diff --git a/breakpad.py b/breakpad.py
index ee759f9ce..afe469c6c 100644
--- a/breakpad.py
+++ b/breakpad.py
@@ -89,8 +89,8 @@ def SendStack(last_tb, stack, url=None, maxlen=50):
         'version': sys.version,
     }
     # pylint: disable=W0702
-    print('\n'.join('  %s: %s' % (k, v[0:maxlen])
-                    for k, v in params.iteritems()))
+    print('\n'.join('  %s: %s' % (k, params[k][0:maxlen])
+                    for k in sorted(params)))
     print(post(url, params))
   except IOError:
     print('There was a failure while trying to send the stack trace. Too bad.')
diff --git a/tests/breakpad_unittest.py b/tests/breakpad_unittest.py
new file mode 100755
index 000000000..a561b871a
--- /dev/null
+++ b/tests/breakpad_unittest.py
@@ -0,0 +1,118 @@
+#!/usr/bin/env python
+# Copyright (c) 2011 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Unit tests for breakpad.py."""
+
+# pylint: disable=W0403
+
+# Fixes include path.
+from super_mox import SuperMoxTestBase
+
+import breakpad
+
+
+class Breakpad(SuperMoxTestBase):
+  """Setups and tear downs the mocks but doesn't test anything as-is."""
+  def setUp(self):
+    super(Breakpad, self).setUp()
+    self.mox.StubOutWithMock(breakpad.atexit, 'register')
+    self.mox.StubOutWithMock(breakpad.getpass, 'getuser')
+    self.mox.StubOutWithMock(breakpad.urllib2, 'urlopen')
+    breakpad._HOST_NAME = 'bozo'
+    self._old_sys_argv = breakpad.sys.argv
+    breakpad.sys.argv = ['my_test']
+    self._old_sys_version = breakpad.sys.version
+    breakpad.sys.version = 'random python'
+
+  def tearDown(self):
+    breakpad.sys.version = self._old_sys_version
+    breakpad.sys.argv = self._old_sys_argv
+    super(Breakpad, self).tearDown()
+
+  def testMembersChanged(self):
+    members = [
+        'CheckForException', 'DEFAULT_URL', 'FormatException', 'Register',
+        'SendProfiling', 'SendStack',
+        'atexit', 'getpass', 'os', 'post', 'socket', 'sys', 'time', 'traceback',
+        'urllib', 'urllib2',
+    ]
+    # If this test fails, you should add the relevant test.
+    self.compareMembers(breakpad, members)
+
+  def _part_1_setup_mocks(self, exception):
+    breakpad.os.getcwd().AndReturn('/tmp/asdf')
+    breakpad.getpass.getuser().AndReturn('georges')
+    obj = self.mox.CreateMockAnything()
+    kwargs = {}
+    if (breakpad.sys.version_info[0] * 10 + breakpad.sys.version_info[1]) >= 26:
+      kwargs['timeout'] = 4
+    breakpad.urllib2.urlopen(
+        'https://chromium-status.appspot.com/breakpad',
+        breakpad.urllib.urlencode([('exception', exception)]) + (
+         '&args=%5B%27my_test%27%5D'
+         '&stack=bar'
+         '&host=bozo'
+         '&version=random+python'
+         '&user=georges'
+         '&cwd=%2Ftmp%2Fasdf'),
+        **kwargs).AndReturn(obj)
+    obj.read().AndReturn('ok')
+    obj.close()
+
+  def _part_2_verify_stdout(self, exception):
+    self.checkstdout(
+        ( "Sending crash report ...\n"
+          "  args: ['my_test']\n"
+          "  cwd: /tmp/asdf\n"
+          "  exception: %s\n"
+          "  host: bozo\n"
+          "  stack: bar\n"
+          "  user: georges\n"
+          "  version: random python\n"
+          "ok\n") % exception)
+
+  def _check(self, obj, result):
+    self._part_1_setup_mocks(result)
+    self.mox.ReplayAll()
+    breakpad.SendStack(obj, 'bar')
+    self._part_2_verify_stdout(result)
+
+  def testSendBase(self):
+    self._check('foo', 'foo')
+
+  def testSendReprThrows(self):
+    class Throws(object):
+      def __repr__(self):
+        raise NotImplementedError()
+      def __str__(self):
+        return '[foo]'
+    self._check(Throws(), '[foo]')
+
+  def testSendStrThrows(self):
+    class Throws(object):
+      def __repr__(self):
+        return '[foo]'
+      def __str__(self):
+        raise NotImplementedError()
+    self._check(Throws(), '[foo]')
+
+  def testSendBoth(self):
+    class Both(object):
+      def __repr__(self):
+        return '[foo]'
+      def __str__(self):
+        return '[bar]'
+    self._check(Both(), '[bar]')
+
+  def testSendException(self):
+    obj = Exception('foo')
+    obj.msg = 'a message'
+    self._check(obj, 'foo\nMsg: a message')
+
+
+
+if __name__ == '__main__':
+  import unittest
+  unittest.main()