Switch to pytest for unit tests

.coveragerc

@@ -17,6 +17,7 @@ omit =
     cms/djangoapps/contentstore/views/dev.py
     cms/djangoapps/*/migrations/*
     cms/djangoapps/*/features/*
+    cms/lib/*/migrations/*
     lms/debug/*
     lms/envs/*
     lms/djangoapps/*/migrations/*
@@ -25,6 +26,7 @@ omit =
     common/djangoapps/*/migrations/*
     openedx/core/djangoapps/*/migrations/*
     openedx/core/djangoapps/debug/*
+    openedx/features/*/migrations/*
 
 concurrency=multiprocessing
 

.gitignore

@@ -64,6 +64,7 @@ conf/locale/messages.mo
 .testids/
 .noseids
 nosetests.xml
+.cache/
 .coverage
 .coverage.*
 coverage.xml

cms/conftest.py

@@ -0,0 +1,44 @@
+"""
+Studio unit test configuration and fixtures.
+
+This module needs to exist because the pytest.ini in the cms package stops
+pytest from looking for the conftest.py module in the parent directory when
+only running cms tests.
+"""
+
+from __future__ import absolute_import, unicode_literals
+
+import importlib
+import os
+import contracts
+import pytest
+
+
+def pytest_configure(config):
+    """
+    Do core setup operations from manage.py before collecting tests.
+    """
+    if config.getoption('help'):
+        return
+    enable_contracts = os.environ.get('ENABLE_CONTRACTS', False)
+    if not enable_contracts:
+        contracts.disable_all()
+    settings_module = os.environ.get('DJANGO_SETTINGS_MODULE')
+    startup_module = 'cms.startup' if settings_module.startswith('cms') else 'lms.startup'
+    startup = importlib.import_module(startup_module)
+    startup.run()
+
+
+@pytest.fixture(autouse=True, scope='function')
+def _django_clear_site_cache():
+    """
+    pytest-django uses this fixture to automatically clear the Site object
+    cache by replacing it with a new dictionary.  edx-django-sites-extensions
+    grabs the cache dictionary at startup, and uses that one for all lookups
+    from then on.  Our CacheIsolationMixin class tries to clear the cache by
+    grabbing the current dictionary from the site models module and clearing
+    it.  Long story short: if you use this all together, neither cache
+    clearing mechanism actually works.  So override this fixture to not mess
+    with what has been working for us so far.
+    """
+    pass

cms/pytest.ini

@@ -0,0 +1,6 @@
+[pytest]
+DJANGO_SETTINGS_MODULE = cms.envs.test
+addopts = --nomigrations --reuse-db --durations=20 -p no:randomly
+norecursedirs = envs
+python_classes =
+python_files = tests.py test_*.py *_tests.py

common/lib/conftest.py

@@ -0,0 +1,8 @@
+from django.conf import settings
+
+
+def pytest_configure():
+    """
+    Use Django's default settings for tests in common/lib.
+    """
+    settings.configure()

common/lib/pytest.ini

@@ -0,0 +1,5 @@
+[pytest]
+addopts = --nomigrations --reuse-db --durations=20
+norecursedirs = .cache
+python_classes =
+python_files = tests.py test_*.py tests_*.py *_tests.py __init__.py

common/lib/xmodule/xmodule/modulestore/tests/test_split_modulestore.py

@@ -13,12 +13,6 @@
 import ddt
 from contracts import contract
 from nose.plugins.attrib import attr
-# For the cache tests to work, we need to be using the Django default
-# settings (not our usual cms or lms test settings) and they need to
-# be configured before importing from django.core.cache
-from django.conf import settings
-if not settings.configured:
-    settings.configure()
 from django.core.cache import caches, InvalidCacheBackendError
 
 from openedx.core.lib import tempdir

common/test/pytest.ini

@@ -0,0 +1,3 @@
+[pytest]
+addopts = -p no:randomly --durations=20
+norecursedirs = .cache

conftest.py

@@ -0,0 +1,10 @@
+"""
+Default unit test configuration and fixtures.
+"""
+
+from __future__ import absolute_import, unicode_literals
+
+# Import hooks and fixture overrides from the cms package to
+# avoid duplicating the implementation
+
+from cms.conftest import _django_clear_site_cache, pytest_configure  # pylint: disable=unused-import

docs/testing.rst

@@ -130,14 +130,15 @@ however, run any acceptance tests.
 
 Note -
 `paver` is a scripting tool. To get information about various options, you can run the this command.
+
 ::
-	paver -h
+
+    paver -h
+
 Running Python Unit tests
 -------------------------
 
-We use `nose <https://nose.readthedocs.org/en/latest/>`__ through the
-`django-nose plugin <https://pypi.python.org/pypi/django-nose>`__ to run
-the test suite.
+We use `pytest <https://pytest.org/>`__ to run the test suite.
 
 For example, this command runs all the python test scripts.
 
@@ -194,7 +195,7 @@ To run a single django test class use this command.
 
 ::
 
-    paver test_system -t lms/djangoapps/courseware/tests/tests.py:ActivateLoginTest
+    paver test_system -t lms/djangoapps/courseware/tests/tests.py::ActivateLoginTest
 
 When developing tests, it is often helpful to be able to really just run
 one single test without the overhead of PIP installs, UX builds, etc. In
@@ -204,23 +205,23 @@ the time of this writing, the command is the following.
 
 ::
 
-    python ./manage.py lms test --verbosity=1 lms/djangoapps/courseware/tests/test_courses.py   --traceback --settings=test
+    pytest lms/djangoapps/courseware/tests/test_courses.py
 
 
 To run a single test format the command like this.
 
 ::
 
-    paver test_system -t lms/djangoapps/courseware/tests/tests.py:ActivateLoginTest.test_activate_login
+    paver test_system -t lms/djangoapps/courseware/tests/tests.py::ActivateLoginTest::test_activate_login
 
-The ``lms`` suite of tests runs with randomized order, by default.
-You can override these by using ``--no-randomize`` to disable randomization.
+You can use ``--randomize`` to randomize the test case sequence.  In the
+short term, this is likely to reveal bugs in our test setup and teardown;
+please fix (or at least file tickets for) any such issues you encounter.
 
 You can also enable test concurrency with the ``--processes=N`` flag (where ``N``
 is the number of processes to run tests with, and ``-1`` means one process per
 available core). Note, however, that when running concurrently, breakpoints may
-not work correctly, and you will not be able to run single test methods (only
-single test classes).
+not work correctly.
 
 For example:
 
@@ -239,44 +240,44 @@ To re-run all failing django tests from lms or cms, use the
     paver test_system -s lms --failed
     paver test_system -s cms --failed
 
-There is also a ``--fail_fast``, ``-x`` option that will stop nosetests
+There is also a ``--exitfirst``, ``-x`` option that will stop pytest
 after the first failure.
 
 common/lib tests are tested with the ``test_lib`` task, which also
-accepts the ``--failed`` and ``--fail_fast`` options.
+accepts the ``--failed`` and ``--exitfirst`` options.
 
 ::
 
     paver test_lib -l common/lib/calc
     paver test_lib -l common/lib/xmodule --failed
 
-For example, this command runs a single nose test file.
+For example, this command runs a single python unit test file.
 
 ::
 
-    nosetests common/lib/xmodule/xmodule/tests/test_stringify.py
+    pytest common/lib/xmodule/xmodule/tests/test_stringify.py
 
-This command runs a single nose test within a specified file.
+This command runs a single python unit test within a specified file.
 
 ::
 
-    nosetests common/lib/xmodule/xmodule/tests/test_stringify.py:test_stringify
+    pytest common/lib/xmodule/xmodule/tests/test_stringify.py::test_stringify
 
 
-This is an example of how to run a single test and get stdout, with proper env config.
+This is an example of how to run a single test and get stdout shown immediately, with proper env config.
 
 ::
 
-    python manage.py cms --settings test test contentstore.tests.test_import_nostatic -s
+    pytest cms/djangoapps/contentstore/tests/test_import.py -s
 
-These are examples of how to run a single test and get stdout and get coverage.
+These are examples of how to run a single test and get coverage.
 
 ::
 
-    python -m coverage run which ./manage.py cms --settings test test --traceback --logging-clear-handlers --liveserver=localhost:8000-9000 contentstore.tests.test_import_nostatic -s # cms example
-    python -m coverage run which ./manage.py lms --settings test test --traceback --logging-clear-handlers --liveserver=localhost:8000-9000  courseware.tests.test_module_render -s # lms example
+    pytest cms/djangoapps/contentstore/tests/test_import.py --cov # cms example
+    pytest lms/djangoapps/courseware/tests/test_module_render.py --cov # lms example
 
-Use this command to generate coverage report.
+Use this command to generate a coverage report.
 
 ::
 
@@ -297,31 +298,32 @@ you can run one of these commands.
 ::
 
     paver test_system -s cms -t common/djangoapps/terrain/stubs/tests/test_youtube_stub.py
-    python -m coverage run `which ./manage.py` cms --settings test test --traceback common/djangoapps/terrain/stubs/tests/test_youtube_stub.py
+    pytest common/djangoapps/terrain/stubs/tests/test_youtube_stub.py
 
 Very handy: if you pass the ``--pdb`` flag to a paver test function, or
 uncomment the ``pdb=1`` line in ``setup.cfg``, the test runner
 will drop you into pdb on error. This lets you go up and down the stack
 and see what the values of the variables are. Check out `the pdb
-documentation <http://docs.python.org/library/pdb.html>`__
+documentation <http://docs.python.org/library/pdb.html>`__  Note that this
+only works if you aren't collecting coverage statistics (pdb and coverage.py
+use the same mechanism to trace code execution).
 
 Use this command to put a temporary debugging breakpoint in a test.
 If you check this in, your tests will hang on jenkins.
 
 ::
 
-    from nose.tools import set_trace; set_trace()
-
+    import pdb; pdb.set_trace()
 
-Note: More on the ``--failed`` functionality
+Note: More on the ``--failed`` functionality:
 
 * In order to use this, you must run the tests first. If you haven't already
   run the tests, or if no tests failed in the previous run, then using the
   ``--failed`` switch will result in **all** of the tests being run. See more
-  about this in the `nose documentation
-  <http://nose.readthedocs.org/en/latest/plugins/testid.html#looping-over-failed-tests>`__.
+  about this in the `pytest documentation
+  <https://docs.pytest.org/en/latest/cache.html>`__.
 
-* Note that ``paver test_python`` calls nosetests separately for cms and lms.
+* Note that ``paver test_python`` calls pytest separately for cms and lms.
   This means that if tests failed only in lms on the previous run, then calling
   ``paver test_python --failed`` will run **all of the tests for cms** in
   addition to the previously failing lms tests. If you want it to run only the
@@ -501,7 +503,7 @@ To run all the bok choy accessibility tests use this command.
 
     paver test_a11y
 
-To run specific tests, use the ``-t`` flag to specify a nose-style test spec
+To run specific tests, use the ``-t`` flag to specify a pytest-style test spec
 relative to the ``common/test/acceptance/tests`` directory. This is an example for it.
 
 ::
@@ -565,7 +567,7 @@ Note if setup has already been done, you can run::
 You must run BOTH `--testsonly` and `--fasttest`.
 
 3. When done, you can kill your servers in the first terminal/ssh session with
-Control-C. *Warning*: Only hit Control-C one time so the nose test framework can
+Control-C. *Warning*: Only hit Control-C one time so the pytest framework can
 properly clean up.
 
 Running Lettuce Acceptance Tests
@@ -644,7 +646,7 @@ Running Tests on Paver Scripts
 
 To run tests on the scripts that power the various Paver commands, use the following command::
 
-  nosetests pavelib
+  pytest pavelib
 
 
 Testing internationalization with dummy translations
@@ -814,7 +816,7 @@ To view JavaScript code style quality run this command.
 
 ::
 
-	paver run_eslint --limit=50000
+    paver run_eslint --limit=50000
 
 
 

lms/djangoapps/certificates/tests/test_api.py

@@ -207,16 +207,17 @@ def test_with_downloadable_web_cert(self):
         )
 
     @ddt.data(
-        (False, datetime.now(pytz.UTC) + timedelta(days=2), False),
-        (False, datetime.now(pytz.UTC) - timedelta(days=2), True),
-        (True, datetime.now(pytz.UTC) + timedelta(days=2), True)
+        (False, timedelta(days=2), False),
+        (False, -timedelta(days=2), True),
+        (True, timedelta(days=2), True)
     )
     @ddt.unpack
     @patch.dict(settings.FEATURES, {'CERTIFICATES_HTML_VIEW': True})
-    def test_cert_api_return(self, self_paced, cert_avail_date, cert_downloadable_status):
+    def test_cert_api_return(self, self_paced, cert_avail_delta, cert_downloadable_status):
         """
         Test 'downloadable status'
         """
+        cert_avail_date = datetime.now(pytz.UTC) + cert_avail_delta
         self.course.self_paced = self_paced
         self.course.certificate_available_date = cert_avail_date
         self.course.save()

lms/djangoapps/certificates/tests/test_tasks.py

@@ -1,9 +1,7 @@
-from unittest import TestCase
-
 import ddt
+from django.test import TestCase
 from mock import call, patch
 from opaque_keys.edx.keys import CourseKey
-from nose.tools import assert_true
 
 from lms.djangoapps.certificates.tasks import generate_certificate
 from student.tests.factories import UserFactory

lms/djangoapps/courseware/field_overrides.py

@@ -257,6 +257,7 @@ def default(self, block, name):
 
 class OverrideModulestoreFieldData(OverrideFieldData):
     """Apply field data overrides at the modulestore level. No student context required."""
+    provider_classes = None
 
     @classmethod
     def wrap(cls, block, field_data):  # pylint: disable=arguments-differ

lms/djangoapps/courseware/tests/test_module_render.py

@@ -133,6 +133,7 @@ def setUp(self):
         Set up the course and user context
         """
         super(ModuleRenderTestCase, self).setUp()
+        OverrideFieldData.provider_classes = None
 
         self.mock_user = UserFactory()
         self.mock_user.id = 1
@@ -154,6 +155,10 @@ def setUp(self):
             )
         )
 
+    def tearDown(self):
+        OverrideFieldData.provider_classes = None
+        super(ModuleRenderTestCase, self).tearDown()
+
     def test_get_module(self):
         self.assertEqual(
             None,