Add transformations for model_utils.InheritanceManager. Fix #160

instead of trying to special-case this like we did before I've
added transformation definitions which allow pylint to properly
infer the types of the overriden object managers and know that
they are iterators.

pylint_django/augmentations/__init__.py

@@ -481,30 +481,6 @@ def is_manager_attribute(node):
     return _attribute_is_magic(node, MANAGER_ATTRS.union(QS_ATTRS), parents)
 
 
-def is_model_manager(node):
-    """Checks that node is an attribute named `objects` which usually represents
-       an iterator. This function fixes issues #117.
-    """
-    try:
-        # try to get the model manager node, i.e. 'objects'
-        manager = node.func.expr
-    except:  # noqa: E722, pylint: disable=bare-except
-        return False
-
-#    parents = (
-#        'django.db.models.manager.Manager',
-#        '.Manager',
-#        'django.db.models.query.QuerySet',
-#        '.QuerySet',
-#        'model_utils.managers.InheritanceManager',
-#        'model_utils.managers.QueryManager',
-#        'model_utils.managers.SoftDeletableManager',
-#    )
-    # TODO: properly filter based on class instead of the property name
-    # return _attribute_is_magic(manager, ['objects'], parents)
-    return isinstance(manager, Attribute) and manager.attrname == 'objects'
-
-
 def is_admin_attribute(node):
     """Checks that node is attribute of BaseModelAdmin."""
     parents = ('django.contrib.admin.options.BaseModelAdmin',
@@ -855,8 +831,5 @@ def apply_augmentations(linter):
         # VariablesChecker.leave_module is now wrapped
     # else VariablesChecker.leave_module is already wrapped
 
-    # supress not-an-iterable for model_utils.managers. See #117
-    suppress_message(linter, IterableChecker._check_iterable, 'not-an-iterable', is_model_manager)
-
     # wsgi.py
     suppress_message(linter, _visit_assignname(NameChecker), 'invalid-name', is_wsgi_application)

pylint_django/tests/input/external_model_utils_noerror_override_manager.py

@@ -2,7 +2,7 @@
 # with a manager from the django-model-utils package pylint-django
 # does not report not-an-iterator error, see
 # https://github.com/PyCQA/pylint-django/issues/117
-# pylint: disable=missing-docstring
+# pylint: disable=missing-docstring, invalid-name
 
 from model_utils.managers import InheritanceManager
 
@@ -25,3 +25,12 @@ def function():
 
     for record in BuggyModel.objects.all():
         print(record.name)
+
+
+class Unit(models.Model):
+    sim = models.CharField(max_length=64, null=True, blank=True)
+    objects = InheritanceManager()
+
+
+installed_units = Unit.objects.filter(sim__isnull=False)
+ids = [u.sim for u in installed_units]

pylint_django/transforms/__init__.py

@@ -46,5 +46,9 @@ def set_fake_locals(module):
                'Manager')
 _add_transform('django.utils.translation', 'ugettext_lazy')
 _add_transform('mongoengine', 'Document')
+_add_transform('model_utils.managers',
+               'InheritanceManager',
+               'QueryManager',
+               'SoftDeletableManager')
 # register transform for FileField/ImageField, see #60
 _add_transform('django.db.models.fields.files', 'FileField')

pylint_django/transforms/transforms/django_db_models.py

@@ -40,7 +40,7 @@ class Manager(object):
     get_or_create = __noop
     create = __noop
     bulk_create = __noop
-    filter = __noop
+    filter = __noop_list
     aggregate = __noop
     annotate = __noop
     complex_filter = __noop

pylint_django/transforms/transforms/model_utils_managers.py

@@ -0,0 +1,11 @@
+from django_db_models import Manager
+
+class InheritanceManager(Manager):
+    pass
+
+
+class QueryManager(Manager):
+    pass
+
+class SoftDeletableManager(Manager):
+    pass