Update utilities.ts

Author: shlomiassaf

src/compiler/utilities.ts

@@ -1118,22 +1118,25 @@ namespace ts {
 
             case SyntaxKind.PropertyDeclaration:
                 // property declarations are valid if their parent is a class declaration.
-                return node.parent.kind === SyntaxKind.ClassDeclaration;
+                return (node.parent && node.parent.kind === SyntaxKind.ClassDeclaration)
+                        || (node.original && node.original.parent.kind === SyntaxKind.ClassDeclaration);
 
             case SyntaxKind.GetAccessor:
             case SyntaxKind.SetAccessor:
             case SyntaxKind.MethodDeclaration:
                 // if this method has a body and its parent is a class declaration, this is a valid target.
                 return (<FunctionLikeDeclaration>node).body !== undefined
-                    && node.parent.kind === SyntaxKind.ClassDeclaration;
+                    && ((node.parent && node.parent.kind === SyntaxKind.ClassDeclaration)
+                        || (node.original && node.original.parent.kind === SyntaxKind.ClassDeclaration));
 
             case SyntaxKind.Parameter:
                 // if the parameter's parent has a body and its grandparent is a class declaration, this is a valid target;
-                return (<FunctionLikeDeclaration>node.parent).body !== undefined
-                    && (node.parent.kind === SyntaxKind.Constructor
-                        || node.parent.kind === SyntaxKind.MethodDeclaration
-                        || node.parent.kind === SyntaxKind.SetAccessor)
-                    && node.parent.parent.kind === SyntaxKind.ClassDeclaration;
+                const parent = node.parent || (node.original && node.original.parent);
+                return parent && (<FunctionLikeDeclaration>parent).body !== undefined
+                    && (parent.kind === SyntaxKind.Constructor
+                        || parent.kind === SyntaxKind.MethodDeclaration
+                        || parent.kind === SyntaxKind.SetAccessor)
+                    && parent.parent.kind === SyntaxKind.ClassDeclaration;
         }
 
         return false;