Unit.js vs Spek comparison of testing frameworks
What are the differences between Unit.js and Spek?

	Unit.js https://unitjs.com/	Spek https://www.spekframework.org/
Programming language	JavaScript	Kotlin
Category	Unit Testing, End-to-End Testing	Acceptance Testing, Unit Testing
General info	An assertion library for JavaScript (similar to chai.js) It works with any test runner and unit testing framework like Mocha, Jasmine, Karma, protractor (E2E test framework for Angular apps) and QUnit.	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.		No
Client-side Allows testing code execution on the client, such as a web browser	Yes Unit.js runs in the browser to test front-end components	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 Unit.js runs in nodejs to test server-side behaviour	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	Yes Unit.js provides Test fixtures for running testsThis is one of its features	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.	Yes With Unit.js you can group your fixtures	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	GNU	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)	N/A	Yes You can use the third party library mockito-kotlin
Grouping Allows organizing tests in groups	N/A	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