--- a/toolkit/system/osxproxy/moz.build
+++ b/toolkit/system/osxproxy/moz.build
@@ -1,12 +1,14 @@
 # -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
 # vim: set filetype=python:
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+TEST_DIRS += ['tests/gtest']
+
 SOURCES += [
     'nsOSXSystemProxySettings.mm',
     'ProxyUtils.mm',
 ]
 
 FINAL_LIBRARY = 'xul'

new file mode 100644
--- /dev/null
+++ b/toolkit/system/osxproxy/tests/gtest/TestProxyBypassRules.cpp
@@ -0,0 +1,41 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "gtest/gtest.h"
+#include "ProxyUtils.h"
+
+using namespace mozilla::toolkit::system;
+
+TEST(OSXProxy, TestProxyBypassRules)
+{
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("mozilla.org"), NS_LITERAL_CSTRING("mozilla.org")));
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("mozilla.org"),NS_LITERAL_CSTRING("*mozilla.org")));
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("mozilla.org"), NS_LITERAL_CSTRING("*.mozilla.org")));
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("www.mozilla.org"), NS_LITERAL_CSTRING("*mozilla.org")));
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("www.mozilla.org"), NS_LITERAL_CSTRING("*.mozilla.org")));
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("www.mozilla.com"), NS_LITERAL_CSTRING("*.mozilla.*")));
+}
+
+TEST(OSXProxy, TestProxyBypassRulesIPv4)
+{
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("192.168.1.1"), NS_LITERAL_CSTRING("192.168.1.*")));
+  EXPECT_FALSE(IsHostProxyEntry(NS_LITERAL_CSTRING("192.168.1.1"), NS_LITERAL_CSTRING("192.168.2.*")));
+
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("10.1.2.3"), NS_LITERAL_CSTRING("10.0.0.0/8")));
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("192.168.192.1"), NS_LITERAL_CSTRING("192.168/16")));
+  EXPECT_FALSE(IsHostProxyEntry(NS_LITERAL_CSTRING("192.168.192.1"), NS_LITERAL_CSTRING("192.168/17")));
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("192.168.192.1"), NS_LITERAL_CSTRING("192.168.128/17")));
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("192.168.1.1"), NS_LITERAL_CSTRING("192.168.1.1/32")));
+}
+
+TEST(OSXProxy, TestProxyBypassRulesIPv6)
+{
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("2001:0DB8:ABCD:0012:0123:4567:89AB:CDEF"), NS_LITERAL_CSTRING("2001:db8:abcd:0012::0/64")));
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("2001:0DB8:ABCD:0012:0000:4567:89AB:CDEF"), NS_LITERAL_CSTRING("2001:db8:abcd:0012::0/80")));
+  EXPECT_FALSE(IsHostProxyEntry(NS_LITERAL_CSTRING("2001:0DB8:ABCD:0012:0123:4567:89AB:CDEF"), NS_LITERAL_CSTRING("2001:db8:abcd:0012::0/80")));
+  EXPECT_TRUE(IsHostProxyEntry(NS_LITERAL_CSTRING("2001:0DB8:ABCD:0012:0000:0000:89AB:CDEF"), NS_LITERAL_CSTRING("2001:db8:abcd:0012::0/96")));
+  EXPECT_FALSE(IsHostProxyEntry(NS_LITERAL_CSTRING("2001:0DB8:ABCD:0012:0123:4567:89AB:CDEF"), NS_LITERAL_CSTRING("2001:db8:abcd:0012::0/96")));
+}

new file mode 100644
--- /dev/null
+++ b/toolkit/system/osxproxy/tests/gtest/moz.build
@@ -0,0 +1,18 @@
+# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, you can obtain one at http://mozilla.org/MPL/2.0/.
+
+UNIFIED_SOURCES += [
+    'TestProxyBypassRules.cpp',
+]
+
+LOCAL_INCLUDES += [
+    '/toolkit/system/osxproxy',
+]
+
+FINAL_LIBRARY = 'xul-gtest'
+
+if CONFIG['GNU_CXX']:
+    CXXFLAGS += ['-Wshadow']