Test::Unit vs Chai comparison of testing frameworks
What are the differences between Test::Unit and Chai?

Test::Unit

https://test-unit.github.io/

Chai

https://www.chaijs.com
Programming language

Ruby

JavaScript

Category

Unit Testing, Intergration Testing

Unit Testing

General info

Test::Unit is a unit testing framework for Ruby

Test::Unit is an implementation of the xUnit testing framework for ruby which is used for Unit Testing. However Test::Unit has been left in the standard library to support legacy test suites therefore if you are writing new test code use Minitest instead of Test::Unit

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

Yes

test-unit is a xUnit family unit testing framework for Ruby

N/A

Client-side
Allows testing code execution on the client, such as a web browser

It could have tested some front-end components but its now legacy hence wouldn't work with the many new front-end components

Yes

Chai can be used in a browser environment to test front-end components and functionality
Server-side
Allows testing the bahovior of a server-side code

Yes

Yes

Chai is used in a Node.JS environment to test server behaviour and functionality
Fixtures
Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test

Yes

Fixture methods are available through its ClassMethods Module

N/A

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 fixture methods are supported

N/A

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.

No

Yes

By using chai-spec-generator plugin which will generate chai test specs from a JavaScript object
Licence
Licence type governing the use and redistribution of the software

LGPLv2.1, Ruby Licence

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)

No

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
Grouping
Allows organizing tests in groups

No

N/A

Other
Other useful information about the testing framework