Fix compilation on platforms without Foundation.Process (#1209)

### Motivation: There's an open PR to add CI for Apple platforms. This is currently failing since it tries to build for all Apple platforms, not just macOS. This is because there are targets that provide support for testing that rely on `Foundation.process`, which is unavailable on non-macOS Apple platforms. ### Modifications: Guard the use of `Foundation.Process` with an `#if canImport`. ### Result: Package builds for non-macOS Apple platforms: iOS, tvOS, watchOS, etc.

Author: simonjbeaumont

Sources/DistributedActorsTestKit/InspectKit.swift

@@ -22,6 +22,7 @@ internal struct InspectKit {
  FileManager.default.currentDirectoryPath
  }
 
+ #if canImport(Foundation.Process)
  private static func runCommand(cmd: String, args: String...) -> (output: [Substring], error: [Substring], exitCode: Int32) {
  var output: [Substring] = []
  var error: [Substring] = []
@@ -54,6 +55,7 @@ internal struct InspectKit {
 
  return (output, error, status)
  }
+ #endif
 
  struct ActorStats {
  var stats: [String: Row] = [:]
@@ -144,6 +146,10 @@ internal struct InspectKit {
 
  /// Actor names to their counts
  static func actorStats() throws -> ActorStats {
+ #if !canImport(Foundation.Process)
+ struct UnsupportedPlatform: Error {}
+ throw UnsupportedPlatform()
+ #else
  // FIXME(regex): rdar://98705227 can't use regex on 5.7 on Linux because of a bug that crashes String.starts(with:) at runtime then
  let (out, err, _) = Self.runCommand(cmd: "\(self.baseDir)/scripts/dump_actors.sh")
 
@@ -172,11 +178,13 @@ internal struct InspectKit {
  }
 
  return ActorStats(stats: stats)
+ #endif
  }
 }
 
 extension [Substring: InspectKit.ActorStats] {}
 
+#if canImport(Foundation.Process)
 // Compatible with Swift on all macOS versions as well as Linux
 extension Process {
  var binaryPath: String? {
@@ -204,3 +212,4 @@ extension Process {
  }
  }
 }
+#endif

Sources/MultiNodeTestKitRunner/Process+Extensions.swift

@@ -18,9 +18,13 @@ import NIOCore
 import NIOPosix
 
 import class Foundation.FileHandle
-import class Foundation.Process
 import struct Foundation.URL
 
+#if canImport(Foundation.Process)
+import class Foundation.Process
+#endif
+
+#if canImport(Foundation.Process)
 // Compatible with Swift on all macOS versions as well as Linux
 extension Process {
  var binaryPath: String? {
@@ -48,3 +52,4 @@ extension Process {
  }
  }
 }
+#endif

Sources/MultiNodeTestKitRunner/Terminal+Rainbow.swift

@@ -21,7 +21,6 @@ import OrderedCollections
 
 import struct Foundation.Date
 import class Foundation.FileHandle
-import class Foundation.Process
 import struct Foundation.URL
 
 enum Rainbow: String {

Sources/MultiNodeTestKitRunner/boot+MultiNodeTestKitRunner+Test.swift

@@ -20,11 +20,13 @@ import NIOPosix
 import OrderedCollections
 
 import struct Foundation.Date
-import class Foundation.FileHandle
-import class Foundation.Process
 import class Foundation.ProcessInfo
 import struct Foundation.URL
 
+#if canImport(Foundation.Process)
+import class Foundation.Process
+#endif
+
 // ==== ----------------------------------------------------------------------------------------------------------------
 // MARK: Code executing on each specific process/node
 
@@ -115,6 +117,10 @@ extension MultiNodeTestKitRunnerBoot {
  }
 
  func runMultiNodeTest(suite: String, testName: String, binary: String) async throws -> InterpretedRunResult {
+ #if !canImport(Foundation.Process)
+ struct UnsupportedPlatform: Error {}
+ throw UnsupportedPlatform()
+ #else
  let elg = MultiThreadedEventLoopGroup(numberOfThreads: 1)
  defer {
  try! elg.syncShutdownGracefully()
@@ -218,8 +224,10 @@ extension MultiNodeTestKitRunnerBoot {
 
  // all nodes passed okey
  return .passedAsExpected
+ #endif
  }
 
+ #if canImport(Foundation.Process)
  private func startTestTimeoutReaperTask(nodeName: String, process: Process, settings: MultiNodeTestSettings) -> Task<Void, Never> {
  Task.detached {
  try? await Task.sleep(until: .now + settings.execRunHardTimeout, clock: .continuous)
@@ -235,6 +243,7 @@ extension MultiNodeTestKitRunnerBoot {
  process.terminate()
  }
  }
+ #endif
 }
 
 struct NodeInterpretedRunResult {

Sources/MultiNodeTestKitRunner/boot+MultiNodeTestKitRunner.swift

@@ -21,13 +21,21 @@ import OrderedCollections
 
 import struct Foundation.Date
 import class Foundation.FileHandle
-import class Foundation.Process
 import struct Foundation.URL
 
+#if canImport(Foundation.Process)
+import class Foundation.Process
+#endif
+
 @main
 struct MultiNodeTestKitRunnerBoot {
  static func main() async throws {
+ #if !canImport(Foundation.Process)
+ print("Platform does not support multi-node tests")
+ throw ExitCode.failure
+ #else
  try await Self().run()
+ #endif
  }
 
  struct TestFilter {