Shoulda vs XCTest comparison of testing frameworks
What are the differences between Shoulda and XCTest?

Shoulda

https://github.com/thoughtbot/shoulda

XCTest

https://developer.apple.com/documentation/xctest
Programming language

Ruby

Swift

Category

Unit Testing, Performance 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.

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

No

Yes

Yes, it is an xUnit style framework
Client-side
Allows testing code execution on the client, such as a web browser

N/A

Yes

Developers can test individual front-end components with XCTest
Server-side
Allows testing the bahovior of a server-side code

N/A

Yes

Yes, developers can test individual back-end components with XCTest
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

XCTest contains setup() and teardown() fixture methods for setting up and destroying test environments
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 fixtures are available in XCTest
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

N/A

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)

N/A

Yes

You can create protocol mocks and class mocks with libraries such as MockFive or Cuckoo
Grouping
Allows organizing tests in groups

Yes

Yes

Developers can define test suites from the XCTestSuite class
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.