Refactor IsInHeader helpers.

src/Workspaces/CSharp/Portable/LanguageServices/CSharpSyntaxFactsService.cs

@@ -1783,24 +1783,19 @@ public bool IsInPropertyDeclarationHeader(SyntaxNode node)
             {
                 return false;
             }
-            var start = GetStartOfNodeExcludingAttributes(propertyDeclaration);
-            var end = propertyDeclaration.Identifier.FullSpan.End;
 
-            return node.Span.Start >= start && node.Span.End <= end;
+            return IsInHeader(node, propertyDeclaration, propertyDeclaration.Identifier);
         }
 
         public bool IsInParameterHeader(SyntaxNode node)
         {
-            var propertyDeclaration = node.GetAncestorOrThis<ParameterSyntax>();
-            if (propertyDeclaration == null)
+            var parameter = node.GetAncestorOrThis<ParameterSyntax>();
+            if (parameter == null)
             {
                 return false;
             }
 
-            var start = GetStartOfNodeExcludingAttributes(propertyDeclaration);
-            var end = propertyDeclaration.Identifier.FullSpan.End;
-
-            return node.Span.Start >= start && node.Span.End <= end;
+            return IsInHeader(node, parameter, parameter.Identifier);
         }
 
         public bool IsBetweenTypeMembers(SourceText sourceText, SyntaxNode root, int position)

src/Workspaces/Core/Portable/LanguageServices/SyntaxFactsService/AbstractSyntaxFactsService.cs

@@ -488,6 +488,22 @@ public bool SpansPreprocessorDirective(IEnumerable<SyntaxToken> tokens)
         private bool SpansPreprocessorDirective(SyntaxTriviaList list)
             => list.Any(t => IsPreprocessorDirective(t));
 
+        public bool IsInHeader(SyntaxNode node, SyntaxNode ownerOfHeader, SyntaxToken lastTokenOfHeader)
+        {
+            var start = GetStartOfNodeExcludingAttributes(ownerOfHeader);
+            var end = lastTokenOfHeader.FullSpan.End;
+
+            return node.Span.Start >= start && node.Span.End <= end;
+        }
+
+        public bool IsInHeader(SyntaxNode node, SyntaxNode ownerOfHeader, SyntaxNode lastNodeOfHeader)
+        {
+            var start = GetStartOfNodeExcludingAttributes(ownerOfHeader);
+            var end = lastNodeOfHeader.FullSpan.End;
+
+            return node.Span.Start >= start && node.Span.End <= end;
+        }
+
         protected int GetStartOfNodeExcludingAttributes(SyntaxNode node)
         {
             var attributeLists = GetAttributeLists(node);

src/Workspaces/VisualBasic/Portable/LanguageServices/VisualBasicSyntaxFactsService.vb

@@ -1760,9 +1760,11 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
                 Return False
             End If
 
-            Dim start = GetStartOfNodeExcludingAttributes(propertyDeclaration)
-            Dim [end] = If(propertyDeclaration.AsClause?.FullSpan.[End], propertyDeclaration.Identifier.FullSpan.End)
-            Return node.Span.Start >= start AndAlso node.Span.[End] <= [end]
+            If propertyDeclaration.AsClause Is Nothing Then
+                Return IsInHeader(node, propertyDeclaration, propertyDeclaration.AsClause)
+            End If
+
+            Return IsInHeader(node, propertyDeclaration, propertyDeclaration.Identifier)
         End Function
 
         Public Function IsInParameterHeader(node As SyntaxNode) As Boolean Implements ISyntaxFactsService.IsInParameterHeader
@@ -1772,9 +1774,11 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
                 Return False
             End If
 
-            Dim start = GetStartOfNodeExcludingAttributes(parameter)
-            Dim [end] = If(parameter.AsClause?.FullSpan.[End], parameter.Identifier.FullSpan.End)
-            Return node.Span.Start >= start AndAlso node.Span.[End] <= [end]
+            If parameter.AsClause Is Nothing Then
+                Return IsInHeader(node, parameter, parameter.AsClause)
+            End If
+
+            Return IsInHeader(node, parameter, parameter.Identifier)
         End Function
 
         Public Function IsBetweenTypeMembers(sourceText As SourceText, root As SyntaxNode, position As Integer) As Boolean Implements ISyntaxFactsService.IsBetweenTypeMembers