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

Spek

https://www.spekframework.org/

Spock

http://spockframework.org/
Programming language

Kotlin

Java

Category

Acceptance Testing, Unit Testing

Unit 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.

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

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

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

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

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

Fixtures are available in spek through functions suchas beforeEachTest() and afterEachTest()

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

spek has group fixtures available through the beforeGroup() and afterGroup() functions

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

Modified BSD 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

You can use the third party library mockito-kotlin

Yes

Spock has inbuilt mocking capabilities and has no need for external libraries
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

You can create suites manually in spock
Other
Other useful information about the testing framework