events.js
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events.js
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	import { test, summary } from './helpers.js';
	import { EventEmitter } from 'ant:events';

	console.log('EventEmitter Tests\n');

	const ee = new EventEmitter();

	let received = null;
	ee.on('test', data => {
	received = data;
	});
	ee.emit('test', 'hello');
	test('on and emit', received, 'hello');

	let count = 0;
	ee.on('count', () => count++);
	ee.on('count', () => count++);
	ee.emit('count');
	test('multiple listeners', count, 2);

	let onceValue = 0;
	ee.once('once', val => {
	onceValue = val;
	});
	ee.emit('once', 42);
	ee.emit('once', 100);
	test('once only fires once', onceValue, 42);

	let removed = false;
	const handler = () => {
	removed = true;
	};
	ee.on('remove', handler);
	ee.off('remove', handler);
	ee.emit('remove');
	test('off removes listener', removed, false);

	let allRemoved = 0;
	ee.on('all', () => allRemoved++);
	ee.on('all', () => allRemoved++);
	ee.removeAllListeners('all');
	ee.emit('all');
	test('removeAllListeners', allRemoved, 0);

	test('listenerCount', ee.listenerCount('count'), 2);

	const names = ee.eventNames();
	test('eventNames includes count', names.includes('count'), true);

	const ee2 = new EventEmitter();
	let args = [];
	ee2.on('multi', (a, b, c) => {
	args = [a, b, c];
	});
	ee2.emit('multi', 1, 2, 3);
	test('multiple emit args', args.join(','), '1,2,3');

	const ee3 = new EventEmitter();
	test('emit returns false with no listeners', ee3.emit('none'), false);
	ee3.on('exists', () => {});
	test('emit returns true with listeners', ee3.emit('exists'), true);

	const ee4 = new EventEmitter();
	const chain = ee4
	.on('a', () => {})
	.once('b', () => {})
	.off('b', () => {});
	test('methods return this for chaining', chain, ee4);

	const ee5 = new EventEmitter();
	let aliasCount = 0;
	ee5.addListener('alias', () => aliasCount++);
	ee5.emit('alias');
	test('addListener alias works', aliasCount, 1);

	const ee6 = new EventEmitter();
	let removeAliasVal = 0;
	const removeAliasHandler = () => {
	removeAliasVal = 1;
	};
	ee6.on('rem', removeAliasHandler);
	ee6.removeListener('rem', removeAliasHandler);
	ee6.emit('rem');
	test('removeListener alias works', removeAliasVal, 0);

	const ee7 = new EventEmitter();
	let onceCount = 0;
	ee7.once('multi-once', () => onceCount++);
	ee7.once('multi-once', () => onceCount++);
	ee7.emit('multi-once');
	test('multiple once listeners fire', onceCount, 2);
	ee7.emit('multi-once');
	test('multiple once listeners only fire once', onceCount, 2);

	const ee8 = new EventEmitter();
	test('listenerCount for non-existent event', ee8.listenerCount('nope'), 0);

	const ee9 = new EventEmitter();
	const h = () => {};
	ee9.on('temp', h);
	ee9.off('temp', h);
	test('eventNames excludes removed events', ee9.eventNames().includes('temp'), false);

	const eeA = new EventEmitter();
	const eeB = new EventEmitter();
	let aVal = 0,
	bVal = 0;
	eeA.on('x', () => aVal++);
	eeB.on('x', () => bVal++);
	eeA.emit('x');
	test('separate instances are isolated (A)', aVal, 1);
	test('separate instances are isolated (B)', bVal, 0);

	console.log('\nEventTarget Tests\n');

	const et = new EventTarget();
	let etReceived = null;
	et.addEventListener('click', e => {
	etReceived = e.type;
	});
	et.dispatchEvent('click');
	test('EventTarget addEventListener and dispatchEvent', etReceived, 'click');

	let etEvent = null;
	const et2 = new EventTarget();
	et2.addEventListener('custom', e => {
	etEvent = e;
	});
	et2.dispatchEvent('custom', { foo: 'bar' });
	test('event.type', etEvent.type, 'custom');
	test('event.target is EventTarget', etEvent.target, et2);
	test('event.detail', etEvent.detail.foo, 'bar');

	const et3 = new EventTarget();
	let et3Val = 0;
	const et3Handler = () => {
	et3Val++;
	};
	et3.addEventListener('rem', et3Handler);
	et3.removeEventListener('rem', et3Handler);
	et3.dispatchEvent('rem');
	test('EventTarget removeEventListener', et3Val, 0);

	const et4 = new EventTarget();
	let et4Count = 0;
	et4.addEventListener('once', () => et4Count++, { once: true });
	et4.dispatchEvent('once');
	et4.dispatchEvent('once');
	test('EventTarget once option', et4Count, 1);

	console.log('\nGlobal Event Tests\n');

	let globalReceived = null;
	addEventListener('global-test', e => {
	globalReceived = e.type;
	});
	dispatchEvent('global-test');
	test('global addEventListener and dispatchEvent', globalReceived, 'global-test');

	let globalRemoved = 0;
	const globalHandler = () => {
	globalRemoved++;
	};
	addEventListener('global-rem', globalHandler);
	removeEventListener('global-rem', globalHandler);
	dispatchEvent('global-rem');
	test('global removeEventListener', globalRemoved, 0);

	summary();

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