Fix "escaped newline symbol" bug

Author: RoBo-Inc

CodeGeneration/Sources/SyntaxSupport/Utils.swift

@@ -42,35 +42,19 @@ public func lowercaseFirstWord(name: String) -> String {
 extension SwiftSyntax.Trivia {
   /// Make a new trivia from a (possibly multi-line) string, prepending `///`
   /// to each line and creating a `.docLineComment` trivia piece for each line.
-  public static func docCommentTrivia(from string: String?) -> SwiftSyntax.Trivia {
-    guard let string else {
-      return []
-    }
-
-    let lines = string.split(separator: "\n", omittingEmptySubsequences: false)
-    let pieces = lines.enumerated().map { (index, line) in
-      var line = line
-      if index != lines.count - 1 {
-        line = "\(line)\n"
-      }
-      return SwiftSyntax.TriviaPiece.docLineComment("/// \(line)")
-    }
-    return SwiftSyntax.Trivia(pieces: pieces)
+  public static func docCommentTrivia(from string: String?) -> Self {
+    guard let string else { return [] }
+    let lines = string.split(separator: "\n", omittingEmptySubsequences: false).map { "/// \($0)" }
+    return .init(pieces: lines.flatMap { [.docLineComment($0), .newlines(1)] })
   }
 
   /// Make a new trivia by joining together ``SwiftSyntax/TriviaPiece``s from `joining`,
   /// and gluing them together with pieces from `separator`.
   public init(
     joining items: [SwiftSyntax.Trivia],
-    separator: SwiftSyntax.Trivia = SwiftSyntax.Trivia(pieces: [TriviaPiece.newlines(1), TriviaPiece.docLineComment("///"), TriviaPiece.newlines(1)])
+    separator: SwiftSyntax.Trivia = .init(pieces: [.docLineComment("///"), .newlines(1)])
   ) {
-
-    self.init(
-      pieces:
-        items
-        .filter { !$0.isEmpty }
-        .joined(separator: separator)
-    )
+    self.init(pieces: items.filter { !$0.isEmpty }.joined(separator: separator))
   }
 }
 

CodeGeneration/Sources/generate-swift-syntax/templates/swiftsyntax/SyntaxBaseNodesFile.swift

@@ -173,7 +173,7 @@ let syntaxBaseNodesFile = SourceFileSyntax(leadingTrivia: copyrightHeader) {
 
     try! StructDeclSyntax(
       """
-      \(documentation)
+      \(documentation)\
       \(node.apiAttributes())\
       public struct \(node.kind.syntaxType): \(node.kind.protocolType), SyntaxHashable
       """

CodeGeneration/Sources/generate-swift-syntax/templates/swiftsyntax/SyntaxCollectionsFile.swift

@@ -26,7 +26,7 @@ let syntaxCollectionsFile = SourceFileSyntax(leadingTrivia: copyrightHeader) {
 
     try! StructDeclSyntax(
       """
-      \(documentation)
+      \(documentation)\
       \(node.node.apiAttributes())\
       public struct \(node.kind.syntaxType): SyntaxCollection, SyntaxHashable
       """

CodeGeneration/Sources/generate-swift-syntax/templates/swiftsyntax/SyntaxNodesFile.swift

@@ -27,7 +27,7 @@ func syntaxNode(nodesStartingWith: [Character]) -> SourceFileSyntax {
         """
         // MARK: - \(node.kind.syntaxType)
 
-        \(SwiftSyntax.Trivia(joining: [node.documentation, node.experimentalDocNote, node.grammar, node.containedIn]))
+        \(SwiftSyntax.Trivia(joining: [node.documentation, node.experimentalDocNote, node.grammar, node.containedIn]))\
         \(node.node.apiAttributes())\
         public struct \(node.kind.syntaxType): \(node.baseType.syntaxBaseName)Protocol, SyntaxHashable, \(node.base.leafProtocolType)
         """
@@ -55,7 +55,7 @@ func syntaxNode(nodesStartingWith: [Character]) -> SourceFileSyntax {
 
         try! InitializerDeclSyntax(
           """
-          \(node.generateInitializerDocComment())
+          \(node.generateInitializerDocComment())\
           \(node.generateInitializerDeclHeader())
           """
         ) {
@@ -137,7 +137,7 @@ func syntaxNode(nodesStartingWith: [Character]) -> SourceFileSyntax {
 
           try! VariableDeclSyntax(
             """
-            \(child.documentation)
+            \(child.documentation)\
             \(child.apiAttributes)public var \(child.varOrCaseName.backtickedIfNeeded): \(type)
             """
           ) {

CodeGeneration/Sources/generate-swift-syntax/templates/swiftsyntax/SyntaxTraitsFile.swift

@@ -21,11 +21,9 @@ let syntaxTraitsFile = SourceFileSyntax(leadingTrivia: copyrightHeader) {
       """
       // MARK: - \(trait.protocolName)
 
-      \(trait.documentation)
+      \(trait.documentation)\
       public protocol \(trait.protocolName): SyntaxProtocol\(raw:
-        trait.baseKind != nil
-          ? ", \(trait.baseKind!.protocolType)"
-          : ""
+        trait.baseKind == nil ? "" : ", \(trait.baseKind!.protocolType)"
       )
       """
     ) {
@@ -34,7 +32,7 @@ let syntaxTraitsFile = SourceFileSyntax(leadingTrivia: copyrightHeader) {
 
         DeclSyntax(
           """
-          \(child.documentation)
+          \(child.documentation)\
           \(child.apiAttributes)var \(child.varOrCaseName): \(child.syntaxNodeKind.syntaxType)\(raw: questionMark) { get set }
           """
         )

CodeGeneration/Sources/generate-swift-syntax/templates/swiftsyntaxbuilder/ResultBuildersFile.swift

@@ -23,7 +23,6 @@ let resultBuildersFile = SourceFileSyntax(leadingTrivia: copyrightHeader) {
 
     try! StructDeclSyntax(
       """
-
       // MARK: - \(type.resultBuilderType)
 
       @resultBuilder

Sources/SwiftSyntax/generated/SyntaxTraits.swift

@@ -14,7 +14,6 @@
 
 // MARK: - BracedSyntax
 
-
 public protocol BracedSyntax: SyntaxProtocol {
   /// ### Tokens
   /// 
@@ -62,7 +61,6 @@ public extension SyntaxProtocol {
 
 // MARK: - DeclGroupSyntax
 
-
 public protocol DeclGroupSyntax: SyntaxProtocol, DeclSyntaxProtocol {
   var attributes: AttributeListSyntax {
     get
@@ -120,7 +118,6 @@ public extension SyntaxProtocol {
 
 // MARK: - EffectSpecifiersSyntax
 
-
 public protocol EffectSpecifiersSyntax: SyntaxProtocol {
   var unexpectedBeforeAsyncSpecifier: UnexpectedNodesSyntax? {
     get
@@ -182,7 +179,6 @@ public extension SyntaxProtocol {
 
 // MARK: - FreestandingMacroExpansionSyntax
 
-
 public protocol FreestandingMacroExpansionSyntax: SyntaxProtocol {
   /// ### Tokens
   /// 
@@ -266,7 +262,6 @@ public extension SyntaxProtocol {
 
 // MARK: - NamedDeclSyntax
 
-
 public protocol NamedDeclSyntax: SyntaxProtocol {
   /// ### Tokens
   /// 
@@ -350,7 +345,6 @@ public extension SyntaxProtocol {
 
 // MARK: - ParenthesizedSyntax
 
-
 public protocol ParenthesizedSyntax: SyntaxProtocol {
   /// ### Tokens
   /// 
@@ -398,7 +392,6 @@ public extension SyntaxProtocol {
 
 // MARK: - WithAttributesSyntax
 
-
 public protocol WithAttributesSyntax: SyntaxProtocol {
   var attributes: AttributeListSyntax {
     get
@@ -435,7 +428,6 @@ public extension SyntaxProtocol {
 
 // MARK: - WithCodeBlockSyntax
 
-
 public protocol WithCodeBlockSyntax: SyntaxProtocol {
   var body: CodeBlockSyntax {
     get
@@ -518,7 +510,6 @@ public extension SyntaxProtocol {
 
 // MARK: - WithModifiersSyntax
 
-
 public protocol WithModifiersSyntax: SyntaxProtocol {
   var modifiers: DeclModifierListSyntax {
     get
@@ -555,7 +546,6 @@ public extension SyntaxProtocol {
 
 // MARK: - WithOptionalCodeBlockSyntax
 
-
 public protocol WithOptionalCodeBlockSyntax: SyntaxProtocol {
   var body: CodeBlockSyntax? {
     get
@@ -592,7 +582,6 @@ public extension SyntaxProtocol {
 
 // MARK: - WithStatementsSyntax
 
-
 public protocol WithStatementsSyntax: SyntaxProtocol {
   var statements: CodeBlockItemListSyntax {
     get
@@ -629,7 +618,6 @@ public extension SyntaxProtocol {
 
 // MARK: - WithTrailingCommaSyntax
 
-
 public protocol WithTrailingCommaSyntax: SyntaxProtocol {
   /// ### Tokens
   ///