EventListener.test.ts

import { expect } from 'chai';
import 'mocha';
import { EventListener } from '../../src';

describe('EventListener', () => {
    let listenerResult;
    const callback = (data) => {
        listenerResult = data;
    };
    beforeEach(function () {
        listenerResult = null;
    });

    describe('#constructor()', function () {
        it('should create a new EventListener object', function () {
            expect(new EventListener('test', callback, null)).to.have.keys([
                'namespace',
                'callback',
                'once',
                'emitter'
            ]);
        });
    });

    describe('#execute()', function () {
        it('should execute the callback', function () {
            new EventListener('test', callback, null).execute(this, true);
            expect(listenerResult).to.equal(true);
        });
    });

    describe('#close()', function () {
        it('should remove itself from `emitter`', function () {
            const listener = new EventListener('test', callback, null);
            listener.open();
            expect(listener.emitter.listeners.length).to.equal(1);
            listener.close();
            expect(listener.emitter.listeners.length).to.equal(0);
        });
    });

    describe('#open()', function () {
        it('should add itself back to `emitter` (EventEmitter)', function () {
            const listener = new EventListener('test', callback);
            listener.open(true);
            expect(listener.emitter.listeners.length).to.equal(1);
        });
    });

    describe('#once', function () {
        it('should only execute the listener once and remove itself from `emitter`', function () {
            const listener = new EventListener('test', callback, null);
            listener.execute(this, true);
            expect(listener.emitter.listeners.length).to.equal(0);
        });
    });
});