XCTEST

Swift Testing and XCTest

At WWDC 2024, Apple introduced Swift Testing as a new testing framework that offers several enhancements over XCTest. Here are some key points about Swift Testing:

1. Test Functions: In Swift Testing, test functions are explicitly marked with the @Test attribute, unlike XCTest where test methods must start with the word "test". This allows for more flexibility in naming and structuring tests.

2. Expectations and Assertions: Swift Testing uses two basic macros, expect and require, for assertions, simplifying the process compared to XCTest's multiple XCTAssert functions. The require macro can be used to halt a test upon failure.

3. Parallel Testing: Swift Testing runs tests in parallel by default, which can significantly reduce execution time, especially in CI environments. This is a departure from XCTest, which supports parallelization only through multiple processes.

4. Suite Types: Swift Testing supports structs, actors, and classes for test suites, promoting value semantics and reducing bugs from state sharing. XCTest, on the other hand, only supports classes that inherit from XCTestCase.

5. Migration: Swift Testing and XCTest can coexist, allowing for incremental migration. Swift Testing is open source and works across all Apple platforms, as well as Linux and Windows, ensuring consistent behavior across different environments.

For more detailed information, you can refer to the session Meet Swift Testing (17:35) which discusses the relationship between Swift Testing and XCTest.