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

Spock

http://spockframework.org/

Minitest

https://github.com/seattlerb/minitest
Programming language

Java

Ruby

Category

Unit Testing

Unit Testing

General info

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

Complete suite of testing facilities

Minitest is small, fast, and it aims to make tests clean and readable. It supports test-driven development (TDD), behavior-driven development (BDD), mocking, and benchmarking.
xUnit
Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.

No

Yes

MiniTest is an xUnit style framework in that is has assertion functions in the style of xUnit/TDD
Client-side
Allows testing code execution on the client, such as a web browser

Yes

Spock tests front-end components and functionality by unit testing individual classes and functions

No

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

Yes

Spock tests back-end components and functionality by unit testing individual classes and functions

Yes

You can test various back-end components
Fixtures
Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test

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)

Yes

Minitest supports test fixture 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.

Yes

You can use the fixture methods to setup environments for groups of tests.

Yes

Minitest has 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

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

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

Yes

Mocking is available through the Minitest::Mock class which is a simple and clean mock object framework
Grouping
Allows organizing tests in groups

Yes

You can create suites manually in spock

Yes

Allows grouping by nested Ruby classes. RSpec-like "context" method is available for spec syntax through the minitest-spec-context extension gem
Other
Other useful information about the testing framework