Merge pull request #17868 from CyrusNajmabadi/missingParameterList

VB parameter lists can be missing.  Be resilient to that.

src/Compilers/Core/Portable/Syntax/SyntaxNodeExtensions.cs

@@ -409,9 +409,7 @@ public static SyntaxToken WithoutTrivia(this SyntaxToken token)
         /// <summary>
         /// Creates a new node from this node with the trailing trivia removed.
         /// </summary>
-        public static TSyntax WithoutTrailingTrivia<TSyntax>(
-            this TSyntax node
-            ) where TSyntax : SyntaxNode
+        public static TSyntax WithoutTrailingTrivia<TSyntax>(this TSyntax node) where TSyntax : SyntaxNode
         {
             return node.WithTrailingTrivia((IEnumerable<SyntaxTrivia>)null);
         }

src/EditorFeatures/VisualBasicTest/CodeActions/ReplaceMethodWithProperty/ReplaceMethodWithPropertyTests.vb

@@ -27,6 +27,22 @@ End class",
 End class")
         End Function
 
+        <WorkItem(17368, "https://github.com/dotnet/roslyn/issues/17368")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsReplaceMethodWithProperty)>
+        Public Async Function TestMissingParameterList() As Task
+            Await TestInRegularAndScript1Async(
+"class C
+    function [||]GetFoo as integer
+    End function
+End class",
+"class C
+    ReadOnly Property Foo as integer
+        Get
+        End Get
+    End Property
+End class")
+        End Function
+
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsReplaceMethodWithProperty)>
         Public Async Function TestMethodWithoutGetName() As Task
             Await TestInRegularAndScriptAsync(

src/EditorFeatures/VisualBasicTest/Diagnostics/MakeMethodAsynchronous/MakeMethodAsynchronousTests.vb

@@ -68,8 +68,7 @@ Module Program
     Async Function TestAsync() As Task(Of Integer)
         Await Task.Delay(1)
  Function Sub
- End Module"
-                )
+ End Module")
         End Function
 
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsMakeMethodAsynchronous)>
@@ -389,5 +388,25 @@ End Module
 </File>
             Await TestAsync(initial, expected, ignoreTrivia:=False)
         End Function
+
+        <WorkItem(17368, "https://github.com/dotnet/roslyn/issues/17368")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsMakeMethodAsynchronous)>
+        Public Async Function TestWithMissingParameterList() As Task
+            Await TestInRegularAndScriptAsync(
+"Imports System
+Imports System.Threading.Tasks
+Module Program
+    Sub Test ' Comment
+        [|Await Task.Delay(1)|]
+    End Sub
+End Module",
+"Imports System
+Imports System.Threading.Tasks
+Module Program
+    Async Function TestAsync As Task ' Comment
+        Await Task.Delay(1)
+    End Function
+End Module", ignoreTrivia:=False)
+        End Function
     End Class
 End Namespace
\ No newline at end of file

src/Features/VisualBasic/Portable/MakeMethodAsynchronous/VisualBasicMakeMethodAsynchronousCodeFixProvider.vb

@@ -91,16 +91,19 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.MakeMethodAsynchronous
 
             ' Have to convert this sub into a func. 
             Dim subStatement = node.SubOrFunctionStatement
-            Dim asClause = SyntaxFactory.SimpleAsClause(taskType.GenerateTypeSyntax()).
-                                         WithTrailingTrivia(subStatement.ParameterList.GetTrailingTrivia())
+            Dim asClause =
+                SyntaxFactory.SimpleAsClause(taskType.GenerateTypeSyntax()).
+                              WithTrailingTrivia(
+                                If(subStatement.ParameterList?.GetTrailingTrivia(),
+                                   subStatement.GetTrailingTrivia()))
 
             Dim functionStatement = SyntaxFactory.FunctionStatement(
                 subStatement.AttributeLists,
                 subStatement.Modifiers.Add(s_asyncToken),
                 SyntaxFactory.Token(SyntaxKind.FunctionKeyword).WithTriviaFrom(subStatement.SubOrFunctionKeyword),
-                subStatement.Identifier,
-                subStatement.TypeParameterList,
-                subStatement.ParameterList.WithoutTrailingTrivia(),
+                subStatement.Identifier.WithTrailingTrivia(),
+                subStatement.TypeParameterList?.WithoutTrailingTrivia(),
+                subStatement.ParameterList?.WithoutTrailingTrivia(),
                 asClause,
                 subStatement.HandlesClause,
                 subStatement.ImplementsClause)

src/Features/VisualBasic/Portable/ReplaceMethodWithProperty/VisualBasicReplaceMethodWithPropertyService.vb

@@ -39,8 +39,15 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.CodeRefactorings.ReplaceMethodWithP
                 Return Nothing
             End If
 
-            If position > containingMethod.ParameterList.Span.End Then
-                Return Nothing
+            ' Parameter lists in VB are optional and may not be provided.
+            If containingMethod.ParameterList Is Nothing Then
+                If position > containingMethod.Span.End Then
+                    Return Nothing
+                End If
+            Else
+                If position > containingMethod.ParameterList.Span.End Then
+                    Return Nothing
+                End If
             End If
 
             Return containingMethod