Buster.JS vs Spek comparison of testing frameworks
What are the differences between Buster.JS and Spek?

Buster.JS

https://busterjs.readthedocs.io

Spek

https://www.spekframework.org/
Programming language

JavaScript

Kotlin

Category

Unit Testing, Browser Automation

Acceptance Testing, Unit Testing

General info

Buster.JS is a JavaScript test framework for node and browsers.

Buster.JS is a new JavaScript testing framework. It does browser testing by automating test runs in actual browsers (think JsTestDriver), as well as Node.js testing. It has a bunch of great features.

Spek is a specification framework for Kotlin

Spek is a Kotlin-based Specification Testing framework for the JVM. It works as a JUnit 5 Test Engine meaning that we can easily plug it into any project that already uses JUnit 5 to run alongside any other tests that we might have.
xUnit
Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.

Yes

Buster.Js is a xUnit style Test Framework

No

Client-side
Allows testing code execution on the client, such as a web browser

Yes

It does browser testing with browser automation, QUnit style static HTML page testing, testing in headless browsers and more front-end components and functionality

Yes

Yes you can test front-end behaviour by writing specifications to test front-end functionality. Developers can also write unit tests for individual front-end components.
Server-side
Allows testing the bahovior of a server-side code

Yes

It is a Node.js testing toolkit as well which means it can test back-end behaviour and functionality as well as run in a server environment

Yes

You can test back-end behaviour and componets by writing specifications to test back-end functionality and unit tests for individual back-end components
Fixtures
Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test

N/A

Yes

Fixtures are available in spek through functions suchas beforeEachTest() and afterEachTest()
Group fixtures
Allows defining a fixed, specific states of data for a group of tests (group-fixtures). This ensures specific environment for a given group of tests.

N/A

Yes

spek has group fixtures available through the beforeGroup() and afterGroup() functions
Generators
Supports data generators for tests. Data generators generate input data for test. The test is then run for each input data produced in this way.

N/A

Licence
Licence type governing the use and redistribution of the software

BSD License

Modified BSD License

Mocks
Mocks are objects that simulate the behavior of real objects. Using mocks allows testing some part of the code in isolation (with other parts mocked when needed)

Buster.JS ships with Sinon.JS. every test in a test case has a sandbox associated with it, making it easy to mock and stub

Yes

You can use the third party library mockito-kotlin
Grouping
Allows organizing tests in groups

Yes

Tests are written using nested lambdas, each scope (level) can either be a group or a test
Other
Other useful information about the testing framework