Support XCSkipTests under Mac Catalyst

Package.swift

@@ -21,7 +21,7 @@ let package = Package(
         .plugin(name: "skipstone", capability: .buildTool(), dependencies: ["skip"], path: "Plugins/SkipPlugin"),
         .plugin(name: "Create SkipLink", capability: .command(intent: .custom(verb: "SkipLink", description: "Create local links to transpiled output"), permissions: [.writeToPackageDirectory(reason: "This command will create local links to the skipstone output for the specified package(s), enabling access to the transpiled Kotlin")]), dependencies: ["skip"], path: "Plugins/SkipLink"),
         .target(name: "SkipDrive", dependencies: ["skipstone", .target(name: "skip")]),
-        .target(name: "SkipTest", dependencies: [.target(name: "SkipDrive", condition: .when(platforms: [.macOS, .linux]))]),
+        .target(name: "SkipTest", dependencies: [.target(name: "SkipDrive", condition: .when(platforms: [.macOS, .macCatalyst, .linux]))]),
         .testTarget(name: "SkipTestTests", dependencies: ["SkipTest"]),
         .testTarget(name: "SkipDriveTests", dependencies: ["SkipDrive"]),
     ]

Sources/SkipDrive/GradleDriver.swift

@@ -715,7 +715,7 @@ extension ProcessInfo {
         }
 
         // “The script installs Homebrew to its default, supported, best prefix (/opt/homebrew for Apple Silicon, /usr/local for macOS Intel and /home/linuxbrew/.linuxbrew for Linux)” — https://docs.brew.sh/Installation
-        #if os(macOS) || os(macCatalyst)
+        #if os(macOS) || targetEnvironment(macCatalyst)
         return ProcessInfo.isARM ? "/opt/homebrew" : "/usr/local"
         #else
         // Linux
@@ -728,7 +728,7 @@ extension ProcessInfo {
         var env = self.environment
         let ANDROID_HOME = "ANDROID_HOME"
         if (env[ANDROID_HOME] ?? "").isEmpty {
-            #if os(macOS)
+            #if os(macOS) || targetEnvironment(macCatalyst)
             env[ANDROID_HOME] = ("~/Library/Android/sdk" as NSString).expandingTildeInPath
             #elseif os(Windows)
             env[ANDROID_HOME] = ("~/AppData/Local/Android/Sdk" as NSString).expandingTildeInPath
@@ -745,7 +745,7 @@ extension ProcessInfo {
 
         let JAVA_HOME = "JAVA_HOME"
         if (env[JAVA_HOME] ?? "").isEmpty {
-            #if os(macOS)
+            #if os(macOS) || targetEnvironment(macCatalyst)
             // default if JAVA_HOME is unset: /opt/homebrew/opt/java -> ../Cellar/openjdk/21.0.1
             env[JAVA_HOME] = "\(Self.homebrewRoot)/opt/java"
             #endif

Sources/SkipDrive/ToolSupport.swift

@@ -112,7 +112,7 @@ extension Process {
 extension ProcessInfo {
     /// True when the current architecture is ARM
     public static let isARM = {
-        #if os(macOS)
+        #if os(macOS) || targetEnvironment(macCatalyst)
         var size: size_t = 0
         sysctlbyname("hw.machine", nil, &size, nil, 0)
         var machine = [CChar](repeating: 0, count: size)
@@ -986,8 +986,8 @@ fileprivate final class PendingResultBox: @unchecked Sendable {
             // we could do something like this:
             // https://github.com/swiftlang/swift-tools-support-core/pull/113/changes
             //
-            // but for now we simple ignore workingDirectory flag on Linux
-            #if !os(Linux)
+            // but for now we simply ignore workingDirectory flag on Linux and Mac Catalyst.
+            #if !os(Linux) && !targetEnvironment(macCatalyst)
             posix_spawn_file_actions_addchdir_np(&fileActions, workingDirectory)
             #endif
         }

Sources/SkipTest/XCGradleHarness.swift

@@ -2,7 +2,7 @@
 #if !SKIP
 #if canImport(SkipDrive)
 import SkipDrive
-#if os(macOS) || os(Linux)
+#if os(macOS) || targetEnvironment(macCatalyst) || os(Linux)
 @_exported import XCTest
 
 /// A `XCTestCase` that invokes the `gradle` process.
@@ -42,7 +42,7 @@ extension XCGradleHarness where Self : XCTestCase {
                 }
                 return raw.split(separator: "\n", omittingEmptySubsequences: true).map(String.init)
             }()
-            try await invokeGradle(actions: [testAction], info: info, deviceID: device, testFilters: testFilters)
+            try await invokeGradle(actions: [testAction], info: info, deviceID: device, testFilters: testFilters, fromSourceFileRelativeToPackageRoot: file)
             print("Completed gradle test run for \(device ?? "local")")
         } catch {
             XCTFail("\((error as? LocalizedError)?.localizedDescription ?? error.localizedDescription)", file: file, line: line)
@@ -99,6 +99,21 @@ extension XCGradleHarness where Self : XCTestCase {
                 var testProcessResult: ProcessResult? = nil
 
                 var env: [String: String] = ProcessInfo.processInfo.environmentWithDefaultToolPaths
+                #if targetEnvironment(macCatalyst)
+                if let packageRootURL = sourcePath.flatMap(packageBaseFolder(forSourceFile:)) {
+                    // Robolectric runs in a macOS JVM, so build host dylibs instead of loading Catalyst frameworks.
+                    let configuration = actions.contains(where: { $0.localizedCaseInsensitiveContains("release") }) ? "release" : "debug"
+                    let swiftBuildArgs = ["/usr/bin/xcrun", "swift", "build", "--package-path", packageRootURL.path, "--target", baseModuleName, "--configuration", configuration, "--disable-sandbox"]
+                    try await Process.checkNonZeroExit(arguments: swiftBuildArgs, environment: env)
+                    let arch = ProcessInfo.isARM ? "arm64-apple-macosx" : "x86_64-apple-macosx"
+                    env["SKIP_FFI_LIBRARY_PATH"] = packageRootURL
+                        .appendingPathComponent(".build", isDirectory: true)
+                        .appendingPathComponent(arch, isDirectory: true)
+                        .appendingPathComponent(configuration, isDirectory: true)
+                        .path
+                }
+                #endif
+
                 if let deviceID = deviceID, !deviceID.isEmpty {
                     env["ANDROID_SERIAL"] = deviceID
                 }
@@ -576,6 +591,6 @@ extension XCTestCase {
 #endif
 
 
-#endif // os(macOS) || os(Linux)
+#endif // os(macOS) || targetEnvironment(macCatalyst) || os(Linux)
 #endif // canImport(SkipDrive)
 #endif // !SKIP