From 2d1af778396b96411a04f28fba90693f44cc626c Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Thu, 24 Oct 2019 18:30:11 -0400
Subject: [PATCH] Address CR feedback

---
 src/compiler/binder.ts    | 3 ++-
 src/compiler/utilities.ts | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index 6cb9e395f18..fddbffeeecb 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -1,3 +1,4 @@
+
 /* @internal */
 namespace ts {
     export const enum ModuleInstanceState {
@@ -953,7 +954,7 @@ namespace ts {
             }
             if ((expression.kind === SyntaxKind.TrueKeyword && flags & FlowFlags.FalseCondition ||
                 expression.kind === SyntaxKind.FalseKeyword && flags & FlowFlags.TrueCondition) &&
-                !isExpressionOfOptionalChainRoot(expression) && !isQuestionQuestionExpression(expression.parent)) {
+                !isExpressionOfOptionalChainRoot(expression) && !isNullishCoalesce(expression.parent)) {
                 return unreachableFlow;
             }
             if (!isNarrowingExpression(expression)) {
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 7c85f169b72..423fa992504 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -5953,7 +5953,7 @@ namespace ts {
         return isOptionalChainRoot(node.parent) && node.parent.expression === node;
     }
 
-    export function isQuestionQuestionExpression(node: Node) {
+    export function isNullishCoalesce(node: Node) {
         return node.kind === SyntaxKind.BinaryExpression && (<BinaryExpression>node).operatorToken.kind === SyntaxKind.QuestionQuestionToken;
     }