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

	Chai https://www.chaijs.com	ExUnit https://hexdocs.pm/ex_unit/ExUnit.html
Programming language	JavaScript	Elixir
Category	Unit Testing	Unit Testing
General info	Chai is a BDD / TDD assertion library for Node.js and the browser that can be paired with any JavaScript testing framework. Chai is an assertion library, similar to Node's built-in assert and makes testing easier by giving you many assertions you can run against your code. It also includes a robust Plugin architecture for extending Chai's assertions and interfaces.	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.	N/A	Yes xUnit has the ExUnit framework as an instance
Client-side Allows testing code execution on the client, such as a web browser	Yes Chai can be used in a browser environment to test front-end components and functionality	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 Chai is used in a Node.JS environment to test server behaviour and functionality	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	N/A	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.	N/A	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 By using chai-spec-generator plugin which will generate chai test specs from a JavaScript object	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 By using by using a third party library like chai-jest-mocks which is a chai plugin that adds assertions for jest mock functions. You can also use sinon.js	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	N/A	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