Issue dev_compiler@443. Clone beginToken.

pkg/analyzer/lib/src/dart/ast/utilities.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer.src.dart.ast.utilities;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
@@ skipping 198 matching lines @@
         cloneNodeList(node.members),
         cloneToken(node.rightBracket));
     copy.nativeClause = cloneNode(node.nativeClause);
     return copy;
   }
 
   @override
   ClassTypeAlias visitClassTypeAlias(ClassTypeAlias node) {
     cloneToken(node.abstractKeyword);
     return new ClassTypeAlias(
-      cloneNode(node.documentationComment),
-      cloneNodeList(node.metadata),
-      cloneToken(node.typedefKeyword),
-      cloneNode(node.name),
-      cloneNode(node.typeParameters),
-      cloneToken(node.equals),
-      cloneToken(node.abstractKeyword),
-      cloneNode(node.superclass),
-      cloneNode(node.withClause),
-      cloneNode(node.implementsClause),
-      cloneToken(node.semicolon));
+        cloneNode(node.documentationComment),
+        cloneNodeList(node.metadata),
+        cloneToken(node.typedefKeyword),
+        cloneNode(node.name),
+        cloneNode(node.typeParameters),
+        cloneToken(node.equals),
+        cloneToken(node.abstractKeyword),
+        cloneNode(node.superclass),
+        cloneNode(node.withClause),
+        cloneNode(node.implementsClause),
+        cloneToken(node.semicolon));
   }
 
   @override
   Comment visitComment(Comment node) {
     if (node.isDocumentation) {
       return Comment.createDocumentationCommentWithReferences(
           cloneTokenList(node.tokens), cloneNodeList(node.references));
     } else if (node.isBlock) {
       return Comment.createBlockComment(cloneTokenList(node.tokens));
     }
     return Comment.createEndOfLineComment(cloneTokenList(node.tokens));
   }
 
   @override
   CommentReference visitCommentReference(CommentReference node) =>
       new CommentReference(
           cloneToken(node.newKeyword), cloneNode(node.identifier));
 
   @override
   CompilationUnit visitCompilationUnit(CompilationUnit node) {
-    ScriptTag scriptTag = cloneNode(node.scriptTag);
-    List<Directive> directives = cloneNodeList(node.directives);
-    List<CompilationUnitMember> declarations = cloneNodeList(node.declarations);
-    Token endToken = cloneToken(node.endToken);
-    Token beginToken = scriptTag?.beginToken ??
-        (directives.isEmpty ? null : directives.first.beginToken) ??
-        (declarations.isEmpty ? null : declarations.first.beginToken) ??
-        endToken;
     CompilationUnit clone = new CompilationUnit(
-        beginToken, scriptTag, directives, declarations, endToken);
+        cloneToken(node.beginToken),
+        cloneNode(node.scriptTag),
+        cloneNodeList(node.directives),
+        cloneNodeList(node.declarations),
+        cloneToken(node.endToken));
     clone.lineInfo = node.lineInfo;
     return clone;
   }
 
   @override
   ConditionalExpression visitConditionalExpression(
           ConditionalExpression node) =>
       new ConditionalExpression(
           cloneNode(node.condition),
           cloneToken(node.question),
@@ skipping 6076 matching lines @@
    * Safely visit the given [token], printing the [suffix] after the token if it
    * is non-`null`.
    */
   void _visitTokenWithSuffix(Token token, String suffix) {
     if (token != null) {
       _writer.print(token.lexeme);
       _writer.print(suffix);
     }
   }
 }