Start using new unittest features from py27/unittest2.

Tornado's test suite now requires unittest2 on py25 and py26.
tornado.testing will use unittest2 if available but does not require
it.

This means we can no longer run the test suite under app engine 2.5,
although it still works for app engine 2.7.

maint/test/appengine/tox.ini

@@ -5,14 +5,18 @@
 # These are currently excluded from the main tox.ini because their
 # logs are spammy and they're a little flaky.
 [tox]
-envlist = py25-appengine, py27-appengine
+envlist = py27-appengine
 
 [testenv]
 changedir = {toxworkdir}
 
+# py25-appengine was broken by the addition of unittest2.  Need to figure
+# out a way to smuggle unittest2 into the appengine environment if we don't
+# drop py25 support.
 [testenv:py25-appengine]
 basepython = python2.5
 commands = python {toxinidir}/py25/runtests.py {posargs:}
+deps = unittest2
 
 [testenv:py27-appengine]
 basepython = python2.7

tornado/test/escape_test.py

@@ -3,10 +3,10 @@
 
 from __future__ import absolute_import, division, with_statement
 import tornado.escape
-import unittest
 
 from tornado.escape import utf8, xhtml_escape, xhtml_unescape, url_escape, url_unescape, to_unicode, json_decode, json_encode
 from tornado.util import b
+from tornado.test.util import unittest
 
 linkify_tests = [
     # (input, linkify_kwargs, expected_output)

tornado/test/httpserver_test.py

@@ -10,6 +10,7 @@ from tornado.ioloop import IOLoop
 from tornado.iostream import IOStream
 from tornado.simple_httpclient import SimpleAsyncHTTPClient
 from tornado.testing import AsyncHTTPTestCase, AsyncHTTPSTestCase, AsyncTestCase, LogTrapTestCase
+from tornado.test.util import unittest
 from tornado.util import b, bytes_type
 from tornado.web import Application, RequestHandler
 import os
@@ -17,7 +18,6 @@ import shutil
 import socket
 import sys
 import tempfile
-import unittest
 
 try:
     import ssl

tornado/test/httputil_test.py

@@ -5,9 +5,9 @@ from __future__ import absolute_import, division, with_statement
 from tornado.httputil import url_concat, parse_multipart_form_data, HTTPHeaders
 from tornado.escape import utf8
 from tornado.testing import LogTrapTestCase
+from tornado.test.util import unittest
 from tornado.util import b
 import logging
-import unittest
 
 
 class TestUrlConcat(unittest.TestCase):

tornado/test/import_test.py

@@ -1,5 +1,5 @@
 from __future__ import absolute_import, division, with_statement
-import unittest
+from tornado.test.util import unittest
 
 
 class ImportTest(unittest.TestCase):

tornado/test/ioloop_test.py

@@ -5,11 +5,11 @@ from __future__ import absolute_import, division, with_statement
 import datetime
 import socket
 import time
-import unittest
 
 from tornado.ioloop import IOLoop
 from tornado.netutil import bind_sockets
 from tornado.testing import AsyncTestCase, LogTrapTestCase, get_unused_port
+from tornado.test.util import unittest
 
 
 class TestIOLoop(AsyncTestCase, LogTrapTestCase):

tornado/test/locale_test.py

@@ -2,7 +2,7 @@ from __future__ import absolute_import, division, with_statement
 
 import os
 import tornado.locale
-import unittest
+from tornado.test.util import unittest
 
 
 class TranslationLoaderTest(unittest.TestCase):

tornado/test/options_test.py

@@ -4,11 +4,11 @@ import logging
 import os
 import re
 import tempfile
-import unittest
 import warnings
 
 from tornado.escape import utf8
 from tornado.options import _Options, _LogFormatter
+from tornado.test.util import unittest
 from tornado.util import b, bytes_type
 
 

tornado/test/runtests.py

@@ -2,7 +2,7 @@
 
 from __future__ import absolute_import, division, with_statement
 import sys
-import unittest
+from tornado.test.util import unittest
 
 TEST_MODULES = [
     'tornado.httputil.doctests',

tornado/test/stack_context_test.py

@@ -3,12 +3,12 @@ from __future__ import absolute_import, division, with_statement
 
 from tornado.stack_context import StackContext, wrap
 from tornado.testing import AsyncHTTPTestCase, AsyncTestCase, LogTrapTestCase
+from tornado.test.util import unittest
 from tornado.util import b
 from tornado.web import asynchronous, Application, RequestHandler
 import contextlib
 import functools
 import logging
-import unittest
 
 
 class TestRequestHandler(RequestHandler):

tornado/test/testing_test.py

@@ -1,9 +1,9 @@
 #!/usr/bin/env python
 
 from __future__ import absolute_import, division, with_statement
-import unittest
 import time
 from tornado.testing import AsyncTestCase, LogTrapTestCase
+from tornado.test.util import unittest
 
 
 class AsyncTestCaseTest(AsyncTestCase, LogTrapTestCase):

tornado/test/twisted_test.py

@@ -25,7 +25,6 @@ import signal
 import tempfile
 import thread
 import threading
-import unittest
 
 try:
     import fcntl
@@ -46,6 +45,7 @@ from tornado.httpclient import AsyncHTTPClient
 from tornado.ioloop import IOLoop
 from tornado.platform.auto import set_close_exec
 from tornado.testing import get_unused_port
+from tornado.test.util import unittest
 from tornado.util import import_object
 from tornado.web import RequestHandler, Application
 

tornado/test/util.py

@@ -0,0 +1,10 @@
+from __future__ import absolute_import, division, with_statement
+
+import sys
+
+# Encapsulate the choice of unittest or unittest2 here.
+# To be used as 'from tornado.test.util import unittest'.
+if sys.version_info >= (2, 7):
+    import unittest
+else:
+    import unittest2 as unittest

tornado/test/util_test.py

@@ -1,8 +1,8 @@
 from __future__ import absolute_import, division, with_statement
 import sys
-import unittest
 
 from tornado.util import raise_exc_info
+from tornado.test.util import unittest
 
 
 class RaiseExcInfoTest(unittest.TestCase):
@@ -23,4 +23,4 @@ class RaiseExcInfoTest(unittest.TestCase):
             raise_exc_info(exc_info)
             self.fail("didn't get expected exception")
         except TwoArgException, e:
-            self.assertTrue(e is exc_info[1])
+            self.assertIs(e, exc_info[1])

tornado/testing.py

@@ -41,7 +41,15 @@ import os
 import signal
 import sys
 import time
-import unittest
+
+# Tornado's own test suite requires the updated unittest module
+# (either py27+ or unittest2) so tornado.test.util enforces
+# this requirement, but for other users of tornado.testing we want
+# to allow the older version if unitest2 is not available.
+try:
+    import unittest2 as unittest
+except ImportError:
+    import unittest
 
 _next_port = 10000
 

tox.ini

@@ -28,7 +28,9 @@ changedir = {toxworkdir}
 
 [testenv:py25]
 basepython = python2.5
-deps = simplejson
+deps =
+     simplejson
+     unittest2
 
 [testenv:py25-full]
 basepython = python2.5
@@ -38,9 +40,14 @@ deps =
      simplejson
      # twisted is dropping python 2.5 support in 12.2.0
      twisted<=12.1.0
+     unittest2
      # zope.interface (used by twisted) dropped python 2.5 support in 4.0
      zope.interface<4.0
 
+[testenv:py26]
+basepython = python2.6
+deps = unittest2
+
 # py26-full deliberately runs an older version of twisted to ensure
 # we're still compatible with the oldest version we support.
 [testenv:py26-full]
@@ -49,6 +56,7 @@ deps =
      MySQL-python
      pycurl
      twisted==11.0.0
+     unittest2
 
 [testenv:py27-full]
 basepython = python2.7