From d878f80f90cc5376ec1f1198055d0e8634cf7f56 Mon Sep 17 00:00:00 2001
From: Arthur Ozga <aozgaa-ms@outlook.com>
Date: Wed, 1 Mar 2017 11:23:49 -0800
Subject: [PATCH] more rigorous implements-clause check

---
 src/compiler/utilities.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 9eb76405031..37fb48bef05 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -3126,8 +3126,9 @@ namespace ts {
         return tryGetClassExtendingExpressionWithTypeArguments(node) !== undefined;
     }
 
-    export function isExpressionWithTypeArgumentsInClassImplementsClause(node: Node): boolean {
+    export function isExpressionWithTypeArgumentsInClassImplementsClause(node: Node): node is ExpressionWithTypeArguments {
         return node.kind === SyntaxKind.ExpressionWithTypeArguments
+            && isEntityNameExpression((node as ExpressionWithTypeArguments).expression)
             && node.parent
             && (<HeritageClause>node.parent).token === SyntaxKind.ImplementsKeyword
             && node.parent.parent