RSpec vs ExUnit comparison of testing frameworks
What are the differences between RSpec and ExUnit?

	RSpec https://rspec.info	ExUnit https://hexdocs.pm/ex_unit/ExUnit.html
Programming language	Ruby	Elixir
Category	Unit Testing, Intergration Testing	Unit Testing
General info	Domain Specific Language (DSL) testing solution for Ruby code It focuses on empowering Test Driven Development (TDD). RSpec contains multiple smaller libraries, which may be independently used with other testing frameworks.	Unit testing framework for Elixir. Elixir comes bundled with ExUnit allowing developers to use all elixir features without compromising unit tests. It uses a TDD workflow, and shows one message per test
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	Yes Yes, but it differs from more traiditional xUnit solutions. Its tests are written in a "Tests as Specification" manner. This means that the terminology used in RSpec is adjusted to a language more fitting for specification.	Yes xUnit has the ExUnit framework as an instance
Client-side Allows testing code execution on the client, such as a web browser	Yes RSpec is used to primarily test the behaviour of applications or individual components so it can test front-end behaviour as well - you can use capybara gem with RSpec for that.	Yes Front-end code can be tested using ExUnit, Phoenix front-end framework for Elixir uses ExUnit as the default testing framework
Server-side Allows testing the bahovior of a server-side code	Yes You can test server-side behaviour with Rspec	Yes ExUnit tests backend code. Typically Unit tests will be written not to interact with the browser, but with ExUnit you can test whichever part of your application
Fixtures Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test	Yes RSpec does contain fixture methods	Yes ExUnit has a library called ExUnitFixtures fixtures are functions that are run before a test is run to setup the test environment or provide the test with data
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 Group fixture methods are supported	Yes Group fixures are possible with this library
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.	Yes RSpec contains generators for example intergration_'test_name' which will save a spec inside the spec/requests folder	Yes Generators are found in the StreamData module
Licence Licence type governing the use and redistribution of the software	MIT 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 Available through rspec-mocks gem.	Yes Mocks are available for use with ExUnit through the Mock module. Also available through the use of third party libraries like mecktest
Grouping Allows organizing tests in groups	Yes Allows declaring example groups and contexts.	Yes Using the 'describe' function which goups tests together. Every describe block recieves a name which is used as a prefix for upcoming tests
Other Other useful information about the testing framework