Try to fix custom manager in migrations (ref #330, #339, #350).

modeltranslation/tests/tests.py

@@ -27,6 +27,16 @@ except ImportError:
     from django.db.models.loading import AppCache
     NEW_APP_CACHE = False
 
+try:
+    from unittest import skipUnless
+except ImportError:
+    # Dummy replacement for Python 2.6
+    def skipUnless(condition, reason):
+        if not condition:
+            def decorator(test_item):
+                return lambda s: 42
+            return decorator
+        return lambda x: x  # identity
 
 from modeltranslation import admin, settings as mt_settings, translator
 from modeltranslation.forms import TranslationModelForm
@@ -35,6 +45,8 @@ from modeltranslation.tests.test_settings import TEST_SETTINGS
 from modeltranslation.utils import (build_css_class, build_localized_fieldname,
                                     auto_populate, fallbacks)
 
+MIGRATIONS = django.VERSION >= (1, 8)
+
 models = translation = None
 
 # None of the following tests really depend on the content of the request,
@@ -42,7 +54,7 @@ models = translation = None
 request = None
 
 # How many models are registered for tests.
-TEST_MODELS = 29
+TEST_MODELS = 29 + (1 if MIGRATIONS else 0)
 
 
 class reload_override_settings(override_settings):
@@ -131,9 +143,14 @@ class ModeltranslationTransactionTestBase(TransactionTestCase):
                 from modeltranslation.models import handle_translation_registrations
                 handle_translation_registrations()
 
-                # 5. Syncdb (``migrate=False`` in case of south)
+                # 5. makemigrations (``migrate=False`` in case of south)
                 from django.db import connections, DEFAULT_DB_ALIAS
-                cmd = 'syncdb' if django.VERSION < (1, 8) else 'migrate'
+                if MIGRATIONS:
+                    call_command('makemigrations', verbosity=2, interactive=False,
+                                 database=connections[DEFAULT_DB_ALIAS].alias)
+
+                # 6. Syncdb (``migrate=False`` in case of south)
+                cmd = 'migrate' if MIGRATIONS else 'syncdb'
                 call_command(cmd, verbosity=0, migrate=False, interactive=False, run_syncdb=True,
                              database=connections[DEFAULT_DB_ALIAS].alias, load_initial_data=False)
 
@@ -2624,6 +2641,20 @@ class TestManager(ModeltranslationTestBase):
         qs = models.CustomManagerTestModel.objects.custom_qs()
         self.assertIsInstance(qs, MultilingualQuerySet)
 
+    @skipUnless(MIGRATIONS, 'migrations not available')
+    def test_3rd_party_custom_manager(self):
+        from django.contrib.auth.models import Group, GroupManager
+        from modeltranslation.manager import MultilingualManager
+        testmodel_fields = get_field_names(Group)
+        self.assertIn('name',    testmodel_fields)
+        self.assertIn('name_de', testmodel_fields)
+        self.assertIn('name_en', testmodel_fields)
+        self.assertIn('name_en', testmodel_fields)
+
+        self.assertIsInstance(Group.objects, MultilingualManager)
+        self.assertIsInstance(Group.objects, GroupManager)
+        self.assertIn('get_by_natural_key', dir(Group.objects))
+
     def test_multilingual_queryset_pickling(self):
         import pickle
         from modeltranslation.manager import MultilingualQuerySet

modeltranslation/tests/translation.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from django import VERSION
 from django.utils.translation import ugettext_lazy
 
 from modeltranslation.translator import translator, register, TranslationOptions
@@ -203,3 +204,13 @@ translator.register(RequiredModel, RequiredTranslationOptions)
 @register(DecoratedModel)
 class DecoratedTranslationOptions(TranslationOptions):
     fields = ('title',)
+
+
+# ######### 3-rd party with custom manager
+
+if VERSION >= (1, 8):
+    from django.contrib.auth.models import Group
+
+    @register(Group)
+    class GroupTranslationOptions(TranslationOptions):
+        fields = ('name',)

modeltranslation/translator.py

@@ -189,6 +189,18 @@ def add_manager(model):
                                          MultilingualQuerysetManager):
                 use_for_related_fields = getattr(
                     manager.__class__, "use_for_related_fields", not has_custom_queryset(manager))
+                _old_module = manager.__module__
+                _old_class = manager.__class__.__name__
+
+                def deconstruct(self):
+                    return (
+                        False,  # as_manager
+                        '%s.%s' % (self._old_module, self._old_class),  # manager_class
+                        None,  # qs_class
+                        self._constructor_args[0],  # args
+                        self._constructor_args[1],  # kwargs
+                    )
+
             manager.__class__ = NewMultilingualManager
 
     for _, attname, cls in model._meta.concrete_managers + model._meta.abstract_managers:

runtests.py

@@ -37,6 +37,7 @@ def runtests():
             DATABASES=DATABASES,
             INSTALLED_APPS=(
                 'django.contrib.contenttypes',
+                'django.contrib.auth',
                 'modeltranslation',
             ),
             ROOT_URLCONF=None,  # tests override urlconf, but it still needs to be defined