From effa2597fa89ddca314f25e81c68ab848492e003 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Wed, 30 Aug 2017 16:22:16 -0700
Subject: [PATCH] Cache contextual type for || operator to avoid exponential
 compile time

---
 src/compiler/checker.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index ea88fd2a4b3..a73a29d648d 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -13059,7 +13059,7 @@ namespace ts {
                 // expression has no contextual type, the right operand is contextually typed by the type of the left operand.
                 let type = getContextualType(binaryExpression);
                 if (!type && node === binaryExpression.right) {
-                    type = getTypeOfExpression(binaryExpression.left);
+                    type = getTypeOfExpression(binaryExpression.left, /*cache*/ true);
                 }
                 return type;
             }