1 files changed, 12 insertions, 0 deletions
diff --git a/node_modules/es5-ext/test/object/assign-deep.js b/node_modules/es5-ext/test/object/assign-deep.js
index 071eeb739..962ac40df 100644
--- a/node_modules/es5-ext/test/object/assign-deep.js
+++ b/node_modules/es5-ext/test/object/assign-deep.js
@@ -10,6 +10,18 @@ module.exports = function (t, a) {
 
 	var obj1 = { foo: { bar: 3, marko: true } }
 	  , obj2 = { foo: { elo: 12, marko: false }, miszka: [23] };
+
+	var copyObj1 = JSON.parse(JSON.stringify(obj1)), copyObj2 = JSON.parse(JSON.stringify(obj2));
 	a.deep(t({}, obj1, obj2), { foo: { bar: 3, marko: false, elo: 12 }, miszka: [23] });
+	// Ensure it's side effects free
+	a.deep(obj1, copyObj1);
+	a.deep(obj2, copyObj2);
+
+	obj1 = [{ foo: "bar" }];
+	var assignedObj = [];
+	t(assignedObj, obj1);
+	a.deep(assignedObj, [{ foo: "bar" }]);
+	// Ensure array items are copied and not passed
+	a.not(assignedObj[0], obj1[0]);
 	a(t(true), true);
 };