Fix generate type dialog invoked on type argument in a base list

src/EditorFeatures/CSharpTest/CodeActions/GenerateType/GenerateTypeTests_Dialog.cs

@@ -2271,6 +2271,104 @@ public struct Bar
 isNewFile: false,
 assertGenerateTypeDialogOptions: new GenerateTypeDialogOptions(false, TypeKindOptions.Class | TypeKindOptions.Structure, false));
     }
+
+    [Fact, WorkItem(63280, "https://github.com/dotnet/roslyn/issues/63280")]
+    public async Task GenerateType_GenericBaseList()
+    {
+        await TestWithMockedGenerateTypeDialog(
+initial: @"
+using System.Collections.Generic;
+
+struct C : IEnumerable<[|$$NewType|]>
+{
+}",
+languageName: LanguageNames.CSharp,
+typeName: "NewType",
+expected: @"
+using System.Collections.Generic;
+
+struct C : IEnumerable<NewType>
+{
+}
+
+public class NewType
+{
+}",
+accessibility: Accessibility.Public,
+typeKind: TypeKind.Class,
+isNewFile: false,
+assertGenerateTypeDialogOptions: new GenerateTypeDialogOptions(false, TypeKindOptions.AllOptions, false));
+    }
+
+    [Fact]
+    public async Task GenerateType_QualifiedBaseList()
+    {
+        await TestWithMockedGenerateTypeDialog(
+initial: @"
+using System.Collections.Generic;
+
+struct C : A.B.[|$$INewType|]
+{
+}
+
+namespace A.B
+{
+}",
+languageName: LanguageNames.CSharp,
+typeName: "INewType",
+expected: @"
+using System.Collections.Generic;
+
+struct C : A.B.INewType
+{
+}
+
+namespace A.B
+{
+    public interface INewType
+    {
+    }
+}",
+accessibility: Accessibility.Public,
+typeKind: TypeKind.Interface,
+isNewFile: false,
+assertGenerateTypeDialogOptions: new GenerateTypeDialogOptions(false, TypeKindOptions.Interface, false));
+    }
+
+    [Fact]
+    public async Task GenerateType_AliasQualifiedBaseList()
+    {
+        await TestWithMockedGenerateTypeDialog(
+initial: @"
+using System.Collections.Generic;
+
+struct C : global::A.B.[|$$INewType|]
+{
+}
+
+namespace A.B
+{
+}",
+languageName: LanguageNames.CSharp,
+typeName: "INewType",
+expected: @"
+using System.Collections.Generic;
+
+struct C : global::A.B.INewType
+{
+}
+
+namespace A.B
+{
+    public interface INewType
+    {
+    }
+}",
+accessibility: Accessibility.Public,
+typeKind: TypeKind.Interface,
+isNewFile: false,
+assertGenerateTypeDialogOptions: new GenerateTypeDialogOptions(false, TypeKindOptions.Interface, false));
+    }
     #endregion
     #region Delegates
     [Fact]

src/EditorFeatures/DiagnosticsTestUtilities/Diagnostics/AbstractUserDiagnosticTest_GenerateTypeDialog.cs

@@ -167,9 +167,9 @@ await TestOperationsAsync(testState.Workspace, expectedTextWithUsings, operation
 
                 if (assertGenerateTypeDialogOptions != null)
                 {
-                    Assert.True(assertGenerateTypeDialogOptions.IsPublicOnlyAccessibility == generateTypeDialogOptions.IsPublicOnlyAccessibility);
-                    Assert.True(assertGenerateTypeDialogOptions.TypeKindOptions == generateTypeDialogOptions.TypeKindOptions);
-                    Assert.True(assertGenerateTypeDialogOptions.IsAttribute == generateTypeDialogOptions.IsAttribute);
+                    Assert.Equal(assertGenerateTypeDialogOptions.IsPublicOnlyAccessibility, generateTypeDialogOptions.IsPublicOnlyAccessibility);
+                    Assert.Equal(assertGenerateTypeDialogOptions.TypeKindOptions, generateTypeDialogOptions.TypeKindOptions);
+                    Assert.Equal(assertGenerateTypeDialogOptions.IsAttribute, generateTypeDialogOptions.IsAttribute);
                 }
 
                 if (assertTypeKindPresent != null)

src/EditorFeatures/VisualBasicTest/CodeActions/GenerateType/GenerateTypeTests_Dialog.vb

@@ -1626,6 +1626,37 @@ typeName:="Bar",
 isMissing:=True)
         End Function
 
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsGenerateType)>
+        <WorkItem(63280, "https://github.com/dotnet/roslyn/issues/63280")>
+        Public Async Function GenerateType_GenericBaseList() As Task
+            Await TestWithMockedGenerateTypeDialog(
+initial:=<Text>
+Imports System.Collections.Generic
+
+Structure S
+    Implements IEnumerable(Of [|$$NewType|])
+
+End Structure
+</Text>.NormalizedValue,
+languageName:=LanguageNames.VisualBasic,
+typeName:="NewType",
+expected:=<Text>
+Imports System.Collections.Generic
+
+Structure S
+    Implements IEnumerable(Of NewType)
+
+End Structure
+
+Public Class NewType
+End Class
+</Text>.NormalizedValue,
+isNewFile:=False,
+accessibility:=Accessibility.Public,
+typeKind:=TypeKind.Class,
+assertGenerateTypeDialogOptions:=New GenerateTypeDialogOptions(False, TypeKindOptions.AllOptions, False))
+        End Function
+
 #End Region
 #Region "Delegates"
         <Fact>

src/Features/CSharp/Portable/GenerateType/CSharpGenerateTypeService.cs

@@ -664,23 +664,16 @@ internal override bool TryGetBaseList(ExpressionSyntax expression, out TypeKindO
             return false;
         }
 
-        var node = expression as SyntaxNode;
-
-        while (node != null)
+        if (expression.Parent is BaseTypeSyntax { Parent: BaseListSyntax baseList })
         {
-            if (node is BaseListSyntax)
+            if (baseList.Parent.Kind() is SyntaxKind.InterfaceDeclaration or SyntaxKind.StructDeclaration or SyntaxKind.RecordStructDeclaration)
             {
-                if (node.Parent.Kind() is SyntaxKind.InterfaceDeclaration or SyntaxKind.StructDeclaration or SyntaxKind.RecordStructDeclaration)
-                {
-                    typeKindValue = TypeKindOptions.Interface;
-                    return true;
-                }
-
-                typeKindValue = TypeKindOptions.BaseList;
+                typeKindValue = TypeKindOptions.Interface;
                 return true;
             }
 
-            node = node.Parent;
+            typeKindValue = TypeKindOptions.BaseList;
+            return true;
         }
 
         return false;

src/Features/Core/Portable/GenerateType/AbstractGenerateTypeService.CodeAction.cs

@@ -140,8 +140,7 @@ private bool GetPredefinedTypeKindOption(State state, out TypeKindOptions typeKi
                 return true;
             }
 
-            if (_service.TryGetBaseList(state.NameOrMemberAccessExpression, out var typeKindValue) ||
-                _service.TryGetBaseList(state.SimpleName, out typeKindValue))
+            if (_service.TryGetBaseList(state.NameOrMemberAccessExpression, out var typeKindValue))
             {
                 typeKindValueFinal = typeKindValue;
                 return true;

src/Features/VisualBasic/Portable/GenerateType/VisualBasicGenerateTypeService.vb

@@ -539,23 +539,18 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.GenerateType
                 Return False
             End If
 
-            Dim node As SyntaxNode = expression
-            While node IsNot Nothing
-                If TypeOf node Is InheritsStatementSyntax Then
-                    If node.Parent IsNot Nothing AndAlso TypeOf node.Parent Is InterfaceBlockSyntax Then
-                        typeKindValue = TypeKindOptions.Interface
-                        Return True
-                    End If
-
-                    typeKindValue = TypeKindOptions.Class
-                    Return True
-                ElseIf TypeOf node Is ImplementsStatementSyntax Then
+            If TypeOf expression.Parent Is InheritsStatementSyntax Then
+                If expression.Parent.Parent IsNot Nothing AndAlso TypeOf expression.Parent.Parent Is InterfaceBlockSyntax Then
                     typeKindValue = TypeKindOptions.Interface
                     Return True
                 End If
 
-                node = node.Parent
-            End While
+                typeKindValue = TypeKindOptions.Class
+                Return True
+            ElseIf TypeOf expression.Parent Is ImplementsStatementSyntax Then
+                typeKindValue = TypeKindOptions.Interface
+                Return True
+            End If
 
             Return False
         End Function