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import chai from 'chai';

import chaiAsPromised from 'chai-as-promised';

import { assert as assertInc } from '../counter.js';

import eventEmitter from '../../src/utils/eventEmitter.js';

chai.use(chaiAsPromised);

const expect = chai.expect;

describe('EventEmitter', () => {

let emitter = eventEmitter();

afterEach('Reset state', () => {

// TODO: Better way to clear events

emitter = eventEmitter();

});

afterEach(() => {

// Assert each function has asserted properly

assertInc(0, 'Failed to assert before finishing');

});

describe('the instance', () => {

it('is an object', () => {

expect(emitter).to.be.an.instanceOf(Object);

});

it('is immutable', () => {

expect(emitter).to.be.frozen;

});

it('has all properties', () => {

const properties = {

on: 'function',

once: 'function',

one: 'function',

until: 'function',

emit: 'function',

cancelable: 'this',

canceled: 'this',

singleton: 'this',

async: 'this',

};

Object.keys(properties).forEach((key) => {

expect(emitter).to.have.property(key);

const type = properties[key];

switch (type) {

case '': return;

case 'this':

expect(emitter[key]).to.equal(emitter);

break;

default:

expect(emitter[key]).to.be.a(type);

}

});

});

it('should be extendable', () => {

const emitter2 = {

...emitter,

};

['on', 'once', 'one', 'until'].forEach((key) => {

expect(emitter2[key]()).to.equal(emitter2);

});

});

});

describe('events', () => {

describe('on', () => {

it('should register');

it('should register different events');

it('should register multiple events');

it('should be chainable');

});

describe('emit', () => {

it('runs', () => {

emitter.on('test', () => {

expect().inc();

});

const res = emitter.emit('test');

expect(res.ran).to.be.true;

assertInc(1);

});

it('does not run', () => {

const { ran } = emitter.emit('test');

expect(ran).to.be.false;

});

it('runs multiple times', () => {

emitter.on('test', () => {

expect().inc();

});

// Not called yet

assertInc(0);

// Call twice

const { ran: emit1 } = emitter.emit('test');

const { ran: emit2 } = emitter.emit('test');

expect(emit1).to.be.true;

expect(emit2).to.be.true;

// Should now be 2

assertInc(2);

});

it('passes arguments', () => {

const args = [1, 2, 3];

emitter.on('test', (...rest) => {

expect(rest).to.deep.equal(args).and.inc();

});

emitter.emit('test', ...args);

assertInc(1);

});

it('passes an array', () => {

const args = [1, 2, 3];

emitter.on('test', (arg) => {

expect(arg).to.equal(args).and.inc();

});

emitter.emit('test', args);

assertInc(1);

});

});

describe('cancelable', () => {

it('should be canceled', () => {

emitter.on('test', function cancel() {

this.canceled = true;

expect(this.cancelable).to.be.true.and.inc();

});

const { canceled } = emitter.cancelable.emit('test');

expect(canceled).to.be.true;

assertInc(1);

});

it('should not be canceled', () => {

emitter.on('test', () => {});

const { canceled } = emitter.cancelable.emit('test');

expect(canceled).to.be.false;

});

it('should not be canceled if not cancelable', () => {

emitter.on('test', function cancel() {

expect(this.cancelable).to.be.false.and.inc();

this.canceled = true;

});

const { canceled } = emitter.emit('test');

expect(canceled).to.be.false;

assertInc(1);

});

});

describe('canceled', () => {

function test() {

expect(this.cancelable).to.be.true.and.inc();

expect(this.canceled).to.be.true.and.inc();

}

it('is canceled from the start', () => {

emitter.on('test', test);

const { canceled } = emitter.canceled.emit('test');

expect(canceled).to.be.true;

assertInc(2);

});

it('should no longer be canceled', () => {

emitter.on('test', function cancel() {

test.call(this);

this.canceled = false;

});

const { canceled } = emitter.canceled.emit('test');

expect(canceled).to.be.false;

assertInc(2);

});

it('is canceled even if not ran', () => {

const { canceled } = emitter.canceled.emit('test');

expect(canceled).to.be.true;

});

});

describe('async', () => {

it('should return a promise');

it('should run');

it('should be cancelable');

it('should be canceled');

it('should not be canceled');

it('should be delayed');

it('should retain the awaited value');

});

describe('singleton', () => {

it('should emit once', () => {

emitter.on('test', () => {

expect().inc();

});

emitter.singleton.emit('test'); // Initial call

emitter.singleton.emit('test'); // Try to call again

emitter.emit('test'); // Try to call without singleton

assertInc(1);

});

it('should emit on delay', (done) => {

emitter.singleton.emit('test');

emitter.on('test', () => {

expect().inc();

});

setTimeout(() => {

assertInc(1);

done();

}, 1);

});

it.skip('should call again if reset');

});

describe('once', () => {

it('should be called once', () => {

emitter.once('test', () => {

expect().inc();

});

emitter.emit('test');

emitter.emit('test');

assertInc(1);

});

});

describe('one', () => {

it('should be called once', () => {

emitter.one('test', () => {

expect().inc();

});

emitter.emit('test');

emitter.emit('test');

assertInc(1);

});

});

describe('until', () => {

it('should be called thrice', () => {

emitter.until('test', (count) => {

expect().inc();

return count === 3;

});

for (let i = 0; i < 5; i++) {

emitter.emit('test', i + 1);

}

// Event is called 5 times, callback is only 3

assertInc(3);

});

it('should be called thrice (async)');

});

describe('off', () => {

it('should be called until turned off', () => {

function callback() {

expect().inc();

}

emitter.on('test', callback);

emitter.emit('test');

assertInc(1);

emitter.off('test', callback);

emitter.emit('test');

assertInc(0);

});

});

});

describe('Extend', () => {

it('should override on');

it('should still process parent emit');

});

});