From ef2ecec38c0bfd7aaeba3cca19bb9c74793b7ca2 Mon Sep 17 00:00:00 2001
From: Gyandeep Singh <gyandeeps@gmail.com>
Date: Tue, 20 Jun 2017 02:30:15 -0500
Subject: [PATCH] Check configurable on a prop before creating (fixes #1456)
 (#1462)

* Fix: check configurable on a prop before creating (fixes #1456)
---
 lib/sinon/default-behaviors.js | 15 ++++++++++++---
 test/issues/issues-test.js     | 21 +++++++++++++++++++++
 test/stub-test.js              | 13 +++++++++++++
 3 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/lib/sinon/default-behaviors.js b/lib/sinon/default-behaviors.js
index fcd2422bc..13a8ce7b7 100644
--- a/lib/sinon/default-behaviors.js
+++ b/lib/sinon/default-behaviors.js
@@ -1,4 +1,7 @@
 "use strict";
+
+var getPropertyDescriptor = require("./util/core/get-property-descriptor");
+
 var slice = [].slice;
 var useLeftMostCallback = -1;
 var useRightMostCallback = -2;
@@ -14,6 +17,12 @@ function throwsException(fake, error, message) {
     }
 }
 
+function isPropertyConfigurable(obj, propName) {
+    var propertyDescriptor = getPropertyDescriptor(obj, propName);
+
+    return propertyDescriptor ? propertyDescriptor.configurable : true;
+}
+
 module.exports = {
     callsFake: function callsFake(fake, fn) {
         fake.fakeFn = fn;
@@ -181,7 +190,7 @@ module.exports = {
 
         Object.defineProperty(rootStub.rootObj, rootStub.propName, {
             get: getterFunction,
-            configurable: true
+            configurable: isPropertyConfigurable(rootStub.rootObj, rootStub.propName)
         });
 
         return fake;
@@ -192,7 +201,7 @@ module.exports = {
 
         Object.defineProperty(rootStub.rootObj, rootStub.propName, { // eslint-disable-line accessor-pairs
             set: setterFunction,
-            configurable: true
+            configurable: isPropertyConfigurable(rootStub.rootObj, rootStub.propName)
         });
 
         return fake;
@@ -204,7 +213,7 @@ module.exports = {
         Object.defineProperty(rootStub.rootObj, rootStub.propName, {
             value: newVal,
             enumerable: true,
-            configurable: true
+            configurable: isPropertyConfigurable(rootStub.rootObj, rootStub.propName)
         });
 
         return fake;
diff --git a/test/issues/issues-test.js b/test/issues/issues-test.js
index 4bf67bd3d..6434349e1 100644
--- a/test/issues/issues-test.js
+++ b/test/issues/issues-test.js
@@ -2,6 +2,7 @@
 
 var referee = require("referee");
 var sinon = require("../../lib/sinon");
+var sinonSandbox = require("../../lib/sinon/sandbox");
 var configureLogError = require("../../lib/sinon/util/core/log_error.js");
 var assert = referee.assert;
 var refute = referee.refute;
@@ -248,4 +249,24 @@ describe("issues", function () {
             });
         });
     });
+
+    if (typeof window !== "undefined") {
+        describe("#1456", function () {
+            var sandbox;
+
+            beforeEach(function () {
+                sandbox = sinonSandbox.create();
+            });
+
+            afterEach(function () {
+                sandbox.restore();
+            });
+
+            it("stub window innerHeight", function () {
+                sandbox.stub(window, "innerHeight").value(111);
+
+                assert.equals(window.innerHeight, 111);
+            });
+        });
+    }
 });
diff --git a/test/stub-test.js b/test/stub-test.js
index cfc269d92..e0fd4f1de 100644
--- a/test/stub-test.js
+++ b/test/stub-test.js
@@ -2672,5 +2672,18 @@ describe("stub", function () {
 
             assert.equals(myFunc.prop, "rawString");
         });
+
+        it("allows stubbing object props with configurable false", function () {
+            var myObj = {};
+            Object.defineProperty(myObj, "prop", {
+                configurable: false,
+                enumerable: true,
+                writable: true,
+                value: "static"
+            });
+
+            createStub(myObj, "prop").value("newString");
+            assert.equals(myObj.prop, "newString");
+        });
     });
 });