Deprecated load_app().

Adjusted several tests that used it to add apps to the app cache and
then attempted to remove them by manipulating attributes directly.

Also renamed invalid_models to invalid_models_tests to avoid clashing
application labels between the outer and the inner invalid_models
applications.

10 files changed, 47 insertions, 64 deletions

diff --git a/django/core/apps/cache.py b/django/core/apps/cache.py
index 74488325a8..65f51801ec 100644
--- a/django/core/apps/cache.py
+++ b/django/core/apps/cache.py
@@ -133,16 +133,6 @@ class AppCache(object):
 
                 self._models_loaded = True
 
-    def load_app(self, app_name):
-        """
-        Loads the app with the provided fully qualified name, and returns the
-        model module.
-        """
-        app_config = AppConfig(app_name)
-        app_config.import_models(self.all_models[app_config.label])
-        self.app_configs[app_config.label] = app_config
-        return app_config.models_module
-
     def app_cache_ready(self):
         """
         Returns true if the model cache is fully populated.
@@ -377,6 +367,19 @@ class AppCache(object):
 
     ### DEPRECATED METHODS GO BELOW THIS LINE ###
 
+    def load_app(self, app_name):
+        """
+        Loads the app with the provided fully qualified name, and returns the
+        model module.
+        """
+        warnings.warn(
+            "load_app(app_name) is deprecated.",
+            PendingDeprecationWarning, stacklevel=2)
+        app_config = AppConfig(app_name)
+        app_config.import_models(self.all_models[app_config.label])
+        self.app_configs[app_config.label] = app_config
+        return app_config.models_module
+
     def get_app(self, app_label):
         """
         Returns the module containing the models for the given app_label.
@@ -447,7 +450,7 @@ class AppCache(object):
         Register a set of models as belonging to an app.
         """
         warnings.warn(
-            "register_models(app_label, models) is deprecated.",
+            "register_models(app_label, *models) is deprecated.",
             PendingDeprecationWarning, stacklevel=2)
         for model in models:
             self.register_model(app_label, model)
diff --git a/tests/admin_scripts/tests.py b/tests/admin_scripts/tests.py
index db0b8d6030..3f9a336c16 100644
--- a/tests/admin_scripts/tests.py
+++ b/tests/admin_scripts/tests.py
@@ -1094,7 +1094,7 @@ class ManageValidate(AdminScriptTestCase):
         self.assertOutput(err, 'ImportError')
 
     def test_complex_app(self):
-        "manage.py validate does not raise an ImportError validating a complex app with nested calls to load_app"
+        "manage.py validate does not raise an ImportError validating a complex app"
         self.write_settings('settings.py',
             apps=['admin_scripts.complex_app', 'admin_scripts.simple_app'],
             sdict={'DEBUG': True})
diff --git a/tests/app_loading/tests.py b/tests/app_loading/tests.py
index 45f6cd6c31..bb71ad84a2 100644
--- a/tests/app_loading/tests.py
+++ b/tests/app_loading/tests.py
@@ -8,6 +8,7 @@ from django.core.apps import app_cache
 from django.core.apps.cache import AppCache
 from django.test.utils import override_settings
 from django.utils._os import upath
+from django.utils import six
 
 
 class EggLoadingTest(TestCase):
@@ -31,45 +32,41 @@ class EggLoadingTest(TestCase):
         """Models module can be loaded from an app in an egg"""
         egg_name = '%s/modelapp.egg' % self.egg_dir
         sys.path.append(egg_name)
-        models = app_cache.load_app('app_with_models')
-        self.assertFalse(models is None)
+        with app_cache._with_app('app_with_models'):
+            models_module = app_cache.get_app_config('app_with_models').models_module
+            self.assertIsNotNone(models_module)
 
     def test_egg2(self):
         """Loading an app from an egg that has no models returns no models (and no error)"""
         egg_name = '%s/nomodelapp.egg' % self.egg_dir
         sys.path.append(egg_name)
-        models = app_cache.load_app('app_no_models')
-        self.assertTrue(models is None)
+        with app_cache._with_app('app_no_models'):
+            models_module = app_cache.get_app_config('app_no_models').models_module
+            self.assertIsNone(models_module)
 
     def test_egg3(self):
         """Models module can be loaded from an app located under an egg's top-level package"""
         egg_name = '%s/omelet.egg' % self.egg_dir
         sys.path.append(egg_name)
-        models = app_cache.load_app('omelet.app_with_models')
-        self.assertFalse(models is None)
+        with app_cache._with_app('omelet.app_with_models'):
+            models_module = app_cache.get_app_config('app_with_models').models_module
+            self.assertIsNotNone(models_module)
 
     def test_egg4(self):
         """Loading an app with no models from under the top-level egg package generates no error"""
         egg_name = '%s/omelet.egg' % self.egg_dir
         sys.path.append(egg_name)
-        models = app_cache.load_app('omelet.app_no_models')
-        self.assertTrue(models is None)
+        with app_cache._with_app('omelet.app_no_models'):
+            models_module = app_cache.get_app_config('app_no_models').models_module
+            self.assertIsNone(models_module)
 
     def test_egg5(self):
         """Loading an app from an egg that has an import error in its models module raises that error"""
         egg_name = '%s/brokenapp.egg' % self.egg_dir
         sys.path.append(egg_name)
-        self.assertRaises(ImportError, app_cache.load_app, 'broken_app')
-        raised = None
-        try:
-            app_cache.load_app('broken_app')
-        except ImportError as e:
-            raised = e
-
-        # Make sure the message is indicating the actual
-        # problem in the broken app.
-        self.assertTrue(raised is not None)
-        self.assertTrue("modelz" in raised.args[0])
+        with six.assertRaisesRegex(self, ImportError, 'modelz'):
+            with app_cache._with_app('broken_app'):
+                app_cache.get_app_config('omelet.app_no_models').models_module
 
     def test_missing_app(self):
         """
diff --git a/tests/invalid_models/__init__.py b/tests/invalid_models_tests/__init__.py
index e69de29bb2..e69de29bb2 100644
--- a/tests/invalid_models/__init__.py
+++ b/tests/invalid_models_tests/__init__.py
diff --git a/tests/invalid_models/invalid_models/__init__.py b/tests/invalid_models_tests/invalid_models/__init__.py
index e69de29bb2..e69de29bb2 100644
--- a/tests/invalid_models/invalid_models/__init__.py
+++ b/tests/invalid_models_tests/invalid_models/__init__.py
diff --git a/tests/invalid_models/invalid_models/models.py b/tests/invalid_models_tests/invalid_models/models.py
index 0c991dcf13..0c991dcf13 100644
--- a/tests/invalid_models/invalid_models/models.py
+++ b/tests/invalid_models_tests/invalid_models/models.py
diff --git a/tests/invalid_models/tests.py b/tests/invalid_models_tests/tests.py
index 10d8fa47a7..4e0cef546b 100644
--- a/tests/invalid_models/tests.py
+++ b/tests/invalid_models_tests/tests.py
@@ -18,14 +18,7 @@ class InvalidModelTestCase(unittest.TestCase):
         self.stdout = StringIO()
         sys.stdout = self.stdout
 
-        # The models need to be removed after the test in order to prevent bad
-        # interactions with the flush operation in other tests.
-        self._old_models = app_cache.app_configs['invalid_models'].models.copy()
-
     def tearDown(self):
-        app_cache.app_configs['invalid_models'].models = self._old_models
-        app_cache.all_models['invalid_models'] = self._old_models
-        app_cache._get_models_cache = {}
         sys.stdout = self.old_stdout
 
     # Technically, this isn't an override -- TEST_SWAPPED_MODEL must be
@@ -38,12 +31,10 @@ class InvalidModelTestCase(unittest.TestCase):
         TEST_SWAPPED_MODEL_BAD_MODEL='not_an_app.Target',
     )
     def test_invalid_models(self):
-        try:
-            module = app_cache.load_app("invalid_models.invalid_models")
-        except Exception:
-            self.fail('Unable to load invalid model module')
+        with app_cache._with_app("invalid_models_tests.invalid_models"):
+            module = app_cache.get_app_config("invalid_models").models_module
+            get_validation_errors(self.stdout, module)
 
-        get_validation_errors(self.stdout, module)
         self.stdout.seek(0)
         error_log = self.stdout.read()
         actual = error_log.split('\n')
diff --git a/tests/migrations/test_writer.py b/tests/migrations/test_writer.py
index 76fe5b5a9e..f921f9f03c 100644
--- a/tests/migrations/test_writer.py
+++ b/tests/migrations/test_writer.py
@@ -124,8 +124,8 @@ class WriterTests(TestCase):
 
         with override_settings(INSTALLED_APPS=test_apps):
             for app in test_apps:
-                app_cache.load_app(app)
-                migration = migrations.Migration('0001_initial', app.split('.')[-1])
-                expected_path = os.path.join(base_dir, *(app.split('.') + ['migrations', '0001_initial.py']))
-                writer = MigrationWriter(migration)
-                self.assertEqual(writer.path, expected_path)
+                with app_cache._with_app(app):
+                    migration = migrations.Migration('0001_initial', app.split('.')[-1])
+                    expected_path = os.path.join(base_dir, *(app.split('.') + ['migrations', '0001_initial.py']))
+                    writer = MigrationWriter(migration)
+                    self.assertEqual(writer.path, expected_path)
diff --git a/tests/proxy_model_inheritance/tests.py b/tests/proxy_model_inheritance/tests.py
index 601fdc5b42..01a2ddfef6 100644
--- a/tests/proxy_model_inheritance/tests.py
+++ b/tests/proxy_model_inheritance/tests.py
@@ -3,7 +3,6 @@ from __future__ import unicode_literals
 import os
 import sys
 
-from django.conf import settings
 from django.core.apps import app_cache
 from django.core.management import call_command
 from django.test import TestCase, TransactionTestCase
@@ -21,28 +20,21 @@ class ProxyModelInheritanceTests(TransactionTestCase):
     for the proxied model (as described in #12286).  This test creates two dummy
     apps and calls migrate, then verifies that the table has been created.
     """
-
-    available_apps = []
+    available_apps = ['app1', 'app2']
 
     def setUp(self):
         self.old_sys_path = sys.path[:]
         sys.path.append(os.path.dirname(os.path.abspath(upath(__file__))))
-        for app in settings.INSTALLED_APPS:
-            app_cache.load_app(app)
+        self._with_app1 = app_cache._begin_with_app('app1')
+        self._with_app2 = app_cache._begin_with_app('app2')
 
     def tearDown(self):
+        app_cache._end_with_app(self._with_app1)
+        app_cache._end_with_app(self._with_app2)
         sys.path = self.old_sys_path
-        del app_cache.app_configs['app1']
-        del app_cache.app_configs['app2']
-        del app_cache.all_models['app1']
-        del app_cache.all_models['app2']
 
     def test_table_exists(self):
-        try:
-            app_cache.set_available_apps(settings.INSTALLED_APPS)
-            call_command('migrate', verbosity=0)
-        finally:
-            app_cache.unset_available_apps()
+        call_command('migrate', verbosity=0)
         from .app1.models import ProxyModel
         from .app2.models import NiceModel
         self.assertEqual(NiceModel.objects.all().count(), 0)
@@ -56,7 +48,6 @@ class MultiTableInheritanceProxyTest(TestCase):
         Deleting an instance of a model proxying a multi-table inherited
         subclass should cascade delete down the whole inheritance chain (see
         #18083).
-
         """
         instance = ConcreteModelSubclassProxy.objects.create()
         instance.delete()
diff --git a/tests/runtests.py b/tests/runtests.py
index 77cf005267..64d363a095 100755
--- a/tests/runtests.py
+++ b/tests/runtests.py
@@ -164,7 +164,8 @@ def setup(verbosity, test_labels):
         if module_found_in_labels:
             if verbosity >= 2:
                 print("Importing application %s" % module_name)
-            app_cache.load_app(module_label)
+            # HACK.
+            app_cache._begin_with_app(module_label)
             if module_label not in settings.INSTALLED_APPS:
                 settings.INSTALLED_APPS.append(module_label)