From 505c153fed9e45905c8e9d61f7a8d6fae3d11c29 Mon Sep 17 00:00:00 2001
From: Mohamed Hegazy <mhegazy@microsoft.com>
Date: Tue, 29 Nov 2016 16:57:37 -0800
Subject: [PATCH] Simplify isValidSpreadType

---
 src/compiler/checker.ts | 18 +++---------------
 1 file changed, 3 insertions(+), 15 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 56112fe7e86..7dc1ea57708 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -11539,21 +11539,9 @@ namespace ts {
        }
 
         function isValidSpreadType(type: Type): boolean {
-            if (type.flags & (TypeFlags.Any | TypeFlags.Null | TypeFlags.Undefined)) {
-                return true;
-            }
-            if (type.flags & TypeFlags.Object) {
-                return !isGenericMappedType(type);
-            }
-            else if (type.flags & TypeFlags.UnionOrIntersection) {
-                for (const t of (<UnionOrIntersectionType>type).types) {
-                    if (!isValidSpreadType(t)) {
-                        return false;
-                    }
-                }
-                return true;
-            }
-            return false;
+            return !!(type.flags & (TypeFlags.Any | TypeFlags.Null | TypeFlags.Undefined) ||
+                type.flags & TypeFlags.Object && !isGenericMappedType(type) ||
+                type.flags & TypeFlags.UnionOrIntersection && !forEach((<UnionOrIntersectionType>type).types, t => !isValidSpreadType(t)));
         }
 
         function checkJsxSelfClosingElement(node: JsxSelfClosingElement) {