Shoulda vs Unit.js comparison of testing frameworks
What are the differences between Shoulda and Unit.js?

Shoulda

https://github.com/thoughtbot/shoulda

Unit.js

https://unitjs.com/
Programming language

Ruby

JavaScript

Category

Unit Testing, End-to-End Testing

General info

Meta gem containing Shoulda Context and Shoulda Matchers

Shoulda contains two other gems: Should Context and Shoulda Matchers. Should Context allows better naming and grouping of your tests. Shoulda Matchers provides a set of "matchers", i.e. methods that allow you to write much more concise assertions.

An assertion library for JavaScript (similar to chai.js)

It works with any test runner and unit testing framework like Mocha, Jasmine, Karma, protractor (E2E test framework for Angular apps) and QUnit.
xUnit
Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.

No

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

N/A

Yes

Unit.js runs in the browser to test front-end components
Server-side
Allows testing the bahovior of a server-side code

N/A

Yes

Unit.js runs in nodejs to test server-side behaviour
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

Unit.js provides Test fixtures for running testsThis is one of its features
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

With Unit.js you can group your 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.

N/A

Licence
Licence type governing the use and redistribution of the software

MIT License

GNU

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)

N/A

N/A

Grouping
Allows organizing tests in groups

Yes

N/A

Other
Other useful information about the testing framework

Shoulda Context is compatible with Minitest and Test::Unit. Shoulda Matchers is compatible with RSpec and Minitest.