Add method on Process that waits until exit and sends a SIGINT to the process if the Task is cancelled

Author: ahoppen

Sources/SKSupport/CMakeLists.txt

@@ -11,6 +11,7 @@ add_library(SKSupport STATIC
   DocumentURI+CustomLogStringConvertible.swift
   FileSystem.swift
   LineTable.swift
+  Process+WaitUntilExitWithCancellation.swift
   Random.swift
   Result.swift
   ThreadSafeBox.swift

Sources/SKSupport/Process+WaitUntilExitWithCancellation.swift

@@ -0,0 +1,27 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import Foundation
+
+import class TSCBasic.Process
+import struct TSCBasic.ProcessResult
+
+public extension Process {
+  /// Wait for the process to exit. If the task gets cancelled, during this time, send a `SIGINT` to the process.
+  func waitUntilExitSendingSigIntOnTaskCancellation() async throws -> ProcessResult {
+    return try await withTaskCancellationHandler {
+      try await waitUntilExit()
+    } onCancel: {
+      signal(SIGINT)
+    }
+  }
+}

Sources/SourceKitLSP/Swift/DocumentFormatting.swift

@@ -154,7 +154,7 @@ extension SwiftLanguageService {
     writeStream.send(snapshot.text)
     try writeStream.close()
 
-    let result = try await process.waitUntilExit()
+    let result = try await process.waitUntilExitSendingSigIntOnTaskCancellation()
     guard result.exitStatus == .terminated(code: 0) else {
       let swiftFormatErrorMessage: String
       switch result.stderrOutput {