs/node/pull/19445
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
2018-03-25 01:45:37 +01:00

98 lines
3.1 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,
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// 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]);
}
// Verify that the listener must be a function
common.expectsError(() => {
const ee = new EventEmitter();
ee.on('foo', null);
}, {
code: 'ERR_INVALID_ARG_TYPE',
type: TypeError,
message: 'The "listener" argument must be of type Function. ' +
'Received type object'
});