Using XCTest
Your tests are organized into a simple hierarchy. Each XCTestCase subclass has a set of test methods, each of which should test one part of your code.
For general information about using XCTest, see:
Using XCTest with Swift Package Manager
The Swift Package Manager integrates directly with XCTest to provide a streamlined experience for unit testing SwiftPM packages. If you are using XCTest within a SwiftPM package, unit test files are located within the package’s Tests subdirectory, and you can build and run the full test suite in one step by running swift test.
For more information about using XCTest with SwiftPM, see its documentation.