Merge main into release/6.1

Sources/SwiftFormat/PrettyPrint/Comment.swift

@@ -67,9 +67,9 @@ struct Comment {
 
     switch kind {
     case .line, .docLine:
+      self.length = text.count
       self.text = [text]
       self.text[0].removeFirst(kind.prefixLength)
-      self.length = self.text.reduce(0, { $0 + $1.count + kind.prefixLength + 1 })
 
     case .block, .docBlock:
       var fulltext: String = text

Sources/SwiftFormat/Utilities/URL+isRoot.swift

@@ -12,21 +12,44 @@
 
 import Foundation
 
+#if os(Windows)
+import WinSDK
+#endif
+
 extension URL {
+  /// Returns a `Bool` to indicate if the given `URL` leads to the root of a filesystem.
+  /// A non-filesystem type `URL` will always return false.
   @_spi(Testing) public var isRoot: Bool {
+    guard isFileURL else { return false }
+
+    #if compiler(>=6.1)
+    #if os(Windows)
+    let filePath = self.withUnsafeFileSystemRepresentation { pointer in
+      guard let pointer else {
+        return ""
+      }
+      return String(cString: pointer)
+    }
+    return filePath.withCString(encodedAs: UTF16.self, PathCchIsRoot)
+    #else  // os(Windows)
+    return self.path == "/"
+    #endif  // os(Windows)
+    #else  // compiler(>=6.1)
+
     #if os(Windows)
-    // FIXME: We should call into Windows' native check to check if this path is a root once https://github.com/swiftlang/swift-foundation/issues/976 is fixed.
+    // This is needed as the fixes from #844 aren't in the Swift 6.0 toolchain.
     // https://github.com/swiftlang/swift-format/issues/844
     var pathComponents = self.pathComponents
     if pathComponents.first == "/" {
       // Canonicalize `/C:/` to `C:/`.
       pathComponents = Array(pathComponents.dropFirst())
     }
     return pathComponents.count <= 1
-    #else
+    #else  // os(Windows)
     // On Linux, we may end up with an string for the path due to https://github.com/swiftlang/swift-foundation/issues/980
-    // TODO: Remove the check for "" once https://github.com/swiftlang/swift-foundation/issues/980 is fixed.
+    // This is needed as the fixes from #980 aren't in the Swift 6.0 toolchain.
     return self.path == "/" || self.path == ""
-    #endif
+    #endif  // os(Windows)
+    #endif  // compiler(>=6.1)
   }
 }

Tests/SwiftFormatTests/PrettyPrint/CommentTests.swift

@@ -1009,6 +1009,29 @@ final class CommentTests: PrettyPrintTestCase {
     )
   }
 
+  // Tests that "end of line" comments are flagged only when they exceed the configured line length.
+  func testDiagnoseMoveEndOfLineCommentAroundBoundary() {
+    assertPrettyPrintEqual(
+      input: """
+        x  // 789
+        x  // 7890
+        x  1️⃣// 78901
+
+        """,
+      expected: """
+        x  // 789
+        x  // 7890
+        x  // 78901
+
+        """,
+      linelength: 10,
+      whitespaceOnly: true,
+      findings: [
+        FindingSpec("1️⃣", message: "move end-of-line comment that exceeds the line length")
+      ]
+    )
+  }
+
   func testLineWithDocLineComment() {
     // none of these should be merged if/when there is comment formatting
     let input =

Tests/SwiftFormatTests/Utilities/FileIteratorTests.swift

@@ -103,12 +103,14 @@ final class FileIteratorTests: XCTestCase {
     while !root.isRoot {
       root.deleteLastPathComponent()
     }
-    var rootPath = root.path
     #if os(Windows) && compiler(<6.1)
+    var rootPath = root.path
     if rootPath.hasPrefix("/") {
       // Canonicalize /C: to C:
       rootPath = String(rootPath.dropFirst())
     }
+    #else
+    let rootPath = root.path
     #endif
     // Make sure that we don't drop the beginning of the path if we are running in root.
     // https://github.com/swiftlang/swift-format/issues/862