Consistently apply .tgz to the preferred name of a compressed directory

Author: grynspan

Sources/Overlays/_Testing_Foundation/Attachments/Test.Attachment+URL.swift

@@ -12,6 +12,10 @@
 @_spi(Experimental) public import Testing
 public import Foundation
 
+#if SWT_TARGET_OS_APPLE && canImport(UniformTypeIdentifiers)
+private import UniformTypeIdentifiers
+#endif
+
 #if !SWT_NO_FILE_IO
 extension URL {
   /// The file system path of the URL, equivalent to `path`.
@@ -30,6 +34,15 @@ extension URL {
 
 // MARK: - Attaching files
 
+#if SWT_TARGET_OS_APPLE && canImport(UniformTypeIdentifiers)
+@available(_uttypesAPI, *)
+extension UTType {
+  /// A type that represents a `.tgz` archive, or `nil` if the system does not
+  /// recognize that content type.
+  fileprivate static let tgz = UTType("org.gnu.gnu-zip-tar-archive")
+}
+#endif
+
 @_spi(Experimental)
 extension Test.Attachment {
   /// Initialize an instance of this type with the contents of the given URL.
@@ -57,25 +70,33 @@ extension Test.Attachment {
     let url = url.resolvingSymlinksInPath()
     let isDirectory = try url.resourceValues(forKeys: [.isDirectoryKey]).isDirectory!
 
-    let attachableValue: any Test.Attachable & Sendable
-    if isDirectory {
-      attachableValue = try await _DirectoryContentAttachableProxy(contentsOfDirectoryAt: url)
+    // Determine the preferred name of the attachment if one was not provided.
+    var preferredName = if let preferredName {
+      preferredName
+    } else if case let lastPathComponent = url.lastPathComponent, !lastPathComponent.isEmpty {
+      lastPathComponent
     } else {
-      // Load the file.
-      attachableValue = try Data(contentsOf: url, options: [.mappedIfSafe])
+      Self.defaultPreferredName
     }
 
-    // Determine the preferred name of the attachment if one was not provided.
-    var preferredName = preferredName
-    if preferredName == nil, case let lastPathComponent = url.lastPathComponent, !lastPathComponent.isEmpty {
-      if isDirectory {
-        preferredName = (lastPathComponent as NSString).appendingPathExtension("tar.gz")
-      } else {
-        preferredName = lastPathComponent
-      }
-    }
+    if isDirectory {
+      // Ensure the preferred name of the archive has an appropriate extension.
+      preferredName = {
+#if SWT_TARGET_OS_APPLE && canImport(UniformTypeIdentifiers)
+        if #available(_uttypesAPI, *), let tgz = UTType.tgz {
+          return (preferredName as NSString).appendingPathExtension(for: tgz)
+        }
+#endif
+        return (preferredName as NSString).appendingPathExtension("tgz") ?? preferredName
+      }()
 
-    self.init(attachableValue, named: preferredName, sourceLocation: sourceLocation)
+      let attachableValue = try await _DirectoryContentAttachableProxy(contentsOfDirectoryAt: url)
+      self.init(attachableValue, named: preferredName, sourceLocation: sourceLocation)
+    } else {
+      // Load the file.
+      let attachableValue = try Data(contentsOf: url, options: [.mappedIfSafe])
+      self.init(attachableValue, named: preferredName, sourceLocation: sourceLocation)
+    }
   }
 }
 
@@ -101,12 +122,12 @@ private struct _DirectoryContentAttachableProxy: Test.Attachable {
   ///   directories cannot be compressed on this platform.
   ///
   /// This initializer asynchronously compresses the contents of `directoryURL`
-  /// into an archive (currently of `.tar.gz` format, although this is subject
-  /// to change) and stores a mapped copy of that archive.
+  /// into an archive (currently of `.tgz` format, although this is subject to
+  /// change) and stores a mapped copy of that archive.
   init(contentsOfDirectoryAt directoryURL: URL) async throws {
     url = directoryURL
 
-    let temporaryName = "\(UUID().uuidString).tar.gz"
+    let temporaryName = "\(UUID().uuidString).tgz"
     let temporaryURL = FileManager.default.temporaryDirectory.appendingPathComponent(temporaryName)
 
 #if !SWT_NO_PROCESS_SPAWNING

Tests/TestingTests/AttachmentTests.swift

@@ -82,7 +82,7 @@ struct AttachmentTests {
 
   @Test func writeAttachmentWithMultiplePathExtensions() throws {
     let attachableValue = MySendableAttachable(string: "<!doctype html>")
-    let attachment = Test.Attachment(attachableValue, named: "loremipsum.tar.gz.gif.jpeg.html")
+    let attachment = Test.Attachment(attachableValue, named: "loremipsum.tgz.gif.jpeg.html")
 
     // Write the attachment to disk once to ensure the original filename is not
     // available and we add a suffix.
@@ -98,7 +98,7 @@ struct AttachmentTests {
       remove(filePath)
     }
     let fileName = try #require(filePath.split { $0 == "/" || $0 == #"\"# }.last)
-    #expect(fileName == "loremipsum-\(suffix).tar.gz.gif.jpeg.html")
+    #expect(fileName == "loremipsum-\(suffix).tgz.gif.jpeg.html")
     try compare(attachableValue, toContentsOfFileAtPath: filePath)
   }
 
@@ -270,7 +270,7 @@ struct AttachmentTests {
           return
         }
 
-        #expect(attachment.preferredName == "\(temporaryDirectoryName).tar.gz")
+        #expect(attachment.preferredName == "\(temporaryDirectoryName).tgz")
         valueAttached()
       }