From 24c8de21c471c2a866a5dff7ce006343bebae52e Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <nathansa@microsoft.com>
Date: Tue, 7 Mar 2017 10:20:02 -0800
Subject: [PATCH] Inline isFlowNarrowable

---
 src/compiler/checker.ts | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index fbd3ac458f0..932b2e9c331 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -10238,13 +10238,9 @@ namespace ts {
             return false;
         }
 
-        function isFlowNarrowable(reference: Node, type: Type, couldBeUninitialized?: boolean) {
-            return reference.flowNode && (type.flags & TypeFlags.Narrowable || couldBeUninitialized);
-        }
-
         function getFlowTypeOfReference(reference: Node, declaredType: Type, initialType = declaredType, flowContainer?: Node, couldBeUninitialized?: boolean) {
             let key: string;
-            if (!isFlowNarrowable(reference, declaredType, couldBeUninitialized)) {
+            if (!reference.flowNode || !couldBeUninitialized && !(declaredType.flags & TypeFlags.Narrowable)) {
                 return declaredType;
             }
             const visitedFlowStart = visitedFlowCount;