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

ExUnit

https://hexdocs.pm/ex_unit/ExUnit.html

Kiwi

https://github.com/kiwi-bdd/Kiwi
Programming language

Elixir

Swift

Category

Unit Testing

Unit Testing

General info

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

Kiwi is a Behavior Driven Development library for iOS development

The goal behind Kiwi is to provide a BDD library that is simple to setup and use, and create tests that are more readable than what is possible with the bundled test framework.
xUnit
Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.

Yes

xUnit has the ExUnit framework as an instance

Yes

Kiwi is an xUnit style framework
Client-side
Allows testing code execution on the client, such as a web browser

Yes

Front-end code can be tested using ExUnit, Phoenix front-end framework for Elixir uses ExUnit as the default testing framework

Yes

You can test front-end components with kiwi
Server-side
Allows testing the bahovior of a server-side code

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

Yes

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

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 fixures are possible with this library

Yes

kiwi has a beforeEach(aBlock) which is run before every 'it' block in all enclosed contexts. Code that sets up the particular context should go here and afterEach(aBlock) which is run after every it block in all enclosed contexts
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

Generators are found in the StreamData module

Yes

through the beforeAll(aBlock) and afterAll(aBlock) functions.
Licence
Licence type governing the use and redistribution of the software

Apache License 2.0

Proprietary, Open source

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

Mocks are available for use with ExUnit through the Mock module. Also available through the use of third party libraries like mecktest

Yes

Kiwi has inbuilt support for stubs and mocks,including null mocks, class mocks, protocol mocks
Grouping
Allows organizing tests in groups

Yes

Using the 'describe' function which goups tests together. Every describe block recieves a name which is used as a prefix for upcoming tests

Yes

Kiwi uses the block syntax in iOS to define groups of assertions and share setup state between collections of tests
Other
Other useful information about the testing framework