Spek vs JUnit comparison of testing frameworks
What are the differences between Spek and JUnit?

	Spek https://www.spekframework.org/	JUnit https://junit.org/junit5/
Programming language	Kotlin	Java
Category	Acceptance Testing, Unit Testing	Unit Testing, Regression Testing
General info	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.	JUnit is an open source Unit testing framework for java JUnit is useful for developers to write and run repeatable tests. JUnit has been crucial in the development of test driven development and is partof the xUnit family of unit testing frameworks
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	No	Yes It is an instance of the xUnit architecture for unit testing frameworks.
Client-side Allows testing code execution on the client, such as a web browser	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.	Yes You can test front-end components such as individual classes and functions that create the front-end
Server-side Allows testing the bahovior of a server-side code	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	Yes You can test classes and functions that compose the back-end such as database connections and so on
Fixtures Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test	Yes Fixtures are available in spek through functions suchas beforeEachTest() and afterEachTest()	Yes JUnit contains a setUp() method, which runs before every test invocation and a tearDown() method, which runs after every test 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 spek has group fixtures available through the beforeGroup() and afterGroup() functions	Yes You can use setUp() and tearDown() inbuilt functions as group fixtures.
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	You can use JUnit-quickcheck to generate test data
Licence Licence type governing the use and redistribution of the software	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)	Yes You can use the third party library mockito-kotlin	JUnit does not support mocking internally but you can use a mock framework like Mockito to generate mock objects.
Grouping Allows organizing tests in groups	Yes Tests are written using nested lambdas, each scope (level) can either be a group or a test	Yes In JUnit you can create a test suite that bundles a few unit test cases and runs them together. You use both @RunWith and @Suite annotation are used to run the suite test.
Other Other useful information about the testing framework