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

XCTest

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

Kotest

https://github.com/kotest/kotest
Programming language

Swift

Kotlin

Category

Unit Testing, Performance Testing

Unit 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.

kotest is a powerful, elegant and flexible test framework for Kotlin, formerly known as kotlintest

Kotest has excellent support for data driven testing or table driven testing where it has the ability to quickly rerun the same test over and over with a predefined set of inputs and expected values
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

No

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

Yes

Developers can test individual front-end components with XCTest

Yes

You can test front-end components with kotest
Server-side
Allows testing the bahovior of a server-side code

Yes

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

Yes

Yes, you can test back-end components with kotest
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

Yes

kotest contains fixtures, that is the setup / teardown functions
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

Yes

kotest has group fixtures available
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

Apache License 2.0

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)

Yes

You can create protocol mocks and class mocks with libraries such as MockFive or Cuckoo

Yes

You can use a third party library like mockk to create mocks
Grouping
Allows organizing tests in groups

Yes

Developers can define test suites from the XCTestSuite class

Yes

You can create test suites with kotest
Other
Other useful information about the testing framework