Fixed #29817 -- Deprecated settings.FILE_CHARSET.

tests/settings_tests/test_file_charset.py

@@ -0,0 +1,40 @@
+import sys
+from types import ModuleType
+
+from django.conf import FILE_CHARSET_DEPRECATED_MSG, Settings, settings
+from django.test import SimpleTestCase, ignore_warnings
+from django.utils.deprecation import RemovedInDjango31Warning
+
+
+class DeprecationTests(SimpleTestCase):
+    msg = FILE_CHARSET_DEPRECATED_MSG
+
+    def test_override_settings_warning(self):
+        with self.assertRaisesMessage(RemovedInDjango31Warning, self.msg):
+            with self.settings(FILE_CHARSET='latin1'):
+                pass
+
+    def test_settings_init_warning(self):
+        settings_module = ModuleType('fake_settings_module')
+        settings_module.FILE_CHARSET = 'latin1'
+        settings_module.SECRET_KEY = 'ABC'
+        sys.modules['fake_settings_module'] = settings_module
+        try:
+            with self.assertRaisesMessage(RemovedInDjango31Warning, self.msg):
+                Settings('fake_settings_module')
+        finally:
+            del sys.modules['fake_settings_module']
+
+    def test_access_warning(self):
+        with self.assertRaisesMessage(RemovedInDjango31Warning, self.msg):
+            settings.FILE_CHARSET
+        # Works a second time.
+        with self.assertRaisesMessage(RemovedInDjango31Warning, self.msg):
+            settings.FILE_CHARSET
+
+    @ignore_warnings(category=RemovedInDjango31Warning)
+    def test_access(self):
+        with self.settings(FILE_CHARSET='latin1'):
+            self.assertEqual(settings.FILE_CHARSET, 'latin1')
+            # Works a second time.
+            self.assertEqual(settings.FILE_CHARSET, 'latin1')