Remove references to unittest2 library

Library "unittest2" has not released a new version since
Jun 30 2015 [1]. Neutron should remove the references to
this library and point to "unittest" instead.

[1] https://pypi.org/project/unittest2/#history

Change-Id: I7d55adc262280c0c2f13b9b81ecc582e1729afa0
Closes-Bug: #1859190

HACKING.rst

@@ -21,7 +21,6 @@ Below you can find a list of checks specific to this repository.
 - [N331] Detect wrong usage with assertTrue(isinstance()).
 - [N332] Use assertEqual(expected_http_code, observed_http_code) instead of
          assertEqual(observed_http_code, expected_http_code).
-- [N334] Use unittest2 uniformly across Neutron.
 - [N340] Check usage of <module>.i18n (and neutron.i18n)
 - [N341] Check usage of _ from python builtins
 - [N343] Production code must not import from neutron.tests.*
@@ -46,9 +45,7 @@ without the patch and passes with the patch.
 
 All unittest classes must ultimately inherit from testtools.TestCase. In the
 Neutron test suite, this should be done by inheriting from
-neutron.tests.base.BaseTestCase. If the third party unittest library has to
-be used directly then it is recommended to use unittest2 as it contains bug
-fixes to unittest for all versions of Python prior to version 3.5.
+neutron.tests.base.BaseTestCase.
 
 All setUp and tearDown methods must upcall using the super() method.
 tearDown methods should be avoided and addCleanup calls should be preferred.

lower-constraints.txt

@@ -146,7 +146,6 @@ testtools==2.2.0
 tooz==1.58.0
 tinyrpc==0.6
 traceback2==1.4.0
-unittest2==1.1.0
 vine==1.1.4
 waitress==1.1.0
 WebOb==1.8.2

neutron/hacking/checks.py

@@ -15,7 +15,6 @@
 import os
 import re
 
-from hacking import core
 from neutron_lib.hacking import checks
 
 
@@ -42,8 +41,6 @@ def flake8ext(f):
 #    neutron/tests/unit/hacking/test_checks.py
 
 
-unittest_imports_dot = re.compile(r"\bimport[\s]+unittest\b")
-unittest_imports_from = re.compile(r"\bfrom[\s]+unittest\b")
 filter_match = re.compile(r".*filter\(lambda ")
 
 tests_imports_dot = re.compile(r"\bimport[\s]+neutron.tests\b")
@@ -204,17 +201,6 @@ def check_builtins_gettext(logical_line, tokens, filename, lines, noqa):
             yield (0, msg)
 
 
-@core.flake8ext
-@core.off_by_default
-def check_unittest_imports(logical_line):
-    """N334 - Use unittest2 instead of unittest"""
-    if (re.match(unittest_imports_from, logical_line) or
-            re.match(unittest_imports_dot, logical_line)):
-        msg = "N334: '%s' must be used instead of '%s'." % (
-            logical_line.replace('unittest', 'unittest2'), logical_line)
-        yield (0, msg)
-
-
 @flake8ext
 def check_no_imports_from_tests(logical_line, filename, noqa):
     """N343 Production code must not import from neutron.tests.*
@@ -270,7 +256,6 @@ def factory(register):
     register(check_assertequal_for_httpcode)
     register(check_oslo_i18n_wrapper)
     register(check_builtins_gettext)
-    register(check_unittest_imports)
     register(check_no_imports_from_tests)
     register(check_python3_no_filter)
     register(check_no_sqlalchemy_event_import)

neutron/tests/common/base.py

@@ -12,10 +12,10 @@
 #
 
 import functools
+import unittest
 
 from neutron_lib import constants as n_const
 import testtools.testcase
-import unittest2.case
 
 from neutron.common import utils
 from neutron.tests import base
@@ -61,8 +61,7 @@ def no_skip_on_missing_deps(wrapped):
     def wrapper(*args, **kwargs):
         try:
             return wrapped(*args, **kwargs)
-        except (testtools.TestCase.skipException,
-                unittest2.case.SkipTest) as e:
+        except (testtools.TestCase.skipException, unittest.SkipTest) as e:
             if base.bool_from_env('OS_FAIL_ON_MISSING_DEPS'):
                 tools.fail(
                     '%s cannot be skipped because OS_FAIL_ON_MISSING_DEPS '

neutron/tests/functional/pecan_wsgi/__init__.py

@@ -15,16 +15,16 @@
 
 
 import os
+import unittest
 
 from pecan import set_config
 from pecan.testing import load_test_app
-import unittest2
 
 
 __all__ = ['FunctionalTest']
 
 
-class FunctionalTest(unittest2.TestCase):
+class FunctionalTest(unittest.TestCase):
     """Pecan wsgi functional test base class
 
     Used for functional tests where you need to test your

neutron/tests/tools.py

@@ -15,6 +15,7 @@
 
 import datetime
 import random
+import unittest
 
 import fixtures
 import netaddr
@@ -24,7 +25,6 @@ from neutron_lib.utils import helpers
 from neutron_lib.utils import net
 from oslo_utils import netutils
 from oslo_utils import timeutils
-import unittest2
 
 
 # NOTE(yamahata): from neutron-lib 1.9.1, callback priority was added and
@@ -159,7 +159,7 @@ def fail(msg=None):
     This method is equivalent to TestCase.fail without requiring a
     testcase instance (usefully for reducing coupling).
     """
-    raise unittest2.TestCase.failureException(msg)
+    raise unittest.TestCase.failureException(msg)
 
 
 def get_random_string_list(i=3, n=5):

neutron/tests/unit/hacking/test_checks.py

@@ -195,18 +195,6 @@ class HackingTestCase(base.BaseTestCase):
             0, len(list(checks.check_assertequal_for_httpcode(pass_code,
                                         "neutron/tests/test_assert.py"))))
 
-    def test_unittest_imports(self):
-        f = checks.check_unittest_imports
-
-        self.assertLinePasses(f, 'from unittest2')
-        self.assertLinePasses(f, 'import unittest2')
-        self.assertLinePasses(f, 'from unitest2 import case')
-        self.assertLinePasses(f, 'unittest2.TestSuite')
-
-        self.assertLineFails(f, 'from unittest import case')
-        self.assertLineFails(f, 'from unittest.TestSuite')
-        self.assertLineFails(f, 'import unittest')
-
     def test_check_no_imports_from_tests(self):
         fail_codes = ('from neutron import tests',
                       'from neutron.tests import base',

neutron/tests/unit/tests/test_base.py

@@ -16,9 +16,9 @@
 """Tests to test the test framework"""
 
 import sys
+import unittest
 
 import eventlet.timeout
-import unittest2
 
 from neutron.tests import base
 
@@ -62,7 +62,7 @@ class SystemExitTestCase(base.DietTestCase):
     def test_sysexit(self):
         expectedFails = [self.MyTestCase(exitcode) for exitcode in (0, 1)]
 
-        suite = unittest2.TestSuite(tests=expectedFails)
+        suite = unittest.TestSuite(tests=expectedFails)
         result = self.defaultTestResult()
         try:
             suite.run(result)