Xcode: TEST vs DEBUG preprocessor macros

Question

When creating a new project with unit tests, Xcode sets the build configuration to Debug for the Test scheme (same for the Run scheme).

Should I differentiate betwee

Answer 1

Preprocessor macros will not work, you need to check the environment at runtime.

Objective-c

static BOOL isRunningTests(void)
{
    NSDictionary* environment = [[NSProcessInfo processInfo] environment];
    return (environment[@"XCTestConfigurationFilePath"] != nil);
}

Swift

var unitTesting : Bool 
{
    return ProcessInfo.processInfo.environment["XCTestConfigurationFilePath"] != nil
}

(Updated for Xcode 11)