diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma_5/strict/8.12.7.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma_5/strict/8.12.7.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,32 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+function setup() {
+  var o = {all: 1, nowrite: 1, noconfig: 1, noble: 1};
+  Object.defineProperty(o, 'nowrite', {writable: false});
+  Object.defineProperty(o, 'noconfig', {configurable: false});
+  Object.defineProperty(o, 'noble', {writable: false, configurable: false});
+  return o;
+}
+
+assertEq(testLenientAndStrict('var o = setup(); delete o.all',
+                              returns(true), returns(true)),
+         true);
+
+assertEq(testLenientAndStrict('var o = setup(); delete o.nowrite',
+                              returns(true), returns(true)),
+         true);
+
+assertEq(testLenientAndStrict('var o = setup(); delete o.noconfig',
+                              returns(false), raisesException(TypeError)),
+         true);
+
+assertEq(testLenientAndStrict('var o = setup(); delete o.noble',
+                              returns(false), raisesException(TypeError)),
+         true);
+
+reportCompare(true, true);