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


Programming language




Unit Testing, Intergration Testing, End-to-End Testing

Unit Testing

General info

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,, wd and Cypress

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
Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.


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


xUnit has the ExUnit framework as an instance
Allows testing code execution on the client, such as a web browser


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.


Front-end code can be tested using ExUnit, Phoenix front-end framework for Elixir uses ExUnit as the default testing framework
Allows testing the bahovior of a server-side code


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


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
Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test

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


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.


Mocha allows grouping of fixtures


Group fixures are possible with this library
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.


Generators are found in the StreamData module
Licence type governing the use and redistribution of the software

MIT License

Apache License 2.0

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)

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


Mocks are available for use with ExUnit through the Mock module. Also available through the use of third party libraries like mecktest
Allows organizing tests in groups


Grouping is supported and is accomplished by the using a nested 'describe()'


Using the 'describe' function which goups tests together. Every describe block recieves a name which is used as a prefix for upcoming tests
Other useful information about the testing framework