From 465f1c22637509e1d23e513953a1e96a7691fef2 Mon Sep 17 00:00:00 2001
From: Alexander Korenev <fallforfreedom@gmail.com>
Date: Tue, 3 Jul 2018 10:41:24 +0300
Subject: [PATCH] fix(memory): Add protection against excessive on prop
 patching

  This caused memory leaks in Jest JSDOM environment
---
 lib/common/utils.ts | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/common/utils.ts b/lib/common/utils.ts
index e7bbed307..0af2559b6 100644
--- a/lib/common/utils.ts
+++ b/lib/common/utils.ts
@@ -158,6 +158,11 @@ export function patchProperty(obj: any, prop: string, prototype?: any) {
     return;
   }
 
+  const onPropPatchedSymbol = zoneSymbol('on' + prop + 'patched');
+  if (obj[onPropPatchedSymbol]) {
+    // return;
+  }
+
   // A property descriptor cannot have getter/setter and be writable
   // deleting the writable and value properties avoids this error:
   //
@@ -240,6 +245,8 @@ export function patchProperty(obj: any, prop: string, prototype?: any) {
   };
 
   ObjectDefineProperty(obj, prop, desc);
+
+  obj[onPropPatchedSymbol] = true;
 }
 
 export function patchOnProperties(obj: any, properties: string[]|null, prototype?: any) {