Merge pull request #29 from avsd/simple-tests-support

Simple tests support

behave_django/environment.py

@@ -1,8 +1,23 @@
-from behave.runner import ModelRunner
+from behave.runner import ModelRunner, Context
 from django.core.management import call_command
 from django.shortcuts import resolve_url
 
 
+class PatchedContext(Context):
+
+    @property
+    def base_url(self):
+        assert hasattr(self.test, 'live_server_url'), (
+            'Web browser automation is not available.'
+            ' This scenario step can not be run'
+            ' with the --simple or -S flag.')
+        return self.test.live_server_url
+
+    def get_url(self, to=None, *args, **kwargs):
+        return self.base_url + (
+            resolve_url(to, *args, **kwargs) if to else '')
+
+
 class BehaveHooksMixin(object):
     """
     Provides methods that run during test execution
@@ -17,18 +32,15 @@ def before_scenario(self, context):
 
         Sets up the test case, base_url, and the get_url() utility function.
         """
+        context.__class__ = PatchedContext
+        # Simply setting __class__ directly doesn't work
+        # because behave.runner.Context.__setattr__ is implemented wrongly.
+        object.__setattr__(context, '__class__', PatchedContext)
+
         context.test = self.testcase_class()
         context.test.setUpClass()
         context.test()
 
-        context.base_url = context.test.live_server_url
-
-        def get_url(to=None, *args, **kwargs):
-            return context.base_url + (
-                resolve_url(to, *args, **kwargs) if to else '')
-
-        context.get_url = get_url
-
     def load_fixtures(self, context):
         """
         Method that runs immediately after behave's before_scenario function

behave_django/management/commands/behave.py

@@ -7,7 +7,8 @@
 
 from behave_django.environment import monkey_patch_behave
 from behave_django.runner import (BehaviorDrivenTestRunner,
-                                  ExistingDatabaseTestRunner)
+                                  ExistingDatabaseTestRunner,
+                                  SimpleTestRunner)
 
 
 def add_command_arguments(parser):
@@ -26,6 +27,13 @@ def add_command_arguments(parser):
         default=False,
         help="Preserves the test DB between runs.",
     )
+    parser.add_argument(
+        '-S', '--simple',
+        action='store_true',
+        default=False,
+        help="Use simple test runner that supports Django's"
+        " testing client only (no web browser automation)"
+    )
 
 
 def add_behave_arguments(parser):  # noqa
@@ -40,6 +48,8 @@ def add_behave_arguments(parser):  # noqa
         '-c',
         '-k',
         '-v',
+        '-S',
+        '--simple',
     ]
 
     parser.add_argument(
@@ -90,9 +100,18 @@ def add_arguments(self, parser):
 
     def handle(self, *args, **options):
 
+        # Check the flags
+        if options['use_existing_database'] and options['simple']:
+            self.stderr.write(self.style.WARNING(
+                '--simple flag has no effect'
+                ' together with --use-existing-database'
+            ))
+
         # Configure django environment
         if options['dry_run'] or options['use_existing_database']:
             django_test_runner = ExistingDatabaseTestRunner()
+        elif options['simple']:
+            django_test_runner = SimpleTestRunner()
         else:
             django_test_runner = BehaviorDrivenTestRunner()
 

behave_django/runner.py

@@ -2,7 +2,8 @@
 
 from behave_django.environment import BehaveHooksMixin
 from behave_django.testcase import (BehaviorDrivenTestCase,
-                                    ExistingDatabaseTestCase)
+                                    ExistingDatabaseTestCase,
+                                    DjangoSimpleTestCase)
 
 
 class BehaviorDrivenTestRunner(DiscoverRunner, BehaveHooksMixin):
@@ -27,3 +28,11 @@ def setup_databases(self, **kwargs):
 
     def teardown_databases(self, old_config, **kwargs):
         pass
+
+
+class SimpleTestRunner(DiscoverRunner, BehaveHooksMixin):
+    """
+    Test runner that uses DjangoSimpleTestCase with atomic
+    transaction management and no support of web browser automation.
+    """
+    testcase_class = DjangoSimpleTestCase

behave_django/testcase.py

@@ -1,4 +1,5 @@
 from django.contrib.staticfiles.testing import StaticLiveServerTestCase
+from django.test.testcases import TestCase
 
 
 class BehaviorDrivenTestCase(StaticLiveServerTestCase):
@@ -24,3 +25,22 @@ def _fixture_setup(self):
 
     def _fixture_teardown(self):
         pass
+
+
+class DjangoSimpleTestCase(TestCase):
+    """
+    Test case attached to the context during behave execution
+
+    This test case uses `transaction.atomic()` to achieve test isolation
+    instead of flushing the entire database. As a result, tests run much
+    quicker and have no issues with altered DB state after all tests ran
+    when `--keepdb` is used.
+
+    As a side effect, this test case does not support web browser automation.
+    Use Django's testing client instead to test requests and responses.
+
+    Also, it prevents the regular tests from running.
+    """
+
+    def runTest(self):
+        pass

docs/contribute.rst

@@ -17,11 +17,13 @@ Install the dev dependencies
     $ pip install -r requirements-dev.txt
 
 Make sure the tests pass.  The ``@failing`` tag is used for tests that are
-supposed to fail.
+supposed to fail. The ``@requires-live-http`` tag is used for tests that can't run
+with ``--simple`` flag.
 
 .. code:: bash
 
     $ python manage.py behave --tags=~@failing  # skip failing tests
+    $ python manage.py behave --simple --tags=~@failing --tags=~@requires-live-http
     $ py.test
 
 Start your topic branch

docs/usage.rst

@@ -48,6 +48,20 @@ testing client.
         # save response in context for next step
         context.response = context.test.client.get(url)
 
+
+Simple testing
+--------------
+
+If you only use Django's testing client then behave tests can run
+much quicker with the ``--simple`` command line option. In this case
+transaction rollback is used for test automation instead of flushing
+the database after each scenario, just like in Django's standard
+``TestCase``.
+
+No HTTP server is started during the simple testing, so you can't
+use web browser automation. Accessing ``context.base_url``
+or calling ``context.get_url()`` will raise an exception.
+
 unittest + Django assert library
 --------------------------------
 
@@ -162,6 +176,14 @@ recreating it each time you run the test. This flag enables
 ``manage.py behave --keepdb`` to take advantage of that feature.
 |keepdb docs|_.
 
+``--simple``
+************
+
+Use Django's simple ``TestCase`` which rolls back the database transaction after
+each scenario instead of flushing the entire database. Tests run much quicker,
+however HTTP server is not started and therefore web browser automation is
+not available.
+
 Behave configuration file
 -------------------------
 

features/context-urlhelper.feature

@@ -1,3 +1,4 @@
+@requires-live-http
 Feature: URL helpers are available in behave's context
     In order to ensure that url helpers are available as documented
     As the Maintainer

features/live-test-server.feature

@@ -1,3 +1,4 @@
+@requires-live-http
 Feature: Live server
     In order to prove that the live server works
     As the Maintainer

tests/test_cli.py

@@ -12,7 +12,7 @@ def run_silently(command):
         command_args, stdout=PIPE, stderr=PIPE, stdin=PIPE)
     stdout, stderr = process.communicate()
     output = (stdout.decode('UTF-8') + os.linesep +
-              stderr.decode('UTF-8')).strip()
+              stderr.decode('UTF-8')).strip() + os.linesep
     return process.returncode, output
 
 
@@ -25,6 +25,8 @@ def test_additional_management_command_options(self):
             os.linesep + '  --use-existing-database' + os.linesep) in output
         assert (
             os.linesep + '  -k, --keepdb') in output
+        assert (
+            os.linesep + '  -S, --simple') in output
 
     def test_should_accept_behave_arguments(self):
         from behave_django.management.commands.behave import Command
@@ -99,3 +101,15 @@ def test_conflicting_options_should_get_prefixed(self):
             argv=['manage.py', 'behave', '--behave-k', '--behave-version'])
 
         assert args == ['-k', '--version']
+
+    def test_simple_and_use_existing_database_flags_raise_a_warning(self):
+        exit_status, output = run_silently(
+            'python manage.py behave'
+            '    --simple --use-existing-database --tags=@skip-all'
+        )
+        assert exit_status == 0
+        assert (
+            os.linesep +
+            '--simple flag has no effect ' +
+            'together with --use-existing-database' +
+            os.linesep) in output

tests/test_simple_testcase.py

@@ -0,0 +1,42 @@
+try:
+    import unittest.mock as mock
+except ImportError:
+    import mock
+
+from .util import DjangoSetupMixin
+from behave_django.runner import SimpleTestRunner
+from behave.runner import Context, Runner
+from django.test.testcases import TestCase
+import pytest
+
+
+class TestSimpleTestCase(DjangoSetupMixin):
+
+    @mock.patch('behave_django.management.commands.behave.behave_main', return_value=0)  # noqa
+    @mock.patch('behave_django.management.commands.behave.SimpleTestRunner')  # noqa
+    def test_use_simple_test_runner(self,
+                                    mock_simple_test_runner,
+                                    mock_behave_main):
+        self.run_management_command('behave', simple=True)
+        mock_behave_main.assert_called_once_with(args=[])
+        mock_simple_test_runner.assert_called_once_with()
+
+    def test_simple_test_runner_uses_simple_testcase(self):
+        runner = mock.MagicMock()
+        context = Context(runner)
+        SimpleTestRunner().before_scenario(context)
+        assert isinstance(context.test, TestCase)
+
+    def test_simple_testcase_fails_when_accessing_base_url(self):
+        runner = Runner(mock.MagicMock())
+        runner.context = Context(runner)
+        SimpleTestRunner().before_scenario(runner.context)
+        with pytest.raises(AssertionError):
+            assert runner.context.base_url == 'should raise an exception!'
+
+    def test_simple_testcase_fails_when_calling_get_url(self):
+        runner = Runner(mock.MagicMock())
+        runner.context = Context(runner)
+        SimpleTestRunner().before_scenario(runner.context)
+        with pytest.raises(AssertionError):
+            runner.context.get_url()

tox.ini

@@ -25,6 +25,7 @@ deps =
     py27: mock
 commands =
     py.test
+    {envpython} manage.py behave --simple --tags=~@failing --tags=~@requires-live-http --format=progress
     {envpython} manage.py behave --tags=~@failing --format=progress
 
 [testenv:docs]