Use py__get__ for Django Model.objects

This includes the fix in typeddjango/django-stubs#394

jedi/inference/base_value.py

@@ -240,6 +240,9 @@ def py__get__(self, instance, class_value):
         debug.warning("No __get__ defined on %s", self)
         return ValueSet([self])
 
+    def py__get__on_class(self, calling_instance, instance, class_value):
+        return NotImplemented
+
     def get_qualified_names(self):
         # Returns Optional[Tuple[str, ...]]
         return None

jedi/inference/gradual/base.py

@@ -200,6 +200,9 @@ def is_sub_class_of(self, class_value):
             return True
         return self._class_value.is_sub_class_of(class_value)
 
+    def with_generics(self, generics_tuple):
+        return self._class_value.with_generics(generics_tuple)
+
     def infer_type_vars(self, value_set):
         # Circular
         from jedi.inference.gradual.annotation import merge_pairwise_generics, merge_type_var_dicts
@@ -287,6 +290,9 @@ def _remap_type_vars(self, base):
                     new |= ValueSet([type_var])
             yield new
 
+    def __repr__(self):
+        return '<%s: %s>' % (self.__class__.__name__, self._lazy_base_class)
+
 
 class _GenericInstanceWrapper(ValueWrapper):
     def py__stop_iteration_returns(self):

jedi/inference/value/instance.py

@@ -288,6 +288,11 @@ def py__get__(self, instance, class_value):
         """
         # Arguments in __get__ descriptors are obj, class.
         # `method` is the new parent of the array, don't know if that's good.
+        for cls in self.class_value.py__mro__():
+            result = cls.py__get__on_class(self, instance, class_value)
+            if result is not NotImplemented:
+                return result
+
         names = self.get_function_slot_names(u'__get__')
         if names:
             if instance is None:

jedi/inference/value/klass.py

@@ -114,8 +114,6 @@ def _access_possible(self, name):
             if expr_stmt is not None and expr_stmt.type == 'expr_stmt':
                 annassign = expr_stmt.children[1]
                 if annassign.type == 'annassign':
-                    # TODO this is not proper matching
-
                     # If there is an =, the variable is obviously also
                     # defined on the class.
                     if 'ClassVar' not in annassign.children[1].get_code() \
@@ -138,7 +136,7 @@ def is_class(self):
     def is_class_mixin(self):
         return True
 
-    def py__call__(self, arguments=None):
+    def py__call__(self, arguments):
         from jedi.inference.value import TreeInstance
 
         from jedi.inference.gradual.typing import TypedDict
@@ -195,15 +193,15 @@ def get_filters(self, origin_scope=None, is_instance=False,
             metaclasses = self.get_metaclasses()
             if metaclasses:
                 for f in self.get_metaclass_filters(metaclasses, is_instance):
-                    yield f
+                    yield f  # Python 2..
 
         for cls in self.py__mro__():
             if cls.is_compiled():
                 for filter in cls.get_filters(is_instance=is_instance):
                     yield filter
             else:
                 yield ClassFilter(
-                    self, node_context=cls.as_context(),
+                    cls, node_context=self.as_context(),
                     origin_scope=origin_scope,
                     is_instance=is_instance
                 )

jedi/plugins/django.py

@@ -2,12 +2,15 @@
 Module is used to infer Django model fields.
 """
 from jedi import debug
-from jedi.inference.base_value import ValueSet, iterator_to_value_set
-from jedi.inference.filters import ParserTreeFilter, DictFilter
+from jedi.inference.base_value import ValueSet, iterator_to_value_set, ValueWrapper
+from jedi.inference.filters import DictFilter, AttributeOverwrite, publish_method
 from jedi.inference.names import NameWrapper
+from jedi.inference.compiled.value import EmptyCompiledName
 from jedi.inference.value.instance import TreeInstance
+from jedi.inference.value.klass import ClassMixin
 from jedi.inference.gradual.base import GenericClass
 from jedi.inference.gradual.generics import TupleGenericManager
+from jedi.inference.arguments import repack_with_argument_clinic
 
 
 mapping = {
@@ -124,36 +127,6 @@ def _create_manager_for(cls, manager_cls='BaseManager'):
 
 
 def _new_dict_filter(cls, is_instance):
-    def get_manager_name(filters):
-        for f in filters:
-            names = f.get('objects')
-            if not names:
-                continue
-
-            # Found a match. Either the model has a custom manager, or we're
-            # now in django.db.models.Model. If the latter we need to use
-            # `_create_manager_for` because the manager we get from the
-            # stubs doesn't work right.
-
-            name = names[0]  # The first name should be good enough.
-
-            parent = name.get_defining_qualified_value()
-            if parent.py__name__() == 'Model':
-
-                django_models_model, = cls.inference_state.import_module(
-                    ('django', 'db', 'models', 'base'),
-                ).py__getattribute__('Model')
-                if django_models_model == parent:
-                    # Don't want to use the value from the Django stubs, but
-                    # we have found the point where they'd take precedence.
-                    break
-
-            return name
-
-        manager = _create_manager_for(cls)
-        if manager:
-            return manager.name
-
     filters = list(cls.get_filters(
         is_instance=is_instance,
         include_metaclasses=False,
@@ -164,10 +137,14 @@ def get_manager_name(filters):
         for filter_ in reversed(filters)
         for name in filter_.values()
     }
-
-    manager_name = get_manager_name(filters)
-    if manager_name:
-        dct['objects'] = manager_name
+    if is_instance:
+        # Replace the objects with a name that amounts to nothing when accessed
+        # in an instance. This is not perfect and still completes "objects" in
+        # that case, but it at least not inferes stuff like `.objects.filter`.
+        # It would be nicer to do that in a better way, so that it also doesn't
+        # show up in completions, but it's probably just not worth doing that
+        # for the extra amount of work.
+        dct['objects'] = EmptyCompiledName(cls.inference_state, 'objects')
 
     return DictFilter(dct)
 
@@ -181,3 +158,32 @@ def wrapper(cls, metaclasses, is_instance):
 
         return func(cls, metaclasses, is_instance)
     return wrapper
+
+
+class ManagerWrapper(ValueWrapper):
+    def py__getitem__(self, index_value_set, contextualized_node):
+        return ValueSet(
+            GenericManagerWrapper(generic)
+            for generic in self._wrapped_value.py__getitem__(
+                index_value_set, contextualized_node)
+        )
+
+
+class GenericManagerWrapper(AttributeOverwrite, ClassMixin):
+    def py__get__on_class(self, calling_instance, instance, class_value):
+        return calling_instance.class_value.with_generics(
+            (ValueSet({class_value}),)
+        ).py__call__(calling_instance._arguments)
+
+    def with_generics(self, generics_tuple):
+        return self._wrapped_value.with_generics(generics_tuple)
+
+
+def tree_name_to_values(func):
+    def wrapper(inference_state, context, tree_name):
+        result = func(inference_state, context, tree_name)
+        if tree_name.value == 'BaseManager' and context.is_module() \
+                and context.py__name__() == 'django.db.models.manager':
+            return ValueSet(ManagerWrapper(r) for r in result)
+        return result
+    return wrapper

test/completion/django.py

@@ -162,26 +162,36 @@ def method(self):
 # Queries
 # -----------------
 
-#? models.query.QuerySet.filter
+#? ['objects']
+model_instance.object
+#?
+model_instance.objects
+#?
 model_instance.objects.filter
+#? models.query.QuerySet.filter
+BusinessModel.objects.filter
 #? BusinessModel() None
-model_instance.objects.filter().first()
+BusinessModel.objects.filter().first()
 #? str()
-model_instance.objects.get().char_field
+BusinessModel.objects.get().char_field
 #? int()
-model_instance.objects.update(x='')
+BusinessModel.objects.update(x='')
 #? BusinessModel()
-model_instance.objects.create()
+BusinessModel.objects.create()
 
 # -----------------
 # Custom object manager
 # -----------------
 
 #? TagManager()
 Tag.objects
+#? Tag() None
+Tag.objects.filter().first()
 
 #? TagManager()
 Tag.custom_objects
+#? Tag() None
+Tag.custom_objects.filter().first()
 
 # -----------------
 # Inheritance
@@ -199,14 +209,27 @@ class Inherited(BusinessModel):
 #? float()
 inherited.new_field
 
+#?
+Inherited.category_fk2.category_name
 #? str()
 inherited.category_fk2.category_name
 #? str()
-inherited.objects.get().char_field
+Inherited.objects.get().char_field
 #? int()
-inherited.objects.get().text_field
+Inherited.objects.get().text_field
 #? float()
-inherited.objects.get().new_field
+Inherited.objects.get().new_field
+
+# -----------------
+# Model methods
+# -----------------
+
+#? ['from_db']
+Inherited.from_db
+#? ['validate_unique']
+Inherited.validate_uniqu
+#? ['validate_unique']
+Inherited().validate_unique
 
 # -----------------
 # Django Auth
@@ -222,8 +245,8 @@ class Inherited(BusinessModel):
 # -----------------
 
 #?
-model_instance.objects.values_list('char_field')[0]
+BusinessModel.objects.values_list('char_field')[0]
 #? dict()
-model_instance.objects.values('char_field')[0]
+BusinessModel.objects.values('char_field')[0]
 #?
-model_instance.objects.values('char_field')[0]['char_field']
+BusinessModel.objects.values('char_field')[0]['char_field']