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

Quick

https://github.com/quick/quick

XCTest

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

Swift

Swift

Category

Acceptance Testing, Unit Testing

Unit Testing, Performance Testing

General info

Quick is a Swift (and Objective-C) testing framework.

Quick is a behavior-driven development framework for Swift and Objective-C that is inspired by RSpec, Specta, and Ginkgo. Quick comes bundled with Nimble a matcher framework for your tests.

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.

Yes

Yes, it is an xUnit style test framework

Yes

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

Yes

Developers can test front-end behaviour and components by defining front-end feature specifications

Yes

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

Yes

Developers can test back-end behaviour and components by defining back-end feature specifications

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

Quick contains fixture methods setup() and teardown() for setting up and destroying test environments

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

Yes, example groups (logical groupings of examples/tests) can share setup and teardown code

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

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

Yes, developers can create mock objects with Quick using the Cuckoo library

Yes

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

Yes

In Quick test suites are named Specs, and every test suite you create starts off with a class inheriting from QuickSpec includes a main method, spec() which contains all the test cases.

Yes

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