Add edits to FixIt for sourcekit-lsp to access

Release Notes/511.md

@@ -1,6 +1,15 @@
 # Swift Syntax 511 Release Notes
 
 ## New APIs
+- FixIt now has a new computed propery named edits
+  - Description: the edits represent the non-overlapping textual edits that need to be performed when the Fix-It is applied.
+  - Issue: https://github.com/apple/sourcekit-lsp/issues/909
+  - Pull Request: https://github.com/apple/swift-syntax/pull/2314
+
+- SourceEdit
+  - Description: SourceEdit has been moved from SwiftRefactor to SwiftSyntax
+  - Issue: https://github.com/apple/sourcekit-lsp/issues/909
+  - Pull Request: https://github.com/apple/swift-syntax/pull/2314
 
 ## API Behavior Changes
 

Sources/SwiftDiagnostics/FixIt.swift

@@ -46,3 +46,45 @@ public struct FixIt {
     self.changes = changes
   }
 }
+
+extension FixIt {
+  /// The edits represent the non-overlapping textual edits that need to be performed when the Fix-It is applied.
+  public var edits: [SourceEdit] {
+    var existingEdits = [SourceEdit]()
+    for change in changes {
+      let edit = change.edit
+      let isOverlapping = existingEdits.contains { edit.range.overlaps($0.range) }
+      if !isOverlapping {
+        // The edit overlaps with the previous edit. We can't apply both
+        // without conflicts. Apply the one that's listed first and drop the
+        // later edit.
+        existingEdits.append(edit)
+      }
+    }
+    return existingEdits
+  }
+}
+
+private extension FixIt.Change {
+  var edit: SourceEdit {
+    switch self {
+    case .replace(let oldNode, let newNode):
+      return SourceEdit(
+        range: oldNode.position..<oldNode.endPosition,
+        replacement: newNode.description
+      )
+
+    case .replaceLeadingTrivia(let token, let newTrivia):
+      return SourceEdit(
+        range: token.position..<token.positionAfterSkippingLeadingTrivia,
+        replacement: newTrivia.description
+      )
+
+    case .replaceTrailingTrivia(let token, let newTrivia):
+      return SourceEdit(
+        range: token.endPositionBeforeTrailingTrivia..<token.endPosition,
+        replacement: newTrivia.description
+      )
+    }
+  }
+}

Sources/SwiftRefactor/RefactoringProvider.swift

@@ -109,64 +109,3 @@ extension SyntaxRefactoringProvider {
     return [SourceEdit.replace(syntax, with: output.description)]
   }
 }
-
-/// A textual edit to the original source represented by a range and a
-/// replacement.
-public struct SourceEdit: Equatable {
-  /// The half-open range that this edit applies to.
-  public let range: Range<AbsolutePosition>
-  /// The text to replace the original range with. Empty for a deletion.
-  public let replacement: String
-
-  /// Length of the original source range that this edit applies to. Zero if
-  /// this is an addition.
-  public var length: SourceLength {
-    return SourceLength(utf8Length: range.lowerBound.utf8Offset - range.upperBound.utf8Offset)
-  }
-
-  /// Create an edit to replace `range` in the original source with
-  /// `replacement`.
-  public init(range: Range<AbsolutePosition>, replacement: String) {
-    self.range = range
-    self.replacement = replacement
-  }
-
-  /// Convenience function to create a textual addition after the given node
-  /// and its trivia.
-  public static func insert(_ newText: String, after node: some SyntaxProtocol) -> SourceEdit {
-    return SourceEdit(range: node.endPosition..<node.endPosition, replacement: newText)
-  }
-
-  /// Convenience function to create a textual addition before the given node
-  /// and its trivia.
-  public static func insert(_ newText: String, before node: some SyntaxProtocol) -> SourceEdit {
-    return SourceEdit(range: node.position..<node.position, replacement: newText)
-  }
-
-  /// Convenience function to create a textual replacement of the given node,
-  /// including its trivia.
-  public static func replace(_ node: some SyntaxProtocol, with replacement: String) -> SourceEdit {
-    return SourceEdit(range: node.position..<node.endPosition, replacement: replacement)
-  }
-
-  /// Convenience function to create a textual deletion the given node and its
-  /// trivia.
-  public static func remove(_ node: some SyntaxProtocol) -> SourceEdit {
-    return SourceEdit(range: node.position..<node.endPosition, replacement: "")
-  }
-}
-
-extension SourceEdit: CustomDebugStringConvertible {
-  public var debugDescription: String {
-    let hasNewline = replacement.contains { $0.isNewline }
-    if hasNewline {
-      return #"""
-        \#(range.lowerBound.utf8Offset)-\#(range.upperBound.utf8Offset)
-        """
-        \#(replacement)
-        """
-        """#
-    }
-    return "\(range.lowerBound.utf8Offset)-\(range.upperBound.utf8Offset) \"\(replacement)\""
-  }
-}

Sources/SwiftSyntax/CMakeLists.txt

@@ -16,6 +16,7 @@ add_swift_syntax_library(SwiftSyntax
   Convenience.swift
   MemoryLayout.swift
   MissingNodeInitializers.swift
+  SourceEdit.swift
   SourceLength.swift
   SourceLocation.swift
   SourcePresence.swift

Sources/SwiftSyntax/SourceEdit.swift

@@ -0,0 +1,72 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2023 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
+//
+//===----------------------------------------------------------------------===//
+
+/// A textual edit to the original source represented by a range and a
+/// replacement.
+public struct SourceEdit: Equatable {
+  /// The half-open range that this edit applies to.
+  public let range: Range<AbsolutePosition>
+  /// The text to replace the original range with. Empty for a deletion.
+  public let replacement: String
+
+  /// Length of the original source range that this edit applies to. Zero if
+  /// this is an addition.
+  public var length: SourceLength {
+    return SourceLength(utf8Length: range.lowerBound.utf8Offset - range.upperBound.utf8Offset)
+  }
+
+  /// Create an edit to replace `range` in the original source with
+  /// `replacement`.
+  public init(range: Range<AbsolutePosition>, replacement: String) {
+    self.range = range
+    self.replacement = replacement
+  }
+
+  /// Convenience function to create a textual addition after the given node
+  /// and its trivia.
+  public static func insert(_ newText: String, after node: some SyntaxProtocol) -> SourceEdit {
+    return SourceEdit(range: node.endPosition..<node.endPosition, replacement: newText)
+  }
+
+  /// Convenience function to create a textual addition before the given node
+  /// and its trivia.
+  public static func insert(_ newText: String, before node: some SyntaxProtocol) -> SourceEdit {
+    return SourceEdit(range: node.position..<node.position, replacement: newText)
+  }
+
+  /// Convenience function to create a textual replacement of the given node,
+  /// including its trivia.
+  public static func replace(_ node: some SyntaxProtocol, with replacement: String) -> SourceEdit {
+    return SourceEdit(range: node.position..<node.endPosition, replacement: replacement)
+  }
+
+  /// Convenience function to create a textual deletion the given node and its
+  /// trivia.
+  public static func remove(_ node: some SyntaxProtocol) -> SourceEdit {
+    return SourceEdit(range: node.position..<node.endPosition, replacement: "")
+  }
+}
+
+extension SourceEdit: CustomDebugStringConvertible {
+  public var debugDescription: String {
+    let hasNewline = replacement.contains { $0.isNewline }
+    if hasNewline {
+      return #"""
+        \#(range.lowerBound.utf8Offset)-\#(range.upperBound.utf8Offset)
+        """
+        \#(replacement)
+        """
+        """#
+    }
+    return "\(range.lowerBound.utf8Offset)-\(range.upperBound.utf8Offset) \"\(replacement)\""
+  }
+}

Sources/_SwiftSyntaxTestSupport/FixItApplier.swift

@@ -14,20 +14,6 @@ import SwiftDiagnostics
 import SwiftSyntax
 
 public enum FixItApplier {
-  struct Edit: Equatable {
-    var startUtf8Offset: Int
-    var endUtf8Offset: Int
-    let replacement: String
-
-    var replacementLength: Int {
-      return replacement.utf8.count
-    }
-
-    var replacementRange: Range<Int> {
-      return startUtf8Offset..<endUtf8Offset
-    }
-  }
-
   /// Applies selected or all Fix-Its from the provided diagnostics to a given syntax tree.
   ///
   /// - Parameters:
@@ -44,13 +30,12 @@ public enum FixItApplier {
   ) -> String {
     let messages = messages ?? diagnostics.compactMap { $0.fixIts.first?.message.message }
 
-    let changes =
+    var edits =
       diagnostics
       .flatMap(\.fixIts)
       .filter { messages.contains($0.message.message) }
-      .flatMap(\.changes)
+      .flatMap(\.edits)
 
-    var edits: [Edit] = changes.map(\.edit)
     var source = tree.description
 
     while let edit = edits.first {
@@ -61,9 +46,7 @@ public enum FixItApplier {
 
       source.replaceSubrange(startIndex..<endIndex, with: edit.replacement)
 
-      edits = edits.compactMap { remainingEdit -> FixItApplier.Edit? in
-        var remainingEdit = remainingEdit
-
+      edits = edits.compactMap { remainingEdit -> SourceEdit? in
         if remainingEdit.replacementRange.overlaps(edit.replacementRange) {
           // The edit overlaps with the previous edit. We can't apply both
           // without conflicts. Apply the one that's listed first and drop the
@@ -74,8 +57,9 @@ public enum FixItApplier {
         // If the remaining edit starts after or at the end of the edit that we just applied,
         // shift it by the current edit's difference in length.
         if edit.endUtf8Offset <= remainingEdit.startUtf8Offset {
-          remainingEdit.startUtf8Offset = remainingEdit.startUtf8Offset - edit.replacementRange.count + edit.replacementLength
-          remainingEdit.endUtf8Offset = remainingEdit.endUtf8Offset - edit.replacementRange.count + edit.replacementLength
+          let startPosition = AbsolutePosition(utf8Offset: remainingEdit.startUtf8Offset - edit.replacementRange.count + edit.replacementLength)
+          let endPosition = AbsolutePosition(utf8Offset: remainingEdit.endUtf8Offset - edit.replacementRange.count + edit.replacementLength)
+          return SourceEdit(range: startPosition..<endPosition, replacement: remainingEdit.replacement)
         }
 
         return remainingEdit
@@ -86,29 +70,20 @@ public enum FixItApplier {
   }
 }
 
-fileprivate extension FixIt.Change {
-  var edit: FixItApplier.Edit {
-    switch self {
-    case .replace(let oldNode, let newNode):
-      return FixItApplier.Edit(
-        startUtf8Offset: oldNode.position.utf8Offset,
-        endUtf8Offset: oldNode.endPosition.utf8Offset,
-        replacement: newNode.description
-      )
+private extension SourceEdit {
+  var startUtf8Offset: Int {
+    return range.lowerBound.utf8Offset
+  }
+
+  var endUtf8Offset: Int {
+    return range.upperBound.utf8Offset
+  }
 
-    case .replaceLeadingTrivia(let token, let newTrivia):
-      return FixItApplier.Edit(
-        startUtf8Offset: token.position.utf8Offset,
-        endUtf8Offset: token.positionAfterSkippingLeadingTrivia.utf8Offset,
-        replacement: newTrivia.description
-      )
+  var replacementLength: Int {
+    return replacement.utf8.count
+  }
 
-    case .replaceTrailingTrivia(let token, let newTrivia):
-      return FixItApplier.Edit(
-        startUtf8Offset: token.endPositionBeforeTrailingTrivia.utf8Offset,
-        endUtf8Offset: token.endPosition.utf8Offset,
-        replacement: newTrivia.description
-      )
-    }
+  var replacementRange: Range<Int> {
+    return startUtf8Offset..<endUtf8Offset
   }
 }

Tests/SwiftDiagnosticsTest/FixItTests.swift

@@ -0,0 +1,42 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2023 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 SwiftParser
+import SwiftParserDiagnostics
+import SwiftSyntax
+import XCTest
+import _SwiftSyntaxTestSupport
+
+final class FixItTests: XCTestCase {
+  func testEditsForFixIt() throws {
+    let markedSource = "protocol 1️⃣Multi 2️⃣ident 3️⃣{}"
+    let (markers, source) = extractMarkers(markedSource)
+    let positions = markers.mapValues { AbsolutePosition(utf8Offset: $0) }
+    XCTAssertEqual(positions.count, 3)
+
+    let expectedEdits = [
+      SourceEdit(range: positions["1️⃣"]!..<positions["2️⃣"]!, replacement: "Multiident "),
+      SourceEdit(range: positions["2️⃣"]!..<positions["3️⃣"]!, replacement: ""),
+    ]
+    let tree = Parser.parse(source: source)
+    let diags = ParseDiagnosticsGenerator.diagnostics(for: tree)
+    XCTAssertEqual(diags.count, 1)
+    let diag = try XCTUnwrap(diags.first)
+    XCTAssertEqual(diag.fixIts.count, 2)
+
+    let fixIt = try XCTUnwrap(diag.fixIts.first)
+    let changes = fixIt.changes
+    let edits = fixIt.edits
+    XCTAssertNotEqual(changes.count, edits.count)
+    XCTAssertEqual(expectedEdits, edits)
+  }
+}