From 8676bbf11ad35c168cf641eb2dfdb6caaad5161c Mon Sep 17 00:00:00 2001
From: Sean Parmelee <seanyp@gmail.com>
Date: Thu, 1 Sep 2016 13:39:25 -0500
Subject: [PATCH] fallback on assignment when a spy cannot be deleted

---
 spec/core/SpyRegistrySpec.js | 25 ++++++++++++++++++++++++-
 src/core/SpyRegistry.js      |  4 +++-
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/spec/core/SpyRegistrySpec.js b/spec/core/SpyRegistrySpec.js
index dc1b1b8b..bbe45903 100644
--- a/spec/core/SpyRegistrySpec.js
+++ b/spec/core/SpyRegistrySpec.js
@@ -127,6 +127,29 @@ describe("SpyRegistry", function() {
 
       expect(subject.hasOwnProperty('spiedFunc')).toBe(false);
       expect(subject.spiedFunc).toBe(originalFunction);
-    })
+    });
+
+    it("restores the original function when it\'s inherited and cannot be deleted", function() {
+      // IE 8 doesn't support `Object.create` or `Object.defineProperty`
+      if (jasmine.getEnv().ieVersion < 9) { return; }
+
+      var spies = [],
+        spyRegistry = new jasmineUnderTest.SpyRegistry({currentSpies: function() { return spies; }}),
+        originalFunction = function() {},
+        subjectParent = {spiedFunc: originalFunction};
+
+      var subject = Object.create(subjectParent);
+
+      spyRegistry.spyOn(subject, 'spiedFunc');
+
+      // simulate a spy that cannot be deleted
+      Object.defineProperty(subject, 'spiedFunc', {
+        configurable: false
+      });
+
+      spyRegistry.clearSpies();
+
+      expect(jasmineUnderTest.isSpy(subject.spiedFunc)).toBe(false);
+    });
   });
 });
diff --git a/src/core/SpyRegistry.js b/src/core/SpyRegistry.js
index 56ffb434..f53bf0ad 100644
--- a/src/core/SpyRegistry.js
+++ b/src/core/SpyRegistry.js
@@ -53,7 +53,9 @@ getJasmineRequireObj().SpyRegistry = function(j$) {
         };
       } else {
         restoreStrategy = function() {
-          delete obj[methodName];
+          if (!delete obj[methodName]) {
+            obj[methodName] = originalMethod;
+          }
         };
       }