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

	testdouble.js https://github.com/testdouble/testdouble.js	Kotest https://github.com/kotest/kotest
Programming language	JavaScript	Kotlin
Category	Unit Testing, Intergration Testing	Unit Testing
General info	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.	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
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	Yes It is compatible with xUnit and supportsxUnit XML output	No
Client-side Allows testing code execution on the client, such as a web browser	No	Yes You can test front-end components with kotest
Server-side Allows testing the bahovior of a server-side code	Yes Testdouble is primarily used to test server-side functions, behaviours and components	Yes Yes, you can test back-end components with kotest
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 kotest contains fixtures, that is the setup / teardown functions
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 kotest has group fixtures available
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	MIT License	Apache License 2.0
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 Testdouble includes inbuilt support for mocking	Yes You can use a third party library like mockk to create mocks
Grouping Allows organizing tests in groups	N/A	Yes You can create test suites with kotest
Other Other useful information about the testing framework