Merge pull request #5371 from balajikris/GMWinForms-144843

Prefer normal files over auto generated files for code generation destinations

src/EditorFeatures/Test2/Diagnostics/GenerateEvent/GenerateEventCrossLanguageTests.vb

@@ -115,5 +115,49 @@ public delegate void EvHandler(int x);
 
             Test(input, expected)
         End Sub
+
+        <WorkItem(144843, "Generate method stub generates into *.Designer.cs")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsGenerateEvent)>
+        Public Sub PreferNormalFileOverAutoGeneratedFile_Basic()
+            Dim input =
+        <Workspace>
+            <Project Language="Visual Basic" AssemblyName="VBAssembly1" CommonReferences="true">
+                <Document>
+Class c
+    WithEvents field as UserControl1
+    Sub Foo(x as Integer) Handles field.Ev$$
+    End Sub
+End Class
+                </Document>
+                <Document FilePath="UserControl1.Designer.vb">
+' This file is auto-generated
+Partial Class UserControl1
+End Class
+                </Document>
+                <Document FilePath="UserControl1.vb">
+Partial Public Class UserControl1
+End Class
+                </Document>
+            </Project>
+        </Workspace>
+
+            Dim expectedFileWithText =
+                 New Dictionary(Of String, String) From {
+                    {"UserControl1.vb",
+<Text>
+Partial Public Class UserControl1
+    Public Event Ev(x As Integer)
+End Class
+</Text>.Value.Trim()},
+                    {"UserControl1.Designer.vb",
+<Text>
+' This file is auto-generated
+Partial Class UserControl1
+End Class
+</Text>.Value.Trim()}
+                }
+
+            Test(input, fileNameToExpected:=expectedFileWithText)
+        End Sub
     End Class
 End Namespace

src/EditorFeatures/Test2/Diagnostics/GenerateFromUsage/GenerateMethodCrossLanguageTests.vb

@@ -1071,5 +1071,276 @@ End Module]]>
 
             Test(input, expected)
         End Sub
+
+#Region "Normal tests"
+
+        <WorkItem(144843, "Generate method stub generates into *.Designer.cs")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsGenerateMethod)>
+        Public Sub PreferNormalFileOverAutoGeneratedFile_CSharp()
+            Dim input =
+<Workspace>
+    <Project Language="C#" CommonReferences="true">
+        <Document FilePath="Form1.cs">
+class Form1
+{
+    void M() 
+    { 
+        UserControl1 control;
+        control.Draw$$();
+    }
+}
+        </Document>
+        <Document FilePath="UserControl1.Designer.cs">
+// This file is auto-generated
+partial class UserControl1
+{
+    
+}
+        </Document>
+        <Document FilePath="UserControl1.cs">
+public partial class UserControl1
+{
+    
+}
+        </Document>
+    </Project>
+</Workspace>
+
+            Dim expectedFileWithText =
+                 New Dictionary(Of String, String) From {
+                    {"UserControl1.cs",
+<Text>
+using System;
+public partial class UserControl1
+{
+    internal void Draw()
+    {
+        throw new NotImplementedException();
+    }
+}
+</Text>.Value.Trim()},
+                    {"UserControl1.Designer.cs",
+<Text>
+// This file is auto-generated
+partial class UserControl1
+{
+    
+}
+</Text>.Value.Trim()}
+                }
+
+            Test(input, fileNameToExpected:=expectedFileWithText)
+        End Sub
+
+        <WorkItem(144843, "Generate method stub generates into *.Designer.cs")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsGenerateMethod)>
+        Public Sub IntoAutoGeneratedFileIfNoBetterLocationExists_CSharp()
+            Dim input =
+<Workspace>
+    <Project Language="C#" CommonReferences="true">
+        <Document FilePath="Form1.cs">
+class Form1
+{
+    void M() 
+    { 
+        UserControl1 control;
+        control.Draw$$();
+    }
+}
+        </Document>
+        <Document FilePath="UserControl1.Designer.cs">
+// This file is auto-generated
+partial class UserControl1
+{
+    
+}
+        </Document>
+    </Project>
+</Workspace>
+
+            Dim expectedFileWithText =
+                 New Dictionary(Of String, String) From {
+                    {"UserControl1.Designer.cs",
+<Text>
+using System;
+// This file is auto-generated
+partial class UserControl1
+{
+    internal void Draw()
+    {
+        throw new NotImplementedException();
+    }
+}
+</Text>.Value.Trim()}}
+
+            Test(input, fileNameToExpected:=expectedFileWithText)
+        End Sub
+
+        <WorkItem(144843, "Generate method stub generates into *.Designer.cs")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsGenerateMethod)>
+        Public Sub InAutoGeneratedFiles_CSharp()
+            Dim input =
+<Workspace>
+    <Project Language="C#" CommonReferences="true">
+        <Document FilePath="Form1.Designer.cs">
+using System;
+// This file is auto-generated
+class Form1
+{
+    void M() 
+    { 
+        this.Draw$$();
+    }
+}
+        </Document>
+    </Project>
+</Workspace>
+
+            Dim expectedFileWithText =
+                 New Dictionary(Of String, String) From {
+                    {"Form1.Designer.cs",
+<Text>
+using System;
+// This file is auto-generated
+class Form1
+{
+    void M()
+    {
+        this.Draw();
+    }
+
+    private void Draw()
+    {
+        throw new NotImplementedException();
+    }
+}
+</Text>.Value.Trim()}}
+
+            Test(input, fileNameToExpected:=expectedFileWithText)
+        End Sub
+
+        <WorkItem(144843, "Generate method stub generates into *.Designer.cs")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsGenerateMethod)>
+        Public Sub PreferNormalFileOverAutoGeneratedFile_Basic()
+            Dim input =
+<Workspace>
+    <Project Language="Visual Basic" CommonReferences="true">
+        <Document FilePath="Form1.vb">
+Class Form1
+    Sub M() 
+        Dim control As UserControl1
+        control.Draw$$()
+    End Sub
+End Class
+        </Document>
+        <Document FilePath="UserControl1.Designer.vb">
+' This file is auto-generated
+Partial Class UserControl1
+    
+End Class
+        </Document>
+        <Document FilePath="UserControl1.vb">
+Partial Public Class UserControl1
+    
+End Class
+        </Document>
+    </Project>
+</Workspace>
+
+            Dim expectedFileWithText =
+                 New Dictionary(Of String, String) From {
+                    {"UserControl1.vb",
+<Text>
+Partial Public Class UserControl1
+    Friend Sub Draw()
+        Throw New NotImplementedException()
+    End Sub
+End Class
+</Text>.Value.Trim()},
+                    {"UserControl1.Designer.vb",
+<Text>
+' This file is auto-generated
+Partial Class UserControl1
+    
+End Class
+</Text>.Value.Trim()}
+                }
+
+            Test(input, fileNameToExpected:=expectedFileWithText)
+        End Sub
+
+        <WorkItem(144843, "Generate method stub generates into *.Designer.cs")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsGenerateMethod)>
+        Public Sub IntoAutoGeneratedFileIfNoBetterLocationExists_Basic()
+            Dim input =
+<Workspace>
+    <Project Language="Visual Basic" CommonReferences="true">
+        <Document FilePath="Form1.vb">
+Class Form1
+    Sub M() 
+        Dim control As UserControl1
+        control.Draw$$()
+    End Sub
+End Class
+        </Document>
+        <Document FilePath="UserControl1.Designer.vb">
+' This file is auto-generated
+Partial Class UserControl1
+    
+End Class
+        </Document>
+    </Project>
+</Workspace>
+
+            Dim expectedFileWithText =
+                 New Dictionary(Of String, String) From {
+                    {"UserControl1.Designer.vb",
+<Text>
+' This file is auto-generated
+Partial Class UserControl1
+    Friend Sub Draw()
+        Throw New NotImplementedException()
+    End Sub
+End Class
+</Text>.Value.Trim()}}
+
+            Test(input, fileNameToExpected:=expectedFileWithText)
+        End Sub
+
+        <WorkItem(144843, "Generate method stub generates into *.Designer.cs")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsGenerateMethod)>
+        Public Sub InAutoGeneratedFiles_Basic()
+            Dim input =
+<Workspace>
+    <Project Language="Visual Basic" CommonReferences="true">
+        <Document FilePath="Form1.Designer.vb">
+Class Form1
+    Sub M() 
+        Me.Draw$$()
+    End Sub
+End Class
+        </Document>
+    </Project>
+</Workspace>
+
+            Dim expectedFileWithText =
+                 New Dictionary(Of String, String) From {
+                    {"Form1.Designer.vb",
+<Text>
+Class Form1
+    Sub M() 
+        Me.Draw()
+    End Sub
+    Private Sub Draw()
+        Throw New NotImplementedException()
+    End Sub
+End Class
+</Text>.Value.Trim()}}
+
+            Test(input, fileNameToExpected:=expectedFileWithText)
+        End Sub
+
+#End Region
+
     End Class
 End Namespace

src/Workspaces/Core/Portable/CodeGeneration/AbstractCodeGenerationService_FindDeclaration.cs

@@ -6,6 +6,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.GeneratedCodeRecognition;
 using Microsoft.CodeAnalysis.Shared.Extensions;
 using Microsoft.CodeAnalysis.Text;
 using Roslyn.Utilities;
@@ -57,7 +58,8 @@ public bool CanAddTo(SyntaxNode destination, Solution solution, CancellationToke
             return CanAddTo(destination, solution, cancellationToken, out availableIndices);
         }
 
-        private bool CanAddTo(SyntaxNode destination, Solution solution, CancellationToken cancellationToken, out IList<bool> availableIndices)
+        private bool CanAddTo(SyntaxNode destination, Solution solution, CancellationToken cancellationToken,
+            out IList<bool> availableIndices, Func<Document, bool> isGeneratedDocument = null)
         {
             availableIndices = null;
             if (destination == null)
@@ -65,9 +67,6 @@ private bool CanAddTo(SyntaxNode destination, Solution solution, CancellationTok
                 return false;
             }
 
-            // Anything completely hidden is something you can't add to. Anything completely visible
-            // is something you can add to.  Anything that is partially hidden will have to defer to
-            // the underlying language to make a determination.
             var syntaxTree = destination.SyntaxTree;
             var document = solution.GetDocument(syntaxTree);
 
@@ -76,6 +75,15 @@ private bool CanAddTo(SyntaxNode destination, Solution solution, CancellationTok
                 return false;
             }
 
+            // check for generated files if needed.
+            if (isGeneratedDocument != null && isGeneratedDocument(document))
+            {
+                return false;
+            }
+
+            // Anything completely hidden is something you can't add to. Anything completely visible
+            // is something you can add to.  Anything that is partially hidden will have to defer to
+            // the underlying language to make a determination.
             var span = GetSpan(destination);
             if (syntaxTree.IsEntirelyHidden(span, cancellationToken))
             {
@@ -164,16 +172,20 @@ class NestedType
                 }
             }
 
-            // Generate into any decl we can find.
+            // If there is a declaration in a non auto-generated file, prefer it.
+            Func<Document,bool> isGeneratedDocument = 
+                solution.Workspace.Services.GetService<IGeneratedCodeRecognitionService>().IsGeneratedCode;
+
             foreach (var decl in declarations)
             {
                 declaration = await decl.GetSyntaxAsync(cancellationToken).ConfigureAwait(false);
-                if (CanAddTo(declaration, solution, cancellationToken, out availableIndices))
+                if (CanAddTo(declaration, solution, cancellationToken, out availableIndices, isGeneratedDocument))
                 {
                     return Tuple.Create(declaration, availableIndices);
                 }
             }
 
+            // Generate into any declaration we can find.
             availableIndices = null;
             declaration = fallbackDeclaration ?? await SelectFirstOrDefaultAsync(declarations, node => true, cancellationToken).ConfigureAwait(false);