Kotest vs testdouble.js comparison of testing frameworks
What are the differences between Kotest and testdouble.js?

Kotest

https://github.com/kotest/kotest

testdouble.js

https://github.com/testdouble/testdouble.js
Programming language

Kotlin

JavaScript

Category

Unit Testing

Unit Testing, Intergration Testing

General info

kotest is a powerful, elegant and flexible test framework for Kotlin, formerly known as kotlintest

Kotest has excellent support for data driven testing or table driven testing where it has the ability to quickly rerun the same test over and over with a predefined set of inputs and expected values

This library was designed to work for both Node.js and browser interpreters and it encourages the TDD (Test Driven Development)

Test doubles can be used with conjuction of other test frameworks such as Jasmine, Jest, Chai, QUnit, Mocha, Tape etc.
xUnit
Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.

No

Yes

It is compatible with xUnit and supportsxUnit XML output
Client-side
Allows testing code execution on the client, such as a web browser

Yes

You can test front-end components with kotest

No

Server-side
Allows testing the bahovior of a server-side code

Yes

Yes, you can test back-end components with kotest

Yes

Testdouble is primarily used to test server-side functions, behaviours and components
Fixtures
Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test

Yes

kotest contains fixtures, that is the setup / teardown functions

N/A

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

kotest has group fixtures available

N/A

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

Apache License 2.0

MIT 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)

Yes

You can use a third party library like mockk to create mocks

Yes

Testdouble includes inbuilt support for mocking
Grouping
Allows organizing tests in groups

Yes

You can create test suites with kotest

N/A

Other
Other useful information about the testing framework