Migrate test runner to py.test

Migrating test runner from `unittest2`/`nose` to `pytest`.
The pytest runner is also compatible with both unittest and nose tests.
Some of the benefits of PyTest include:
    * using plain asserts
    * function-based fixtures instead of setUp and tearDown
    * no strange camelCase methods

.gitignore

@@ -10,6 +10,7 @@ docs/_build
 
 # Test files
 .tox/
+.cache/
 
 # Django test database
 db.sqlite3

tests/__init__.py

@@ -1,22 +0,0 @@
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-"""Test package set-up."""
-
-from oauth2client import _helpers
-
-__author__ = 'afshar@google.com (Ali Afshar)'
-
-
-def setup_package():
-    """Run on testing package."""
-    _helpers.positional_parameters_enforcement = _helpers.POSITIONAL_EXCEPTION

tests/conftest.py

@@ -0,0 +1,46 @@
+# Copyright 2016 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Common testing tools for OAuth2Client tests."""
+
+import sys
+
+from six.moves import reload_module
+
+from oauth2client import util
+
+
+def set_up_gae_environment(gae_sdk_path):
+    """Set up appengine SDK third-party imports."""
+    if 'google' in sys.modules:
+        # Some packages, such as protobuf, clobber the google
+        # namespace package. This prevents that.
+        reload_module(sys.modules['google'])
+
+    # This sets up google-provided libraries.
+    sys.path.insert(0, gae_sdk_path)
+    import dev_appserver
+    dev_appserver.fix_sys_path()
+
+    # Fixes timezone and other os-level items.
+    import google.appengine.tools.os_compat  # noqa: unused import
+
+
+def pytest_configure(config):
+    """Pytest hook function for setting up test session."""
+    # Set up Google SDK modules unless specified not to
+    if not config.option.no_gae:
+        set_up_gae_environment(config.option.sdk_path)
+    # Default of POSITIONAL_WARNING is too verbose for testing
+    util.positional_parameters_enforcement = util.POSITIONAL_EXCEPTION

tests/contrib/test_appengine.py

@@ -18,10 +18,6 @@ import os
 import tempfile
 import time
 
-import dev_appserver
-
-dev_appserver.fix_sys_path()
-
 from google.appengine.api import apiproxy_stub
 from google.appengine.api import apiproxy_stub_map
 from google.appengine.api import app_identity

tests/test_jwt.py

@@ -235,9 +235,13 @@ class PEMCryptTestsOpenSSL(CryptTests):
 class SignedJwtAssertionCredentialsTests(unittest2.TestCase):
 
     def setUp(self):
+        self.orig_signer = crypt.Signer
         self.format_ = 'p12'
         crypt.Signer = crypt.OpenSSLSigner
 
+    def tearDown(self):
+        crypt.Signer = self.orig_signer
+
     def _make_credentials(self):
         private_key = datafile('privatekey.' + self.format_)
         signer = crypt.Signer.from_string(private_key)
@@ -310,17 +314,25 @@ class PEMSignedJwtAssertionCredentialsOpenSSLTests(
         SignedJwtAssertionCredentialsTests):
 
     def setUp(self):
+        self.orig_signer = crypt.Signer
         self.format_ = 'pem'
         crypt.Signer = crypt.OpenSSLSigner
 
+    def tearDown(self):
+        crypt.Signer = self.orig_signer
+
 
 class PEMSignedJwtAssertionCredentialsPyCryptoTests(
         SignedJwtAssertionCredentialsTests):
 
     def setUp(self):
+        self.orig_signer = crypt.Signer
         self.format_ = 'pem'
         crypt.Signer = crypt.PyCryptoSigner
 
+    def tearDown(self):
+        crypt.Signer = self.orig_signer
+
 
 class TestHasOpenSSLFlag(unittest2.TestCase):
 

tests/test_service_account.py

@@ -45,6 +45,8 @@ def datafile(filename):
 class ServiceAccountCredentialsTests(unittest2.TestCase):
 
     def setUp(self):
+        self.orig_signer = crypt.Signer
+        self.orig_verifier = crypt.Verifier
         self.client_id = '123'
         self.service_account_email = 'dummy@google.com'
         self.private_key_id = 'ABCDEF'
@@ -58,6 +60,10 @@ class ServiceAccountCredentialsTests(unittest2.TestCase):
             client_id=self.client_id,
         )
 
+    def tearDown(self):
+        crypt.Signer = self.orig_signer
+        crypt.Verifier = self.orig_verifier
+
     def test__to_json_override(self):
         signer = object()
         creds = service_account.ServiceAccountCredentials(

tox.ini

@@ -7,7 +7,8 @@ basedeps = mock>=1.3.0
            cryptography>=1.0
            pyopenssl>=0.14
            webtest
-           nose
+           pytest
+           pytest-beds
            flask
            unittest2
            sqlalchemy
@@ -18,60 +19,54 @@ deps = {[testenv]basedeps}
 setenv =
     pypy: with_gmp=no
     DJANGO_SETTINGS_MODULE=tests.contrib.django_util.settings
-commands = nosetests --ignore-files=test_appengine\.py --ignore-files=test__appengine_ndb\.py {posargs}
+commands = 
+    py.test \
+      --no-gae \
+      --ignore=tests/contrib/test_appengine.py \
+      --ignore=tests/contrib/test__appengine_ndb.py \
+      {posargs}
 
 [coverbase]
 basepython = python2.7
 commands =
-    nosetests \
-      --with-coverage \
-      --cover-package=oauth2client \
-      --cover-package=tests \
-      --cover-erase \
-      --cover-tests \
-      --cover-branches \
-      --ignore-files=test_appengine\.py \
-      --ignore-files=test__appengine_ndb\.py
-    nosetests \
-      --with-coverage \
-      --cover-package=oauth2client.contrib.appengine \
-      --cover-package=oauth2client.contrib._appengine_ndb \
-      --cover-package=tests.contrib.test_appengine \
-      --cover-package=tests.contrib.test__appengine_ndb \
-      --with-gae \
-      --cover-tests \
-      --cover-branches \
-      --gae-application=tests/data \
-      --gae-lib-root={env:GAE_PYTHONPATH:google_appengine} \
-      --logging-level=INFO \
+    py.test \
+      --no-gae \
+      --cov=oauth2client \
+      --cov=tests \
+      --ignore=tests/contrib/test_appengine.py \
+      --ignore=tests/contrib/test__appengine_ndb.py
+    py.test \
+      --cov=oauth2client \
+      --cov=tests \
+      --cov-append \
+      --sdk-path={env:GAE_PYTHONPATH:google_appengine} \
       tests/contrib/test_appengine.py \
       tests/contrib/test__appengine_ndb.py
 deps = {[testenv]deps}
     coverage
-    nosegae
+    pytest-cov
 
 [testenv:py33]
 basepython =
     python3.3
 commands =
-    nosetests \
-      --ignore-files=test_appengine\.py \
-      --ignore-files=test__appengine_ndb\.py \
-      --ignore-files=test_django_orm\.py \
-      --ignore-files=test_django_settings\.py \
-      --ignore-files=test_django_util\.py \
-      --exclude-dir=oauth2client/contrib/django_util \
-      --exclude-dir=tests/contrib/django_util \
+    py.test \
+      --no-gae \
+      --ignore=tests/contrib/test_appengine.py \
+      --ignore=tests/contrib/test__appengine_ndb.py \
+      --ignore=tests/contrib/test_django_orm.py \
+      --ignore=tests/contrib/test_django_settings.py \
+      --ignore=oauth2client/contrib/django_util \
+      --ignore=tests/contrib/django_util \
       {posargs}
 deps = {[testenv]basedeps}
        keyring
-       nose-exclude
 
 [testenv:cover]
 basepython = {[coverbase]basepython}
 commands =
     {[coverbase]commands}
-    coverage report --show-missing --cover-min-percentage=100
+    coverage report --show-missing --fail-under=100
 deps =
     {[coverbase]deps}
 
@@ -100,13 +95,9 @@ commands = {toxinidir}/scripts/build_docs.sh
 [testenv:gae]
 basepython = python2.7
 deps = {[testenv]basedeps}
-       nosegae
 commands =
-    nosetests \
-      --with-gae \
-      --gae-lib-root={env:GAE_PYTHONPATH:google_appengine} \
-      --gae-application=tests/data \
-      --logging-level=INFO \
+    py.test \
+      --sdk-path={env:GAE_PYTHONPATH:google_appengine} \
       tests/contrib/test_appengine.py \
       tests/contrib/test__appengine_ndb.py
 
@@ -153,11 +144,8 @@ exclude = .tox,.git,./*.egg,build,
 application-import-names = oauth2client
 putty-ignore =
   # E402 module level import not at top of file
-  # These files have needed configurations defined before import
+  # This file has needed configurations defined before import
   docs/conf.py : E402
-  tests/contrib/test_appengine.py : E402
-  # Additionally, ignore E100 (imports in wrong order) for Django configuration
-  tests/contrib/test_django_orm.py : E402,I100
   # E501 line too long
   # Ignore lines over 80 chars that include "http:" or "https:"
   /http:/ : E501