Kotest vs Spock comparison of testing frameworks
What are the differences between Kotest and Spock?

	Kotest https://github.com/kotest/kotest	Spock http://spockframework.org/
Programming language	Kotlin	Java
Category	Unit Testing	Unit 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	Spock is a testing and specification framework for Java and Groovy applications Spock has a highly expressive specification language, and due to its JUnit runner, Spock is compatible with most IDEs, build tools, and continuous integration servers.Spock is inspired from JUnit, RSpec, jMock, Mockito, Groovy, Scala, Vulcans among others
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	No	No
Client-side Allows testing code execution on the client, such as a web browser	Yes You can test front-end components with kotest	Yes Spock tests front-end components and functionality by unit testing individual classes and functions
Server-side Allows testing the bahovior of a server-side code	Yes Yes, you can test back-end components with kotest	Yes Spock tests back-end components and functionality by unit testing individual classes and functions
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	Yes Spock contains four methods for setting up environments :setup() (run before every feature method), cleanup() (run after every feature method), setupSpec() (run before the first feature method), cleanupSpec() (run after the last feature method)
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	Yes You can use the fixture methods to setup environments for groups of tests.
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	N/A
Licence Licence type governing the use and redistribution of the software	Apache License 2.0	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 You can use a third party library like mockk to create mocks	Yes Spock has inbuilt mocking capabilities and has no need for external libraries
Grouping Allows organizing tests in groups	Yes You can create test suites with kotest	Yes You can create suites manually in spock
Other Other useful information about the testing framework