source: trip-planner-front/node_modules/events/tests/events-once.js@ fa375fe

Last change on this file since fa375fe was 6a3a178, checked in by Ema <ema_spirova@…>, 3 years ago

initial commit

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1'use strict';
2
3var common = require('./common');
4var EventEmitter = require('../').EventEmitter;
5var once = require('../').once;
6var has = require('has');
7var assert = require('assert');
8
9function Event(type) {
10 this.type = type;
11}
12
13function EventTargetMock() {
14 this.events = {};
15
16 this.addEventListener = common.mustCall(this.addEventListener);
17 this.removeEventListener = common.mustCall(this.removeEventListener);
18}
19
20EventTargetMock.prototype.addEventListener = function addEventListener(name, listener, options) {
21 if (!(name in this.events)) {
22 this.events[name] = { listeners: [], options: options || {} }
23 }
24 this.events[name].listeners.push(listener);
25};
26
27EventTargetMock.prototype.removeEventListener = function removeEventListener(name, callback) {
28 if (!(name in this.events)) {
29 return;
30 }
31 var event = this.events[name];
32 var stack = event.listeners;
33
34 for (var i = 0, l = stack.length; i < l; i++) {
35 if (stack[i] === callback) {
36 stack.splice(i, 1);
37 if (stack.length === 0) {
38 delete this.events[name];
39 }
40 return;
41 }
42 }
43};
44
45EventTargetMock.prototype.dispatchEvent = function dispatchEvent(arg) {
46 if (!(arg.type in this.events)) {
47 return true;
48 }
49
50 var event = this.events[arg.type];
51 var stack = event.listeners.slice();
52
53 for (var i = 0, l = stack.length; i < l; i++) {
54 stack[i].call(null, arg);
55 if (event.options.once) {
56 this.removeEventListener(arg.type, stack[i]);
57 }
58 }
59 return !arg.defaultPrevented;
60};
61
62function onceAnEvent() {
63 var ee = new EventEmitter();
64
65 process.nextTick(function () {
66 ee.emit('myevent', 42);
67 });
68
69 return once(ee, 'myevent').then(function (args) {
70 var value = args[0]
71 assert.strictEqual(value, 42);
72 assert.strictEqual(ee.listenerCount('error'), 0);
73 assert.strictEqual(ee.listenerCount('myevent'), 0);
74 });
75}
76
77function onceAnEventWithTwoArgs() {
78 var ee = new EventEmitter();
79
80 process.nextTick(function () {
81 ee.emit('myevent', 42, 24);
82 });
83
84 return once(ee, 'myevent').then(function (value) {
85 assert.strictEqual(value.length, 2);
86 assert.strictEqual(value[0], 42);
87 assert.strictEqual(value[1], 24);
88 });
89}
90
91function catchesErrors() {
92 var ee = new EventEmitter();
93
94 var expected = new Error('kaboom');
95 var err;
96 process.nextTick(function () {
97 ee.emit('error', expected);
98 });
99
100 return once(ee, 'myevent').then(function () {
101 throw new Error('should reject')
102 }, function (err) {
103 assert.strictEqual(err, expected);
104 assert.strictEqual(ee.listenerCount('error'), 0);
105 assert.strictEqual(ee.listenerCount('myevent'), 0);
106 });
107}
108
109function stopListeningAfterCatchingError() {
110 var ee = new EventEmitter();
111
112 var expected = new Error('kaboom');
113 var err;
114 process.nextTick(function () {
115 ee.emit('error', expected);
116 ee.emit('myevent', 42, 24);
117 });
118
119 // process.on('multipleResolves', common.mustNotCall());
120
121 return once(ee, 'myevent').then(common.mustNotCall, function (err) {
122 // process.removeAllListeners('multipleResolves');
123 assert.strictEqual(err, expected);
124 assert.strictEqual(ee.listenerCount('error'), 0);
125 assert.strictEqual(ee.listenerCount('myevent'), 0);
126 });
127}
128
129function onceError() {
130 var ee = new EventEmitter();
131
132 var expected = new Error('kaboom');
133 process.nextTick(function () {
134 ee.emit('error', expected);
135 });
136
137 var promise = once(ee, 'error');
138 assert.strictEqual(ee.listenerCount('error'), 1);
139 return promise.then(function (args) {
140 var err = args[0]
141 assert.strictEqual(err, expected);
142 assert.strictEqual(ee.listenerCount('error'), 0);
143 assert.strictEqual(ee.listenerCount('myevent'), 0);
144 });
145}
146
147function onceWithEventTarget() {
148 var et = new EventTargetMock();
149 var event = new Event('myevent');
150 process.nextTick(function () {
151 et.dispatchEvent(event);
152 });
153 return once(et, 'myevent').then(function (args) {
154 var value = args[0];
155 assert.strictEqual(value, event);
156 assert.strictEqual(has(et.events, 'myevent'), false);
157 });
158}
159
160function onceWithEventTargetError() {
161 var et = new EventTargetMock();
162 var error = new Event('error');
163 process.nextTick(function () {
164 et.dispatchEvent(error);
165 });
166 return once(et, 'error').then(function (args) {
167 var err = args[0];
168 assert.strictEqual(err, error);
169 assert.strictEqual(has(et.events, 'error'), false);
170 });
171}
172
173function prioritizesEventEmitter() {
174 var ee = new EventEmitter();
175 ee.addEventListener = assert.fail;
176 ee.removeAllListeners = assert.fail;
177 process.nextTick(function () {
178 ee.emit('foo');
179 });
180 return once(ee, 'foo');
181}
182
183var allTests = [
184 onceAnEvent(),
185 onceAnEventWithTwoArgs(),
186 catchesErrors(),
187 stopListeningAfterCatchingError(),
188 onceError(),
189 onceWithEventTarget(),
190 onceWithEventTargetError(),
191 prioritizesEventEmitter()
192];
193
194var hasBrowserEventTarget = false;
195try {
196 hasBrowserEventTarget = typeof (new window.EventTarget().addEventListener) === 'function' &&
197 new window.Event('xyz').type === 'xyz';
198} catch (err) {}
199
200if (hasBrowserEventTarget) {
201 var onceWithBrowserEventTarget = function onceWithBrowserEventTarget() {
202 var et = new window.EventTarget();
203 var event = new window.Event('myevent');
204 process.nextTick(function () {
205 et.dispatchEvent(event);
206 });
207 return once(et, 'myevent').then(function (args) {
208 var value = args[0];
209 assert.strictEqual(value, event);
210 assert.strictEqual(has(et.events, 'myevent'), false);
211 });
212 }
213
214 var onceWithBrowserEventTargetError = function onceWithBrowserEventTargetError() {
215 var et = new window.EventTarget();
216 var error = new window.Event('error');
217 process.nextTick(function () {
218 et.dispatchEvent(error);
219 });
220 return once(et, 'error').then(function (args) {
221 var err = args[0];
222 assert.strictEqual(err, error);
223 assert.strictEqual(has(et.events, 'error'), false);
224 });
225 }
226
227 common.test.comment('Testing with browser built-in EventTarget');
228 allTests.push([
229 onceWithBrowserEventTarget(),
230 onceWithBrowserEventTargetError()
231 ]);
232}
233
234module.exports = Promise.all(allTests);
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