Merge pull request #2760 from mattwar/Bug293

add base list before trailing trivia

src/Diagnostics/FxCop/System.Runtime.Analyzers/Test/Design/TypesThatOwnDisposableFieldsShouldBeDisposableTests.Fixer.cs

@@ -53,8 +53,7 @@ public NoDisposeClass()
 using System.IO;
 
 // This class violates the rule.
-public class NoDisposeClass
-: IDisposable
+public class NoDisposeClass : IDisposable
 {
     FileStream newFile;
 
@@ -132,8 +131,7 @@ public class NoDisposeClass
 using System.IO;
 
 // This class violates the rule.
-public class NoDisposeClass
-: IDisposable
+public class NoDisposeClass : IDisposable
 {
     FileStream newFile;
 
@@ -166,8 +164,7 @@ public partial class NoDisposeClass
 using System.IO;
 
 // This class violates the rule.
-public partial class NoDisposeClass
-: IDisposable
+public partial class NoDisposeClass : IDisposable
 {
     FileStream newFile;
 

src/Workspaces/CSharp/Portable/CodeGeneration/CSharpSyntaxGenerator.cs

@@ -2907,22 +2907,36 @@ public override SyntaxNode AddBaseType(SyntaxNode declaration, SyntaxNode baseTy
         {
             var baseList = this.GetBaseList(declaration);
 
-            var newBaseList = (baseList != null)
-                ? baseList.WithTypes(baseList.Types.Insert(0, SyntaxFactory.SimpleBaseType((TypeSyntax)baseType)))
-                : SyntaxFactory.BaseList(SyntaxFactory.SingletonSeparatedList<BaseTypeSyntax>(SyntaxFactory.SimpleBaseType((TypeSyntax)baseType)));
-
-            return this.WithBaseList(declaration, newBaseList);
+            if (baseList != null)
+            {
+                return this.WithBaseList(declaration, baseList.WithTypes(baseList.Types.Insert(0, SyntaxFactory.SimpleBaseType((TypeSyntax)baseType))));
+            }
+            else
+            {
+                return this.AddBaseList(declaration, SyntaxFactory.BaseList(SyntaxFactory.SingletonSeparatedList<BaseTypeSyntax>(SyntaxFactory.SimpleBaseType((TypeSyntax)baseType))));
+            }
         }
 
         public override SyntaxNode AddInterfaceType(SyntaxNode declaration, SyntaxNode interfaceType)
         {
             var baseList = this.GetBaseList(declaration);
 
-            var newBaseList = (baseList != null)
-                ? baseList.WithTypes(baseList.Types.Insert(baseList.Types.Count, SyntaxFactory.SimpleBaseType((TypeSyntax)interfaceType)))
-                : SyntaxFactory.BaseList(SyntaxFactory.SingletonSeparatedList<BaseTypeSyntax>(SyntaxFactory.SimpleBaseType((TypeSyntax)interfaceType)));
+            if (baseList != null)
+            {
+                return this.WithBaseList(declaration, baseList.WithTypes(baseList.Types.Insert(baseList.Types.Count, SyntaxFactory.SimpleBaseType((TypeSyntax)interfaceType))));
+            }
+            else
+            {
+                return this.AddBaseList(declaration, SyntaxFactory.BaseList(SyntaxFactory.SingletonSeparatedList<BaseTypeSyntax>(SyntaxFactory.SimpleBaseType((TypeSyntax)interfaceType))));
+            }
+        }
+
+        private SyntaxNode AddBaseList(SyntaxNode declaration, BaseListSyntax baseList)
+        {
+            var newDecl = this.WithBaseList(declaration, baseList);
 
-            return this.WithBaseList(declaration, newBaseList);
+            // move trivia from type identifier to after base list
+            return this.ShiftTrivia(newDecl, this.GetBaseList(newDecl));
         }
 
         private BaseListSyntax GetBaseList(SyntaxNode declaration)
@@ -3237,6 +3251,26 @@ private SyntaxNode RemoveNodeInternal(SyntaxNode root, SyntaxNode declaration)
 
             return base.RemoveNode(root, declaration);
         }
+
+        /// <summary>
+        /// Moves the trailing trivia from the node's previous token to the end of the node
+        /// </summary>
+        private SyntaxNode ShiftTrivia(SyntaxNode root, SyntaxNode node)
+        {
+            var firstToken = node.GetFirstToken();
+            var previousToken = firstToken.GetPreviousToken();
+            if (previousToken != default(SyntaxToken) && root.Contains(previousToken.Parent))
+            {
+                var newNode = node.WithTrailingTrivia(node.GetTrailingTrivia().AddRange(previousToken.TrailingTrivia));
+                var newPreviousToken = previousToken.WithTrailingTrivia(default(SyntaxTriviaList));
+                return root.ReplaceSyntax(
+                    nodes: new[] { node }, computeReplacementNode: (o, r) => newNode,
+                    tokens: new[] { previousToken }, computeReplacementToken: (o, r) => newPreviousToken,
+                    trivia: null, computeReplacementTrivia: null);
+            }
+
+            return root;
+        }
 #endregion
 
 #region Statements and Expressions

src/Workspaces/CSharpTest/CodeGeneration/SymbolEditorTests.cs

@@ -816,8 +816,7 @@ class A
 }";
 
             var expected =
-@"class C
-: A
+@"class C : A
 {
 }
 

src/Workspaces/CSharpTest/CodeGeneration/SyntaxGeneratorTests.cs

@@ -5,6 +5,7 @@
 using Microsoft.CodeAnalysis.CodeGeneration;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Editing;
+using Microsoft.CodeAnalysis.Formatting;
 using Microsoft.CodeAnalysis.Test.Utilities;
 using Microsoft.CodeAnalysis.Text;
 using Roslyn.Test.Utilities;
@@ -14,7 +15,8 @@ namespace Microsoft.CodeAnalysis.CSharp.UnitTests.Editting
 {
     public class SyntaxGeneratorTests
     {
-        private readonly SyntaxGenerator _g = SyntaxGenerator.GetGenerator(new AdhocWorkspace(), LanguageNames.CSharp);
+        private readonly Workspace _ws;
+        private readonly SyntaxGenerator _g;
 
         private readonly CSharpCompilation _emptyCompilation = CSharpCompilation.Create("empty",
                 references: new[] { TestReferences.NetFx.v4_0_30319.mscorlib, TestReferences.NetFx.v4_0_30319.System });
@@ -23,6 +25,8 @@ public class SyntaxGeneratorTests
 
         public SyntaxGeneratorTests()
         {
+            _ws = new AdhocWorkspace();
+            _g = SyntaxGenerator.GetGenerator(_ws, LanguageNames.CSharp);
             _ienumerableInt = _emptyCompilation.GetSpecialType(SpecialType.System_Collections_Generic_IEnumerable_T).Construct(_emptyCompilation.GetSpecialType(SpecialType.System_Int32));
         }
 
@@ -2867,6 +2871,32 @@ public void M()
 {
 }");
         }
-#endregion
+
+        [WorkItem(293, "https://github.com/dotnet/roslyn/issues/293")]
+        [Fact]
+        [Trait(Traits.Feature, Traits.Features.Formatting)]
+        public void IntroduceBaseList()
+        {
+            var text = @"
+public class C
+{
+}
+";
+            var expected = @"
+public class C : IDisposable
+{
+}
+";
+
+            var root = SyntaxFactory.ParseCompilationUnit(text);
+            var decl = root.DescendantNodes().OfType<ClassDeclarationSyntax>().First();
+            var newDecl = _g.AddInterfaceType(decl, _g.IdentifierName("IDisposable"));
+            var newRoot = root.ReplaceNode(decl, newDecl);
+
+            var elasticOnlyFormatted = Formatter.Format(newRoot, SyntaxAnnotation.ElasticAnnotation, _ws).ToFullString();
+            Assert.Equal(expected, elasticOnlyFormatted);
+        }
+
+        #endregion
     }
 }