From 35addce79ede5c2f439623401a0fcc2d58943215 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Sat, 19 Aug 2017 09:46:02 +0200
Subject: [PATCH] Add comment

---
 src/compiler/checker.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index d5518eee3d..3c1ed9a949 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -1017,6 +1017,7 @@ namespace ts {
                         }
                         break;
                     case SyntaxKind.ExpressionWithTypeArguments:
+                        // The type parameters of a class are not in scope in the base class expression.
                         if (lastLocation === (<ExpressionWithTypeArguments>location).expression && (<HeritageClause>location.parent).token === SyntaxKind.ExtendsKeyword) {
                             const container = location.parent.parent;
                             if (isClassLike(container) && (result = lookup(getSymbolOfNode(container).members, name, meaning & SymbolFlags.Type))) {