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

Spek

https://www.spekframework.org/

XCTest

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

Kotlin

Swift

Category

Acceptance Testing, Unit Testing

Unit Testing, Performance Testing

General info

Spek is a specification framework for Kotlin

Spek is a Kotlin-based Specification Testing framework for the JVM. It works as a JUnit 5 Test Engine meaning that we can easily plug it into any project that already uses JUnit 5 to run alongside any other tests that we might have.

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

Yes

Yes you can test front-end behaviour by writing specifications to test front-end functionality. Developers can also write unit tests for individual front-end components.

Yes

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

Yes

You can test back-end behaviour and componets by writing specifications to test back-end functionality and unit tests for individual back-end components

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

Yes

Fixtures are available in spek through functions suchas beforeEachTest() and afterEachTest()

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.

Yes

spek has group fixtures available through the beforeGroup() and afterGroup() functions

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

Modified BSD 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)

Yes

You can use the third party library mockito-kotlin

Yes

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

Yes

Tests are written using nested lambdas, each scope (level) can either be a group or a test

Yes

Developers can define test suites from the XCTestSuite class
Other
Other useful information about the testing framework