4 Node.js bloatware testing frameworks: Ava, Jasmine, Jest, Mocha

Category: Dev Toolbox 2020-02-09 Łukasz Nojek

There are many frameworks for testing a Node.js project. Too many. And most of them require huge dependencies. Check the brief report below to find out.

Table of contents

Introduction
AVA
Jest
Jasmine
1. Jasmine + Karma
Mocha
1. Mocha + Chai
2. Mocha + Chai + Sinon
Titef
Summary

Introduction

I wrote a simple function that will be tested by the frameworks:

function divide(a, b) {
	return a / b;
}

module.exports = divide;

The source code is available in my GitHub repo.

AVA

Project: https://www.npmjs.com/package/ava

Version: 3.2.0

Dependencies: 52

Used in: 380 npm packages

Source code: 48k uses, 17k stars, 153 issues

Installation:

npm install -D ava

Size on disk: 8141 kB, 3002 files, 470 folders

Run tests:

ava

Sample test:

const test = require('ava');

const divide = require('../calculator');

test('should divide two numbers', t => {
	t.is(divide(10, 2), 5);
});

test('unexpected error', t => {
	t.is(divide(2, 0), 0);
});

Jest

Project: https://www.npmjs.com/package/jest

Version: 25.1.0

Dependencies: 3

Used in: 6557 npm packages

Source code: 1.6M uses, 30k stars, 811 issues

Installation:

npm install -D jest

Size on disk: 37,230 kB, 7211 files, 1174 folders

Run tests:

jest

Sample test:

const divide = require('../calculator');

test('should divide two numbers', () => {
	expect(divide(10, 2)).toBe(5);
});

test('unexpected error', () => {
	expect(divide(2, 0)).toBe(0);
});

Jasmine

Project: https://www.npmjs.com/package/jasmine

Version: 3.5.0

Dependencies: 2

Used in: 915 npm packages

Source code: 794k uses, 334 stars, 3 issues

Installation:

npm install -D jasmine
npx jasmine init

jasmine init creates sample configuration in spec/support/jasmine.json

Size on disk: 524 kB, 108 files, 38 folders

Run tests:

jasmine

Sample test:

const divide = require('../calculator');

test('should divide two numbers', () => {
	expect(divide(10, 2)).toBe(5);
});

test('unexpected error', () => {
	expect(divide(2, 0)).toBe(0);
});

Jasmine + Karma

Karma is a test runner that allows running tests in your browser. It’s useful when testing applications with user interface, like Angular. Karma is usually paired with Jasmine, though it works also with Mocha and other frameworks.

Project: https://www.npmjs.com/package/karma

Version: 4.4.1

Dependencies: 26

Used in: 1029 npm packages

Source code: 1.3M uses, 11k stars, 360 issues

Installation:

npm install -D jasmine-core karma karma-jasmine
karma init

jasmine-core is the subset of Jasmine
karma-jasmine is the Karma’s adapter for Jasmine
karma init creates configuration in karma.conf.js

Size on disk: 10,165 kB, 2494 files, 306 folders

Run tests:

karma start

Note: it took me a while to configure standalone Karma. Here are the relevant steps:

The test will be executed in a browser that does not understand importing files (the test file was supposed to import calculator). One of the solutions is using RequireJS.
Include RequireJS while configuring Karma.
It should add (but not install) the package karma-requirejs. Install it along with requirejs by typing: npm install -D requirejs
These packages added 1256 kB, 13 files, 4 folders.
Rewrite calculator.js to the RequireJS format by replacing module.exports = divide with define(() => divide)
Rewrite the test file by replacing const divide = require('../calculator') with define(['calculator'], divide => { ... })
Because I didn’t include the chrome launcher for minimal setup, I had to open the test URL (printed in the console) in a browser manually.

Sample test:

const divide = require('../../calculator');

describe('Divide', () => {

	it('should divide two numbers', () => {
		expect(divide(10, 2)).toBe(5);
	});

	it('unexpected error', () => {
		expect(divide(2, 0)).toBe(0);
	});

});

Mocha

Project: https://www.npmjs.com/package/mocha

Version: 7.0.1

Dependencies: 24

Used in: 7245 npm packages

Source code: 961k uses, 19k stars, 266 issues

Installation:

npm install -D mocha

Size on disk: 6439 kB, 2639 files, 221 folders

Run tests:

mocha

Sample test:

const assert = require('assert');

const divide = require('../calculator');

describe('Divide', () => {

	it('should divide two numbers', () => {
		assert.equal(5, divide(10, 2), '10/2=5');
	});

	it('unexpected error', () => {
		assert.equal(0, divide(2, 0));
	});

});

Mocha + Chai

Chai is an assertion library that can be used with many testing frameworks. However, it’s most commonly used with Mocha. Instead of writing assert.equal(foo, 'bar'), one can write in three styles thanks to Chai:

1. Assert style:

const assert = require('chai').assert;

assert.typeOf(foo, 'string');
assert.equal(foo, 'bar');

2. Expect style (fluent):

const expect = require('chai').expect;

expect(foo).to.be.a('string');
expect(foo).to.equal('bar');

3. Should style (fluent):

const should = require('chai').should;

foo.should.be.a('string');
foo.should.equal('bar');

Project: https://www.npmjs.com/package/chai

Version: 4.2.0

Dependencies: 6

Used in: 6551 npm packages

Source code: 708k uses, 7k stars, 27 issues

Installation:

npm install -D mocha chai

Size on disk: 7317 kB, 2718 files, 233 folders

Run tests:

mocha

Sample test:

const expect = require('chai').expect;

const divide = require('../calculator');

describe('Divide', () => {

	it('should divide two numbers', () => {
		expect(divide(10, 2)).to.equal(5);
	});

	it('unexpected error', () => {
		expect(divide(2, 0)).to.equal(0);
	});

});

Mocha + Chai + Sinon

Sinon is a universal library that provides support for test spies, stubs and mocks. It is compatible with many frameworks. Jasmine and Jest have built-in support for fakes, AVA and Mocha do not, and Sinon is often recommended for Mocha.

Project: https://www.npmjs.com/package/sinon

Version: 8.1.1

Dependencies: 7

Used in: 2228 npm packages

Source code: 301k uses, 8k stars, 30 issues

Installation:

npm install -D mocha chai sinon

Size on disk: 15,990 kB, 2893 files, 270 folders

Run tests:

mocha

Sample test:

const expect = require('chai').expect;
const sinon = require('sinon');

const divide = require('../calculator');

describe('Divide', () => {

	const sandbox = sinon.createSandbox();

	const SUT = {};
	SUT.divide = (a, b) => divide(a, b);
	SUT.half = (a) => SUT.divide(a, 2);

	beforeEach(() => {
		sandbox.spy(SUT, 'divide');
	});

	afterEach(() => {
		sandbox.restore();
	});

	it('was called once', () => {
		SUT.half(10, 2);
		expect(SUT.divide.calledOnce).to.be.ok;
	});

	it('second argument is 2', () => {
		SUT.half(10);
		expect(SUT.divide.firstCall.args[1]).to.equal(2);
	});

	it('unexpected error', () => {
		expect(SUT.divide.calledOnce).to.be.ok;
	});

});

Titef

For comparison, I checked one of the simplest test frameworks. It lacks features, the most burdensome is support for testing only one file, but for simple solutions it should be sufficient.

Project: https://www.npmjs.com/package/titef

Version: 2.2.2

Dependencies: 0

Used in: 0 npm packages

Source code: 1 uses, 14 stars, 5 issues

Installation:

npm install -D titef

Size on disk: 447 kB, 49 files, 31 folders

Run tests:

titef test.js

Sample test:

const assert = require('assert');

const divide = require('../calculator');

suite('Divide', () => {

	spec('should divide two numbers', () => {
		assert.equal(divide(10, 2), 5);
	});

	spec('unexpected error', () => {
		assert.equal(divide(2, 0), 0);
	});

});

Summary

Framework	Size [kB]	Files	Popularity npm	Popularity GitHub
AVA	8141	3002	380	48k
Jest	37230	7211	6557	1.6M
Jasmine	524	108	915	794k
Jasmine + Karma	10165	2494	1029	1.3M
Mocha	6439	2639	7245	961k
Mocha + Chai	7317	2718	6551	708k
Mocha + Chai + Sinon	15990	2893	2228	301k
Titef	447	49	0	1

Łukasz Nojek – blog

Software development and architecture

4 Node.js bloatware testing frameworks: Ava, Jasmine, Jest, Mocha

Category: Dev Toolbox 2020-02-09 Łukasz Nojek

Introduction

AVA

Jest

Jasmine

Jasmine + Karma

Mocha

Mocha + Chai

Mocha + Chai + Sinon

Titef

Summary

Read next