Parallel test

parallel-test.js

/*
 * You have to implement missing part of the application that making code below (which untouchble)
 * to be compiled and executed without exceptions and assertions.
 */
class Parallel {}

/************************************************
 * Please don`t change the code bellow this line *
 ************************************************/

const runner = new Parallel({
	parallelJobs: 2
});

let result = 'before/';

runner
	.job(step0)
	.job(step1)
	.job(step2)
	.job(step3)
	.job(step4)
	.done(onDone);


result += 'after/';

function step0(done) {
	console.log('step0');

	result += 'step0/';
	
	done('step0');
}

function step1(done) {
	console.log('step1');
	
	result += 'step1/';
	
	setTimeout(done, 3000, 'step1');
}

setTimeout(() => result += 'after0-1/', 2500);

function step2(done) {
	console.log('step2');

	result += 'step2/';

	setTimeout(done, 1500, 'step2');
}

function step3(done) {
	console.log('step3');

	result += 'step3/';

	setTimeout(done, 2000, 'step3');
}

setTimeout(() => result += 'after2-3/', 4500);

function step4(done) {
	console.log('step4');
	
	result += 'step4/';
	
	setTimeout(done, 500, 'step4');
}

setTimeout(() => result += 'after4/', 5500);

let isPassed = false;
function onDone(results) {
	console.log('onDone', results, result);

	console.assert(Array.isArray(results), 'expect result to be array');
	console.assert(results.length === 5, 'the results length must be 5');
	console.assert(results[0] === 'step0', 'Wrong answer 1');
	console.assert(results[1] === 'step1', 'Wrong answer 2');
	console.assert(results[2] === 'step2', 'Wrong answer 2');
	console.assert(results[3] === 'step3', 'Wrong answer 3');
	console.assert(results[4] === 'step4', 'Wrong answer 4');
	console.assert(result === 'before/after/step0/step1/after0-1/step2/step3/after2-3/step4/after4/', 'Wrong steps');
	console.log('Thanks, all works fine');
	
	isPassed = true;
}

setTimeout(() => {
	if(isPassed) return;

	console.error('Test is not done.');
}, 6000);