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

ExUnit

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

Mocha

https://mochajs.org
Programming language

Elixir

JavaScript

Category

Unit Testing

Unit Testing, Intergration Testing, End-to-End 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

Mocha is a widely used JavaScript test framework for Node.js

Mocha is a simple, flexible and the one of the widely adopted JS test framework. Mocha usually runs tests serially which enables the accurate reporting. Also it's useful for asynchronous testing, and provides various king of test reports. Spec is default test reporter for mocha, there are many test reports like Nyan, Dot matrix, Tap, Landing strip, List and Progress. Mocha is being used with many other test frameworks like Selenium WebDriver, Webdriver.io, wd and Cypress
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

It has an XUnit reporter available which outputs an XUnit-compatible XML document, often applicable in CI servers.
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

Mocha Runs in the browser and is used widely to test front-end components and functionality. It can test various DOM elements, front-end functions and so on.
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

Mocha provides convenient ways of testing the Node server.It works well with Chai (an assertion library) where it provides the environment for writing server-side tests while we write the tests with Chai
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

Mocha provides the hooks before(), after(), beforeEach(), and afterEach() to set up preconditions and clean up after your tests
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

N/A

Mocha allows grouping of 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

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

Provides Mocking capabilities through third party libraries like sinon.js, simple-mock and nock
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

Grouping is supported and is accomplished by the using a nested 'describe()'
Other
Other useful information about the testing framework