Refs #29713 -- Improved error message from translation system check.

django/core/checks/translation.py

@@ -1,25 +1,19 @@
-import re
-
 from django.conf import settings
 from django.utils.translation.trans_real import language_code_re
 
 from . import Error, Tags, register
 
+E001 = Error(
+    'You have provided an invalid value for the LANGUAGE_CODE setting.',
+    id='translation.E001',
+)
+
 
 @register(Tags.translation)
 def check_setting_language_code(app_configs, **kwargs):
     """
-    Errors if language code is in the wrong format. Language codes specification outlined by
+    Errors if language code setting is invalid.
-    https://en.wikipedia.org/wiki/IETF_language_tag#Syntax_of_language_tags
     """
-    match_result = re.match(language_code_re, settings.LANGUAGE_CODE)
+    if not language_code_re.match(settings.LANGUAGE_CODE):
-    errors = []
+        return [E001]
-    if not match_result:
+    return []
-        errors.append(Error(
-            "LANGUAGE_CODE in settings.py is {}. It should be in the form ll or ll-cc where ll is the language and cc "
-            "is the country. Examples include: it, de-at, es, pt-br. The full set of language codes specifications is "
-            "outlined by https://en.wikipedia.org/wiki/IETF_language_tag#Syntax_of_language_tags".format(
-                settings.LANGUAGE_CODE),
-            id="translation.E001",
-        ))
-    return errors

docs/ref/checks.txt

@@ -85,8 +85,8 @@ Django's system checks are organized using the following tags:
 * ``signals``: Checks on signal declarations and handler registrations.
 * ``staticfiles``: Checks :mod:`django.contrib.staticfiles` configuration.
 * ``templates``: Checks template related configuration.
+* ``translation``: Checks translation related configuration.
 * ``urls``: Checks URL configuration.
-* ``translation``: Checks language formats used for translation.
 
 Some checks may be registered with multiple tags.
 
@@ -427,6 +427,14 @@ configured:
   :setting:`OPTIONS <TEMPLATES-OPTIONS>` must be a string but got: ``{value}``
   (``{type}``).
 
+Translation
+-----------
+
+The following checks are performed on your translation configuration:
+
+* **translation.E001**: You have provided an invalid value for the
+  :setting:`LANGUAGE_CODE` setting.
+
 URLs
 ----
 
@@ -450,18 +458,6 @@ The following checks are performed on your URL configuration:
 * **urls.E006**: The :setting:`MEDIA_URL`/ :setting:`STATIC_URL` setting must
   end with a slash.
 
-Translation
------------
-
-The following checks are performed on your translation configuration:
-
-* **translation.E001**: LANGUAGE_CODE in settings.py is ``<language_code>``.
-   It should be in the form ll or ll-cc where ll is the language and cc is the
-   country. Examples include: ``it``, ``de-at``, ``es``, ``pt-br``. The full
-   set of language codes specifications is outlined by
-   https://en.wikipedia.org/wiki/IETF_language_tag#Syntax_of_language_tags
-
-
 ``contrib`` app checks
 ======================
 

tests/check_framework/test_translation.py

@@ -1,39 +1,41 @@
-from django.core.checks.translation import check_setting_language_code
+from django.core.checks.translation import E001, check_setting_language_code
 from django.test import SimpleTestCase, override_settings
 
 
 class TranslationCheckTests(SimpleTestCase):
 
-    @override_settings(LANGUAGE_CODE="eu")
+    def test_valid_language_code(self):
-    def test_valid_language_code_format_ll_only(self):
+        tags = (
-        result = check_setting_language_code(None)
+            'en',              # language
-        self.assertEqual(len(result), 0)
+            'mas',             # language
+            'sgn-ase',         # language+extlang
+            'fr-CA',           # language+region
+            'es-419',          # language+region
+            'zh-Hans',         # language+script
+            'ca-ES-valencia',  # language+region+variant
+            # FIXME: The following should be invalid:
+            'sr@latin',        # language+script
+        )
+        for tag in tags:
+            with self.subTest(tag), override_settings(LANGUAGE_CODE=tag):
+                self.assertEqual(check_setting_language_code(None), [])
 
-    @override_settings(LANGUAGE_CODE="eü")
+    def test_invalid_language_code(self):
-    def test_invalid_language_code_format_ll_only(self):
+        tags = (
+            'eü',              # non-latin characters.
+            'en_US',           # locale format.
+            'en--us',          # empty subtag.
+            '-en',             # leading separator.
+            'en-',             # trailing separator.
+            'en-US.UTF-8',     # language tag w/ locale encoding.
+            'en_US.UTF-8',     # locale format - languate w/ region and encoding.
+            'ca_ES@valencia',  # locale format - language w/ region and variant.
+            # FIXME: The following should be invalid:
+            # 'sr@latin',      # locale instead of language tag.
+        )
+        for tag in tags:
+            with self.subTest(tag), override_settings(LANGUAGE_CODE=tag):
                 result = check_setting_language_code(None)
-        self.assertEqual(len(result), 1)
+                self.assertEqual(result, [E001])
-        error = result[0]
+                self.assertEqual(result[0].id, 'translation.E001')
-        self.assertEqual(error.id, 'translation.E001')
+                self.assertEqual(result[0].msg, 'You have provided an invalid value for the LANGUAGE_CODE setting.')
-        self.assertEqual(error.msg, (
-            "LANGUAGE_CODE in settings.py is eü. It should be in the form ll or ll-cc where ll is the language and cc "
-            "is the country. Examples include: it, de-at, es, pt-br. The full set of language codes specifications is "
-            "outlined by https://en.wikipedia.org/wiki/IETF_language_tag#Syntax_of_language_tags"
-        ))
-
-    @override_settings(LANGUAGE_CODE="en-US")
-    def test_valid_language_code_format_ll_cc(self):
-        result = check_setting_language_code(None)
-        self.assertEqual(len(result), 0)
-
-    @override_settings(LANGUAGE_CODE="en_US")
-    def test_invalid_language_code_format_ll_cc(self):
-        result = check_setting_language_code(None)
-        self.assertEqual(len(result), 1)
-        error = result[0]
-        self.assertEqual(error.id, 'translation.E001')
-        self.assertEqual(error.msg, (
-            "LANGUAGE_CODE in settings.py is en_US. It should be in the form ll or ll-cc where ll is the language and "
-            "cc is the country. Examples include: it, de-at, es, pt-br. The full set of language codes specifications "
-            "is outlined by https://en.wikipedia.org/wiki/IETF_language_tag#Syntax_of_language_tags"
-        ))