Fixed #31180 -- Configured applications automatically.

18 files changed, 146 insertions, 17 deletions

diff --git a/tests/apps/default_config_app/__init__.py b/tests/apps/default_config_app/__init__.py
deleted file mode 100644
index aebe0350d9..0000000000
--- a/tests/apps/default_config_app/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-default_app_config = 'apps.default_config_app.apps.CustomConfig'
diff --git a/tests/apps/default_config_app/apps.py b/tests/apps/default_config_app/apps.py
deleted file mode 100644
index ba859a4750..0000000000
--- a/tests/apps/default_config_app/apps.py
+++ /dev/null
@@ -1,5 +0,0 @@
-from django.apps import AppConfig
-
-
-class CustomConfig(AppConfig):
-    name = 'apps.default_config_app'
diff --git a/tests/apps/explicit_default_config_app/__init__.py b/tests/apps/explicit_default_config_app/__init__.py
new file mode 100644
index 0000000000..d97f1b3f21
--- /dev/null
+++ b/tests/apps/explicit_default_config_app/__init__.py
@@ -0,0 +1 @@
+default_app_config = 'apps.explicit_default_config_app.apps.ExplicitDefaultConfig'
diff --git a/tests/apps/explicit_default_config_app/apps.py b/tests/apps/explicit_default_config_app/apps.py
new file mode 100644
index 0000000000..e41ad5dcbb
--- /dev/null
+++ b/tests/apps/explicit_default_config_app/apps.py
@@ -0,0 +1,5 @@
+from django.apps import AppConfig
+
+
+class ExplicitDefaultConfig(AppConfig):
+    name = 'apps.explicit_default_config_app'
diff --git a/tests/apps/explicit_default_config_mismatch_app/__init__.py b/tests/apps/explicit_default_config_mismatch_app/__init__.py
new file mode 100644
index 0000000000..8889145538
--- /dev/null
+++ b/tests/apps/explicit_default_config_mismatch_app/__init__.py
@@ -0,0 +1 @@
+default_app_config = 'apps.explicit_default_config_mismatch_app.not_apps.ExplicitDefaultConfigMismatch'
diff --git a/tests/apps/explicit_default_config_mismatch_app/apps.py b/tests/apps/explicit_default_config_mismatch_app/apps.py
new file mode 100644
index 0000000000..ddbead408d
--- /dev/null
+++ b/tests/apps/explicit_default_config_mismatch_app/apps.py
@@ -0,0 +1,5 @@
+from django.apps import AppConfig
+
+
+class ImplicitDefaultConfigMismatch(AppConfig):
+    name = 'apps.explicit_default_config_mismatch_app'
diff --git a/tests/apps/explicit_default_config_mismatch_app/not_apps.py b/tests/apps/explicit_default_config_mismatch_app/not_apps.py
new file mode 100644
index 0000000000..941d35c3d2
--- /dev/null
+++ b/tests/apps/explicit_default_config_mismatch_app/not_apps.py
@@ -0,0 +1,5 @@
+from django.apps import AppConfig
+
+
+class ExplicitDefaultConfigMismatch(AppConfig):
+    name = 'apps.explicit_default_config_mismatch_app'
diff --git a/tests/apps/namespace_package_base/nsapp/apps.py b/tests/apps/namespace_package_base/nsapp/apps.py
index a878449bf9..a81362e5b2 100644
--- a/tests/apps/namespace_package_base/nsapp/apps.py
+++ b/tests/apps/namespace_package_base/nsapp/apps.py
@@ -4,5 +4,6 @@ from django.apps import AppConfig
 
 
 class NSAppConfig(AppConfig):
+    default = False
     name = 'nsapp'
     path = os.path.dirname(__file__)
diff --git a/tests/apps/no_config_app/__init__.py b/tests/apps/no_config_app/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/apps/no_config_app/__init__.py
diff --git a/tests/apps/one_config_app/__init__.py b/tests/apps/one_config_app/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/apps/one_config_app/__init__.py
diff --git a/tests/apps/one_config_app/apps.py b/tests/apps/one_config_app/apps.py
new file mode 100644
index 0000000000..8b44796e42
--- /dev/null
+++ b/tests/apps/one_config_app/apps.py
@@ -0,0 +1,5 @@
+from django.apps import AppConfig
+
+
+class OneConfig(AppConfig):
+    name = 'apps.one_config_app'
diff --git a/tests/apps/tests.py b/tests/apps/tests.py
index 566aec60c3..f4b0a8879b 100644
--- a/tests/apps/tests.py
+++ b/tests/apps/tests.py
@@ -5,11 +5,17 @@ from django.apps.registry import Apps
 from django.contrib.admin.models import LogEntry
 from django.core.exceptions import AppRegistryNotReady, ImproperlyConfigured
 from django.db import models
-from django.test import SimpleTestCase, override_settings
+from django.test import SimpleTestCase, ignore_warnings, override_settings
 from django.test.utils import extend_sys_path, isolate_apps
+from django.utils.deprecation import RemovedInDjango41Warning
 
-from .default_config_app.apps import CustomConfig
+from .explicit_default_config_app.apps import ExplicitDefaultConfig
+from .explicit_default_config_mismatch_app.not_apps import (
+    ExplicitDefaultConfigMismatch,
+)
 from .models import SoAlternative, TotallyNormal, new_apps
+from .one_config_app.apps import OneConfig
+from .two_configs_one_default_app.apps import TwoConfig
 
 # Small list with a variety of cases for tests that iterate on installed apps.
 # Intentionally not in alphabetical order to check if the order is preserved.
@@ -84,25 +90,56 @@ class AppsTests(SimpleTestCase):
                 pass
 
     def test_no_such_app_config(self):
-        msg = "No module named 'apps.NoSuchConfig'"
+        msg = "Module 'apps' does not contain a 'NoSuchConfig' class."
         with self.assertRaisesMessage(ImportError, msg):
             with self.settings(INSTALLED_APPS=['apps.NoSuchConfig']):
                 pass
 
     def test_no_such_app_config_with_choices(self):
         msg = (
-            "'apps.apps' does not contain a class 'NoSuchConfig'. Choices are: "
-            "'BadConfig', 'MyAdmin', 'MyAuth', 'NoSuchApp', 'PlainAppsConfig', "
-            "'RelabeledAppsConfig'."
+            "Module 'apps.apps' does not contain a 'NoSuchConfig' class. "
+            "Choices are: 'BadConfig', 'MyAdmin', 'MyAuth', 'NoSuchApp', "
+            "'PlainAppsConfig', 'RelabeledAppsConfig'."
         )
-        with self.assertRaisesMessage(ImproperlyConfigured, msg):
+        with self.assertRaisesMessage(ImportError, msg):
             with self.settings(INSTALLED_APPS=['apps.apps.NoSuchConfig']):
                 pass
 
-    def test_default_app_config(self):
-        with self.settings(INSTALLED_APPS=['apps.default_config_app']):
-            config = apps.get_app_config('default_config_app')
-        self.assertIsInstance(config, CustomConfig)
+    def test_no_config_app(self):
+        """Load an app that doesn't provide an AppConfig class."""
+        with self.settings(INSTALLED_APPS=['apps.no_config_app']):
+            config = apps.get_app_config('no_config_app')
+        self.assertIsInstance(config, AppConfig)
+
+    def test_one_config_app(self):
+        """Load an app that provides an AppConfig class."""
+        with self.settings(INSTALLED_APPS=['apps.one_config_app']):
+            config = apps.get_app_config('one_config_app')
+        self.assertIsInstance(config, OneConfig)
+
+    def test_two_configs_app(self):
+        """Load an app that provides two AppConfig classes."""
+        with self.settings(INSTALLED_APPS=['apps.two_configs_app']):
+            config = apps.get_app_config('two_configs_app')
+        self.assertIsInstance(config, AppConfig)
+
+    def test_two_default_configs_app(self):
+        """Load an app that provides two default AppConfig classes."""
+        msg = (
+            "'apps.two_default_configs_app.apps' declares more than one "
+            "default AppConfig: 'TwoConfig', 'TwoConfigBis'."
+        )
+        with self.assertRaisesMessage(RuntimeError, msg):
+            with self.settings(INSTALLED_APPS=['apps.two_default_configs_app']):
+                pass
+
+    def test_two_configs_one_default_app(self):
+        """
+        Load an app that provides two AppConfig classes, one being the default.
+        """
+        with self.settings(INSTALLED_APPS=['apps.two_configs_one_default_app']):
+            config = apps.get_app_config('two_configs_one_default_app')
+        self.assertIsInstance(config, TwoConfig)
 
     @override_settings(INSTALLED_APPS=SOME_INSTALLED_APPS)
     def test_get_app_configs(self):
@@ -438,3 +475,48 @@ class NamespacePackageAppTests(SimpleTestCase):
             with self.settings(INSTALLED_APPS=['nsapp.apps.NSAppConfig']):
                 app_config = apps.get_app_config('nsapp')
                 self.assertEqual(app_config.path, self.app_path)
+
+
+class DeprecationTests(SimpleTestCase):
+    @ignore_warnings(category=RemovedInDjango41Warning)
+    def test_explicit_default_app_config(self):
+        with self.settings(INSTALLED_APPS=['apps.explicit_default_config_app']):
+            config = apps.get_app_config('explicit_default_config_app')
+        self.assertIsInstance(config, ExplicitDefaultConfig)
+
+    def test_explicit_default_app_config_warning(self):
+        """
+        Load an app that specifies a default AppConfig class matching the
+        autodetected one.
+        """
+        msg = (
+            "'apps.explicit_default_config_app' defines default_app_config = "
+            "'apps.explicit_default_config_app.apps.ExplicitDefaultConfig'. "
+            "Django now detects this configuration automatically. You can "
+            "remove default_app_config."
+        )
+        with self.assertRaisesMessage(RemovedInDjango41Warning, msg):
+            with self.settings(INSTALLED_APPS=['apps.explicit_default_config_app']):
+                config = apps.get_app_config('explicit_default_config_app')
+            self.assertIsInstance(config, ExplicitDefaultConfig)
+
+    def test_explicit_default_app_config_mismatch(self):
+        """
+        Load an app that specifies a default AppConfig class not matching the
+        autodetected one.
+        """
+        msg = (
+            "'apps.explicit_default_config_mismatch_app' defines "
+            "default_app_config = 'apps.explicit_default_config_mismatch_app."
+            "not_apps.ExplicitDefaultConfigMismatch'. However, Django's "
+            "automatic detection picked another configuration, 'apps."
+            "explicit_default_config_mismatch_app.apps."
+            "ImplicitDefaultConfigMismatch'. You should move the default "
+            "config class to the apps submodule of your application and, if "
+            "this module defines several config classes, mark the default one "
+            "with default = True."
+        )
+        with self.assertRaisesMessage(RemovedInDjango41Warning, msg):
+            with self.settings(INSTALLED_APPS=['apps.explicit_default_config_mismatch_app']):
+                config = apps.get_app_config('explicit_default_config_mismatch_app')
+            self.assertIsInstance(config, ExplicitDefaultConfigMismatch)
diff --git a/tests/apps/two_configs_app/__init__.py b/tests/apps/two_configs_app/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/apps/two_configs_app/__init__.py
diff --git a/tests/apps/two_configs_app/apps.py b/tests/apps/two_configs_app/apps.py
new file mode 100644
index 0000000000..dd2eac9ad1
--- /dev/null
+++ b/tests/apps/two_configs_app/apps.py
@@ -0,0 +1,9 @@
+from django.apps import AppConfig
+
+
+class TwoConfig(AppConfig):
+    name = 'apps.two_configs_app'
+
+
+class TwoConfigBis(AppConfig):
+    name = 'apps.two_configs_app'
diff --git a/tests/apps/two_configs_one_default_app/__init__.py b/tests/apps/two_configs_one_default_app/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/apps/two_configs_one_default_app/__init__.py
diff --git a/tests/apps/two_configs_one_default_app/apps.py b/tests/apps/two_configs_one_default_app/apps.py
new file mode 100644
index 0000000000..489eb0f88f
--- /dev/null
+++ b/tests/apps/two_configs_one_default_app/apps.py
@@ -0,0 +1,10 @@
+from django.apps import AppConfig
+
+
+class TwoConfig(AppConfig):
+    default = True
+    name = 'apps.two_configs_one_default_app'
+
+
+class TwoConfigAlt(AppConfig):
+    name = 'apps.two_configs_one_default_app'
diff --git a/tests/apps/two_default_configs_app/__init__.py b/tests/apps/two_default_configs_app/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/apps/two_default_configs_app/__init__.py
diff --git a/tests/apps/two_default_configs_app/apps.py b/tests/apps/two_default_configs_app/apps.py
new file mode 100644
index 0000000000..3cbcc411b0
--- /dev/null
+++ b/tests/apps/two_default_configs_app/apps.py
@@ -0,0 +1,11 @@
+from django.apps import AppConfig
+
+
+class TwoConfig(AppConfig):
+    default = True
+    name = 'apps.two_default_configs_app'
+
+
+class TwoConfigBis(AppConfig):
+    default = True
+    name = 'apps.two_default_configs_app'