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

JUnit

https://junit.org/junit5/

Minitest

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

Java

Ruby

Category

Unit Testing, Regression Testing

Unit Testing

General info

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

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.

Yes

It is an instance of the xUnit architecture for unit testing frameworks.

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

You can test front-end components such as individual classes and functions that create the front-end

No

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

Yes

You can test classes and functions that compose the back-end such as database connections and so on

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

JUnit contains a setUp() method, which runs before every test invocation and a tearDown() method, which runs after every test 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 setUp() and tearDown() inbuilt functions as group fixtures.

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.

You can use JUnit-quickcheck to generate test data

Licence
Licence type governing the use and redistribution of the software

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)

JUnit does not support mocking internally but you can use a mock framework like Mockito to generate mock objects.

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

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.

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