Merge pull request #42673 from CyrusNajmabadi/genMethOnNullableStruct

Support generate-method on nullable structs.

src/EditorFeatures/CSharpTest/Diagnostics/GenerateMethod/GenerateMethodTests.cs

@@ -6856,6 +6856,35 @@ internal object C()
 }");
         }
 
+        [WorkItem(39001, "https://github.com/dotnet/roslyn/issues/39001")]
+        [WorkItem(1064748, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/1064748")]
+        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsGenerateMethod)]
+        public async Task TestGenerateMethodInConditionalAccess9()
+        {
+            await TestInRegularAndScriptAsync(
+@"struct C
+{
+    void Main(C? c)
+    {
+        int? v = c?.[|Bar|]();
+    }
+}",
+@"using System;
+
+struct C
+{
+    void Main(C? c)
+    {
+        int? v = c?.Bar();
+    }
+
+    private int Bar()
+    {
+        throw new NotImplementedException();
+    }
+}");
+        }
+
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsGenerateMethod)]
         public async Task TestGenerateMethodInPropertyInitializer()
         {

src/EditorFeatures/VisualBasicTest/Diagnostics/GenerateMethod/GenerateMethodTests.vb

@@ -3754,6 +3754,29 @@ End Class",
 index:=1)
         End Function
 
+        <WorkItem(39001, "https://github.com/dotnet/roslyn/issues/39001")>
+        <WorkItem(1064815, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/1064815")>
+        <Fact(), Trait(Traits.Feature, Traits.Features.CodeActionsGenerateMethod)>
+        Public Async Function TestGenerateMethodConditionalAccess5() As Task
+            Await TestInRegularAndScriptAsync(
+"Public Structure C
+    Sub Main(a As C?)
+        Dim x As Integer? = a?[|.B|]()
+    End Sub
+End Structure",
+"Imports System
+
+Public Structure C
+    Sub Main(a As C?)
+        Dim x As Integer? = a?.B()
+    End Sub
+
+    Private Function B() As Integer
+        Throw New NotImplementedException()
+    End Function
+End Structure")
+        End Function
+
         <Fact(), Trait(Traits.Feature, Traits.Features.CodeActionsGenerateMethod)>
         Public Async Function TestGenerateMethodConditionalInPropertyInitializer() As Task
             Await TestInRegularAndScriptAsync(

src/Features/Core/Portable/GenerateMember/AbstractGenerateMemberService.cs

@@ -115,6 +115,11 @@ protected AbstractGenerateMemberService()
                 {
                     DetermineTypeToGenerateInWorker(
                         semanticModel, beforeDotExpression, out typeToGenerateIn, out isStatic, cancellationToken);
+                    if (typeToGenerateIn.IsNullable(out var underlyingType) &&
+                        underlyingType is INamedTypeSymbol underlyingNamedType)
+                    {
+                        typeToGenerateIn = underlyingNamedType;
+                    }
                 }
 
                 return;

src/Features/VisualBasic/Portable/GenerateMember/GenerateParameterizedMember/VisualBasicGenerateMethodService.vb

@@ -83,7 +83,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.GenerateMember.GenerateMethod
             Dim memberAccess = TryCast(simpleName?.Parent, MemberAccessExpressionSyntax)
             Dim conditionalMemberAccessInvocationExpression = TryCast(simpleName?.Parent?.Parent?.Parent, ConditionalAccessExpressionSyntax)
             Dim conditionalMemberAccessSimpleMemberAccess = TryCast(simpleName?.Parent?.Parent, ConditionalAccessExpressionSyntax)
-            If memberAccess?.Name Is simpleName Then
+            If memberAccess?.Name Is simpleName AndAlso memberAccess.Expression IsNot Nothing Then
                 simpleNameOrMemberAccessExpression = memberAccess
             ElseIf TryCast(TryCast(conditionalMemberAccessInvocationExpression?.WhenNotNull, InvocationExpressionSyntax)?.Expression, MemberAccessExpressionSyntax)?.Name Is simpleName Then
                 simpleNameOrMemberAccessExpression = conditionalMemberAccessInvocationExpression