XCTest vs testdouble.js comparison of testing frameworks
What are the differences between XCTest and testdouble.js?

	XCTest https://developer.apple.com/documentation/xctest	testdouble.js https://github.com/testdouble/testdouble.js
Programming language	Swift	JavaScript
Category	Unit Testing, Performance Testing	Unit Testing, Intergration Testing
General info	XCTest is the default testing framework for unit tests, performance tests, and some level of UI tests for iOS apps. XCTest framework is a testing framework that enables developers write basic unit tests, performance tests, and some level of UI tests for iOS apps.	This library was designed to work for both Node.js and browser interpreters and it encourages the TDD (Test Driven Development) Test doubles can be used with conjuction of other test frameworks such as Jasmine, Jest, Chai, QUnit, Mocha, Tape etc.
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	Yes Yes, it is an xUnit style framework	Yes It is compatible with xUnit and supportsxUnit XML output
Client-side Allows testing code execution on the client, such as a web browser	Yes Developers can test individual front-end components with XCTest	No
Server-side Allows testing the bahovior of a server-side code	Yes Yes, developers can test individual back-end components with XCTest	Yes Testdouble is primarily used to test server-side functions, behaviours and components
Fixtures Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test	Yes XCTest contains setup() and teardown() fixture methods for setting up and destroying test environments	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 fixtures are available in XCTest	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.	N/A
Licence Licence type governing the use and redistribution of the software	Apache License 2.0	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)	Yes You can create protocol mocks and class mocks with libraries such as MockFive or Cuckoo	Yes Testdouble includes inbuilt support for mocking
Grouping Allows organizing tests in groups	Yes Developers can define test suites from the XCTestSuite class	N/A
Other Other useful information about the testing framework