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

ExUnit

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

Behat

https://docs.behat.org/en/latest/
Programming language

Elixir

PHP

Category

Unit Testing

Functional/Acceptance 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

Behat is an open source Behavior-Driven Development framework for PHP.

Behat uses the StoryBDD subtype of behaviour-driven development (the other subtype is SpecBDD); This means the tests we write with Behat look rather like stories than code. It is inspired by Ruby's Cucumber
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

No

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

To enable Behat to test a website, you need to add Mink and a browser emulator (selenium maybe, though slow) to the mix. Mink methods are the connector between Behat and an extensive list of available drivers, and they provide a consistent testing API.
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

Behat can be used for Data Integrity Testing to verify that database operations are functioning properly
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

Yes

One can use the 'Doctrinefixturesbundle' to create the required fixture loaders and load them in our Behat scenarios when required, using the 'BeforeScenario' hook.
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

Behat allows for 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.

Yes

Generators are found in the StreamData module

By use of third party libraries like moodle-behat-generators
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

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

By using third party libraries like Mock and Prophecy
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

You can use tags to group features and scenarios together, independent of your file and directory structure
Other
Other useful information about the testing framework