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

	Unit.js https://unitjs.com/	Cucumber https://github.com/cucumber/cucumber-ruby
Programming language	JavaScript	Ruby
Category	Unit Testing, End-to-End Testing	Acceptance Testing
General info	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.	An automation tool for Behavior-Driven Development The specifications are written in plain texts, which allows them to be easily understandable for all stakeholders. Cucumber Framework also supports languages beyond Ruby e.g. Java, JavaScript and Scala.
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	Yes Unit.js runs in the browser to test front-end components	Yes You can test the front-end part like the GUI using cucumber and selenium, they integrate well to test your front-end.
Server-side Allows testing the bahovior of a server-side code	Yes Unit.js runs in nodejs to test server-side behaviour	Yes You can test back-end components such as APIs using rest & soap clients, and databases using whatever client libraries were provided by the libraries that existed in those stacks
Fixtures Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test	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.	Yes With Unit.js you can group your fixtures	Yes Using the cucumber extension aruba you can create fixures in two steps: 1.Create a fixtures-directory; 2.Create fixture files in this directory
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 You can group your fixtures inside your fixtures directories
Licence Licence type governing the use and redistribution of the software	GNU	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)	N/A	Yes By using all of RSpec’s supported mocking frameworks (RSpec, Mocha, RR, Flexmock)
Grouping Allows organizing tests in groups	N/A	Yes Cucumber allows the use of tag Cucumber feature files or individual tests to group tests. Then, you can pass a Cucumber tagged expression at test execution that specifies the tag (grouped) tests to run. https://www.toolsqa.com/cucumber/cucumber-tags/
Other Other useful information about the testing framework