Files
django-stubs/mypy_django_plugin/transformers/models.py
Sigurd Ljødal 830d74b493 Add support for inline from_queryset in model classes (#1045)
* Add support for inline from_queryset in model classes

This adds support for calling <Manager>.from_queryset(<QuerySet>)()
inline in models, for example like this:

    class MyModel(models.Model):
        objects = MyManager.from_queryset(MyQuerySet)()

This is done by inspecting the class body in the transform_class_hook

* Fix missing methods on copied manager

* Add test and other minor tweaks

* Always create manager at module level

When the manager is added at the class level, which happened when it was
created inline in the model body, it's not possible to retrieve the
manager again based on fullname. That lead to problems with inheritance
and the default manager.
2022-07-13 10:04:44 +03:00

639 lines
30 KiB
Python

from typing import Dict, List, Optional, Type, Union, cast
from django.db.models import Manager, Model
from django.db.models.fields import DateField, DateTimeField, Field
from django.db.models.fields.related import ForeignKey
from django.db.models.fields.reverse_related import ManyToManyRel, ManyToOneRel, OneToOneRel
from mypy.checker import TypeChecker
from mypy.nodes import ARG_STAR2, Argument, AssignmentStmt, CallExpr, Context, FuncDef, NameExpr, TypeInfo, Var
from mypy.plugin import AnalyzeTypeContext, AttributeContext, CheckerPluginInterface, ClassDefContext
from mypy.plugins import common
from mypy.semanal import SemanticAnalyzer
from mypy.types import AnyType, Instance
from mypy.types import Type as MypyType
from mypy.types import TypedDictType, TypeOfAny
from mypy_django_plugin.django.context import DjangoContext
from mypy_django_plugin.errorcodes import MANAGER_MISSING
from mypy_django_plugin.lib import fullnames, helpers
from mypy_django_plugin.lib.fullnames import ANNOTATIONS_FULLNAME, ANY_ATTR_ALLOWED_CLASS_FULLNAME, MODEL_CLASS_FULLNAME
from mypy_django_plugin.transformers import fields
from mypy_django_plugin.transformers.fields import get_field_descriptor_types
from mypy_django_plugin.transformers.managers import create_manager_info_from_from_queryset_call
class ModelClassInitializer:
api: SemanticAnalyzer
def __init__(self, ctx: ClassDefContext, django_context: DjangoContext):
self.api = cast(SemanticAnalyzer, ctx.api)
self.model_classdef = ctx.cls
self.django_context = django_context
self.ctx = ctx
def lookup_typeinfo(self, fullname: str) -> Optional[TypeInfo]:
return helpers.lookup_fully_qualified_typeinfo(self.api, fullname)
def lookup_typeinfo_or_incomplete_defn_error(self, fullname: str) -> TypeInfo:
info = self.lookup_typeinfo(fullname)
if info is None:
raise helpers.IncompleteDefnException(f"No {fullname!r} found")
return info
def lookup_class_typeinfo_or_incomplete_defn_error(self, klass: type) -> TypeInfo:
fullname = helpers.get_class_fullname(klass)
field_info = self.lookup_typeinfo_or_incomplete_defn_error(fullname)
return field_info
def create_new_var(self, name: str, typ: MypyType) -> Var:
# type=: type of the variable itself
var = Var(name=name, type=typ)
# var.info: type of the object variable is bound to
var.info = self.model_classdef.info
var._fullname = self.model_classdef.info.fullname + "." + name
var.is_initialized_in_class = True
var.is_inferred = True
return var
def add_new_node_to_model_class(self, name: str, typ: MypyType, no_serialize: bool = False) -> None:
helpers.add_new_sym_for_info(self.model_classdef.info, name=name, sym_type=typ, no_serialize=no_serialize)
def add_new_class_for_current_module(self, name: str, bases: List[Instance]) -> TypeInfo:
current_module = self.api.modules[self.model_classdef.info.module_name]
new_class_info = helpers.add_new_class_for_module(current_module, name=name, bases=bases)
return new_class_info
def run(self) -> None:
model_cls = self.django_context.get_model_class_by_fullname(self.model_classdef.fullname)
if model_cls is None:
return
self.run_with_model_cls(model_cls)
def get_generated_manager_mappings(self, base_manager_fullname: str) -> Dict[str, str]:
base_manager_info = self.lookup_typeinfo(base_manager_fullname)
if base_manager_info is None or "from_queryset_managers" not in base_manager_info.metadata:
return {}
return base_manager_info.metadata["from_queryset_managers"]
def get_generated_manager_info(self, manager_fullname: str, base_manager_fullname: str) -> Optional[TypeInfo]:
generated_managers = self.get_generated_manager_mappings(base_manager_fullname)
real_manager_fullname = generated_managers.get(manager_fullname)
if real_manager_fullname:
return self.lookup_typeinfo(real_manager_fullname)
# Not a generated manager
return None
def run_with_model_cls(self, model_cls):
raise NotImplementedError("Implement this in subclasses")
class InjectAnyAsBaseForNestedMeta(ModelClassInitializer):
"""
Replaces
class MyModel(models.Model):
class Meta:
pass
with
class MyModel(models.Model):
class Meta(Any):
pass
to get around incompatible Meta inner classes for different models.
"""
def run(self) -> None:
meta_node = helpers.get_nested_meta_node_for_current_class(self.model_classdef.info)
if meta_node is None:
return None
meta_node.fallback_to_any = True
class AddDefaultPrimaryKey(ModelClassInitializer):
def run_with_model_cls(self, model_cls: Type[Model]) -> None:
auto_field = model_cls._meta.auto_field
if auto_field:
self.create_autofield(
auto_field=auto_field,
dest_name=auto_field.attname,
existing_field=not self.model_classdef.info.has_readable_member(auto_field.attname),
)
def create_autofield(
self,
auto_field: Field,
dest_name: str,
existing_field: bool,
) -> None:
if existing_field:
auto_field_fullname = helpers.get_class_fullname(auto_field.__class__)
auto_field_info = self.lookup_typeinfo_or_incomplete_defn_error(auto_field_fullname)
set_type, get_type = fields.get_field_descriptor_types(
auto_field_info,
is_set_nullable=True,
is_get_nullable=False,
)
self.add_new_node_to_model_class(dest_name, Instance(auto_field_info, [set_type, get_type]))
class AddPrimaryKeyAlias(AddDefaultPrimaryKey):
def run_with_model_cls(self, model_cls: Type[Model]) -> None:
# We also need to override existing `pk` definition from `stubs`:
auto_field = model_cls._meta.pk
if auto_field:
self.create_autofield(
auto_field=auto_field,
dest_name="pk",
existing_field=self.model_classdef.info.has_readable_member(auto_field.name),
)
class AddRelatedModelsId(ModelClassInitializer):
def run_with_model_cls(self, model_cls: Type[Model]) -> None:
for field in model_cls._meta.get_fields():
if isinstance(field, ForeignKey):
related_model_cls = self.django_context.get_field_related_model_cls(field)
if related_model_cls is None:
error_context: Context = self.ctx.cls
field_sym = self.ctx.cls.info.get(field.name)
if field_sym is not None and field_sym.node is not None:
error_context = field_sym.node
self.api.fail(
f"Cannot find model {field.related_model!r} referenced in field {field.name!r}",
ctx=error_context,
)
self.add_new_node_to_model_class(field.attname, AnyType(TypeOfAny.explicit))
continue
if related_model_cls._meta.abstract:
continue
rel_primary_key_field = self.django_context.get_primary_key_field(related_model_cls)
try:
field_info = self.lookup_class_typeinfo_or_incomplete_defn_error(rel_primary_key_field.__class__)
except helpers.IncompleteDefnException as exc:
if not self.api.final_iteration:
raise exc
else:
continue
is_nullable = self.django_context.get_field_nullability(field, None)
set_type, get_type = get_field_descriptor_types(
field_info, is_set_nullable=is_nullable, is_get_nullable=is_nullable
)
self.add_new_node_to_model_class(field.attname, Instance(field_info, [set_type, get_type]))
class AddManagers(ModelClassInitializer):
def has_any_parametrized_manager_as_base(self, info: TypeInfo) -> bool:
for base in helpers.iter_bases(info):
if self.is_any_parametrized_manager(base):
return True
return False
def is_any_parametrized_manager(self, typ: Instance) -> bool:
return typ.type.fullname in fullnames.MANAGER_CLASSES and isinstance(typ.args[0], AnyType)
def create_new_model_parametrized_manager(self, name: str, base_manager_info: TypeInfo) -> Instance:
bases = []
for original_base in base_manager_info.bases:
if self.is_any_parametrized_manager(original_base):
original_base = helpers.reparametrize_instance(original_base, [Instance(self.model_classdef.info, [])])
bases.append(original_base)
# TODO: This adds the manager to the module, even if we end up
# deferring. That can be avoided by not adding it to the module first,
# but rather waiting until we know we won't defer
new_manager_info = self.add_new_class_for_current_module(name, bases)
# copy fields to a new manager
new_cls_def_context = ClassDefContext(cls=new_manager_info.defn, reason=self.ctx.reason, api=self.api)
custom_manager_type = Instance(new_manager_info, [Instance(self.model_classdef.info, [])])
for name, sym in base_manager_info.names.items():
# replace self type with new class, if copying method
if isinstance(sym.node, FuncDef):
copied_method = helpers.copy_method_to_another_class(
new_cls_def_context,
self_type=custom_manager_type,
new_method_name=name,
method_node=sym.node,
original_module_name=base_manager_info.module_name,
)
if not copied_method and not self.api.final_iteration:
raise helpers.IncompleteDefnException()
continue
new_sym = sym.copy()
if isinstance(new_sym.node, Var):
new_var = Var(name, type=sym.type)
new_var.info = new_manager_info
new_var._fullname = new_manager_info.fullname + "." + name
new_sym.node = new_var
new_manager_info.names[name] = new_sym
return custom_manager_type
def run_with_model_cls(self, model_cls: Type[Model]) -> None:
manager_info: Optional[TypeInfo]
incomplete_manager_defs = set()
for manager_name, manager in model_cls._meta.managers_map.items():
# If the manager is already typed do nothing
manager_node = self.model_classdef.info.names.get(manager_name, None)
if manager_node and manager_node.type is not None:
continue
manager_class_name = manager.__class__.__name__
manager_fullname = helpers.get_class_fullname(manager.__class__)
manager_info = self.lookup_typeinfo(manager_fullname)
if manager_info is None:
manager_info = self.create_manager_from_from_queryset(manager_name)
if manager_info is None:
manager_info = self.get_dynamic_manager(manager_fullname, manager)
if manager_info is None:
incomplete_manager_defs.add(manager_name)
continue
is_dynamically_generated = manager_info.metadata.get("django", {}).get("from_queryset_manager") is not None
if manager_name not in self.model_classdef.info.names or is_dynamically_generated:
manager_type = Instance(manager_info, [Instance(self.model_classdef.info, [])])
self.add_new_node_to_model_class(manager_name, manager_type)
elif self.has_any_parametrized_manager_as_base(manager_info):
# Ending up here could for instance be due to having a custom _Manager_
# that is not built from a custom QuerySet. Another example is a
# related manager.
custom_model_manager_name = manager.model.__name__ + "_" + manager_class_name
try:
manager_type = self.create_new_model_parametrized_manager(
custom_model_manager_name, base_manager_info=manager_info
)
except helpers.IncompleteDefnException:
continue
self.add_new_node_to_model_class(manager_name, manager_type)
if incomplete_manager_defs:
if not self.api.final_iteration:
# Unless we're on the final round, see if another round could
# figure out all manager types
raise helpers.IncompleteDefnException()
for manager_name in incomplete_manager_defs:
# We act graceful and set the type as the bare minimum we know of
# (Django's default) before finishing. And emit an error, to allow for
# ignoring a more specialised manager not being resolved while still
# setting _some_ type
django_manager_info = self.lookup_typeinfo(fullnames.MANAGER_CLASS_FULLNAME)
assert (
django_manager_info is not None
), f"Type info for Django's {fullnames.MANAGER_CLASS_FULLNAME} missing"
self.add_new_node_to_model_class(
manager_name, Instance(django_manager_info, [Instance(self.model_classdef.info, [])])
)
# Find expression for e.g. `objects = SomeManager()`
manager_expr = self.get_manager_expression(manager_name)
manager_fullname = f"{self.model_classdef.fullname}.{manager_name}"
self.api.fail(
f'Could not resolve manager type for "{manager_fullname}"',
manager_expr if manager_expr else self.ctx.cls,
code=MANAGER_MISSING,
)
def get_manager_expression(self, name: str) -> Optional[AssignmentStmt]:
# TODO: What happens if the manager is defined multiple times?
for expr in self.ctx.cls.defs.body:
if (
isinstance(expr, AssignmentStmt)
and isinstance(expr.lvalues[0], NameExpr)
and expr.lvalues[0].name == name
):
return expr
return None
def get_dynamic_manager(self, fullname: str, manager: Manager) -> Optional[TypeInfo]:
"""
Try to get a dynamically defined manager
"""
# Check if manager is a generated (dynamic class) manager
base_manager_fullname = helpers.get_class_fullname(manager.__class__.__bases__[0])
generated_managers = self.get_generated_manager_mappings(base_manager_fullname)
generated_manager_name: Optional[str] = generated_managers.get(fullname, None)
if generated_manager_name is None:
return None
return self.lookup_typeinfo(generated_manager_name)
def create_manager_from_from_queryset(self, name: str) -> Optional[TypeInfo]:
"""
Try to create a manager from a .from_queryset call:
class MyModel(models.Model):
objects = MyManager.from_queryset(MyQuerySet)()
"""
assign_statement = self.get_manager_expression(name)
if assign_statement is None:
return None
expr = assign_statement.rvalue
if not isinstance(expr, CallExpr) or not isinstance(expr.callee, CallExpr):
return None
return create_manager_info_from_from_queryset_call(self.api, expr.callee)
class AddDefaultManagerAttribute(ModelClassInitializer):
def run_with_model_cls(self, model_cls: Type[Model]) -> None:
if "_default_manager" in self.model_classdef.info.names:
return None
default_manager_cls = model_cls._meta.default_manager.__class__
default_manager_fullname = helpers.get_class_fullname(default_manager_cls)
try:
default_manager_info = self.lookup_typeinfo_or_incomplete_defn_error(default_manager_fullname)
except helpers.IncompleteDefnException as exc:
# Check if default manager could be a generated manager
base_manager_fullname = helpers.get_class_fullname(default_manager_cls.__bases__[0])
generated_manager_info = self.get_generated_manager_info(default_manager_fullname, base_manager_fullname)
if generated_manager_info is None:
# Manager doesn't appear to be generated. Unless we're on the final round,
# see if another round could help figuring out the default manager type
if not self.api.final_iteration:
raise exc
else:
return None
default_manager_info = generated_manager_info
default_manager = Instance(default_manager_info, [Instance(self.model_classdef.info, [])])
self.add_new_node_to_model_class("_default_manager", default_manager)
class AddRelatedManagers(ModelClassInitializer):
def get_reverse_manager_info(self, model_info: TypeInfo, derived_from: str) -> Optional[TypeInfo]:
manager_fullname = helpers.get_django_metadata(model_info).get("reverse_managers", {}).get(derived_from)
if not manager_fullname:
return None
symbol = self.api.lookup_fully_qualified_or_none(manager_fullname)
if symbol is None or not isinstance(symbol.node, TypeInfo):
return None
return symbol.node
def set_reverse_manager_info(self, model_info: TypeInfo, derived_from: str, fullname: str) -> None:
helpers.get_django_metadata(model_info).setdefault("reverse_managers", {})[derived_from] = fullname
def run_with_model_cls(self, model_cls: Type[Model]) -> None:
# add related managers
for relation in self.django_context.get_model_relations(model_cls):
attname = relation.get_accessor_name()
if attname is None or attname in self.model_classdef.info.names:
# No reverse accessor or already declared. Note that this would also leave any
# explicitly declared(i.e. non-inferred) reverse accessors alone
continue
related_model_cls = self.django_context.get_field_related_model_cls(relation)
if related_model_cls is None:
continue
try:
related_model_info = self.lookup_class_typeinfo_or_incomplete_defn_error(related_model_cls)
except helpers.IncompleteDefnException as exc:
if not self.api.final_iteration:
raise exc
else:
continue
if isinstance(relation, OneToOneRel):
self.add_new_node_to_model_class(attname, Instance(related_model_info, []))
continue
if isinstance(relation, (ManyToOneRel, ManyToManyRel)):
related_manager_info = None
try:
related_manager_info = self.lookup_typeinfo_or_incomplete_defn_error(
fullnames.RELATED_MANAGER_CLASS
) # noqa: E501
default_manager = related_model_info.names.get("_default_manager")
if not default_manager:
raise helpers.IncompleteDefnException()
except helpers.IncompleteDefnException as exc:
if not self.api.final_iteration:
raise exc
else:
if related_manager_info:
"""
If a django model has a Manager class that cannot be
resolved statically (if it is generated in a way
where we cannot import it, like `objects = my_manager_factory()`),
we fallback to the default related manager, so you
at least get a base level of working type checking.
See https://github.com/typeddjango/django-stubs/pull/993
for more information on when this error can occur.
"""
self.add_new_node_to_model_class(
attname, Instance(related_manager_info, [Instance(related_model_info, [])])
)
related_model_fullname = related_model_cls.__module__ + "." + related_model_cls.__name__
self.ctx.api.fail(
f"Couldn't resolve related manager for relation {relation.name!r} (from {related_model_fullname}.{relation.field}).",
self.ctx.cls,
code=MANAGER_MISSING,
)
continue
# Check if the related model has a related manager subclassed from the default manager
# TODO: Support other reverse managers than `_default_manager`
default_reverse_manager_info = self.get_reverse_manager_info(
model_info=related_model_info, derived_from="_default_manager"
)
if default_reverse_manager_info:
self.add_new_node_to_model_class(
attname, Instance(default_reverse_manager_info, []), no_serialize=True
)
continue
# The reverse manager we're looking for doesn't exist. So we create it.
# The (default) reverse manager type is built from a RelatedManager and the default manager on the related model
parametrized_related_manager_type = Instance(related_manager_info, [Instance(related_model_info, [])])
default_manager_type = default_manager.type
assert default_manager_type is not None
assert isinstance(default_manager_type, Instance)
# When the default manager isn't custom there's no need to create a new type
# as `RelatedManager` has `models.Manager` as base
if default_manager_type.type.fullname == fullnames.MANAGER_CLASS_FULLNAME:
self.add_new_node_to_model_class(attname, parametrized_related_manager_type)
continue
# The reverse manager is based on the related model's manager, so it makes most sense to add the new
# related manager in that module
new_related_manager_info = helpers.add_new_class_for_module(
module=self.api.modules[related_model_info.module_name],
name=f"{related_model_cls.__name__}_RelatedManager",
bases=[parametrized_related_manager_type, default_manager_type],
no_serialize=True,
)
new_related_manager_info.metadata["django"] = {"related_manager_to_model": related_model_info.fullname}
# Stash the new reverse manager type fullname on the related model, so we don't duplicate
# or have to create it again for other reverse relations
self.set_reverse_manager_info(
related_model_info,
derived_from="_default_manager",
fullname=new_related_manager_info.fullname,
)
self.add_new_node_to_model_class(attname, Instance(new_related_manager_info, []), no_serialize=True)
class AddExtraFieldMethods(ModelClassInitializer):
def run_with_model_cls(self, model_cls: Type[Model]) -> None:
# get_FOO_display for choices
for field in self.django_context.get_model_fields(model_cls):
if field.choices:
info = self.lookup_typeinfo_or_incomplete_defn_error("builtins.str")
return_type = Instance(info, [])
common.add_method(self.ctx, name=f"get_{field.attname}_display", args=[], return_type=return_type)
# get_next_by, get_previous_by for Date, DateTime
for field in self.django_context.get_model_fields(model_cls):
if isinstance(field, (DateField, DateTimeField)) and not field.null:
return_type = Instance(self.model_classdef.info, [])
common.add_method(
self.ctx,
name=f"get_next_by_{field.attname}",
args=[
Argument(
Var("kwargs", AnyType(TypeOfAny.explicit)),
AnyType(TypeOfAny.explicit),
initializer=None,
kind=ARG_STAR2,
)
],
return_type=return_type,
)
common.add_method(
self.ctx,
name=f"get_previous_by_{field.attname}",
args=[
Argument(
Var("kwargs", AnyType(TypeOfAny.explicit)),
AnyType(TypeOfAny.explicit),
initializer=None,
kind=ARG_STAR2,
)
],
return_type=return_type,
)
class AddMetaOptionsAttribute(ModelClassInitializer):
def run_with_model_cls(self, model_cls: Type[Model]) -> None:
if "_meta" not in self.model_classdef.info.names:
options_info = self.lookup_typeinfo_or_incomplete_defn_error(fullnames.OPTIONS_CLASS_FULLNAME)
self.add_new_node_to_model_class("_meta", Instance(options_info, [Instance(self.model_classdef.info, [])]))
def process_model_class(ctx: ClassDefContext, django_context: DjangoContext) -> None:
initializers = [
InjectAnyAsBaseForNestedMeta,
AddDefaultPrimaryKey,
AddPrimaryKeyAlias,
AddRelatedModelsId,
AddManagers,
AddDefaultManagerAttribute,
AddRelatedManagers,
AddExtraFieldMethods,
AddMetaOptionsAttribute,
]
for initializer_cls in initializers:
try:
initializer_cls(ctx, django_context).run()
except helpers.IncompleteDefnException:
if not ctx.api.final_iteration:
ctx.api.defer()
def set_auth_user_model_boolean_fields(ctx: AttributeContext, django_context: DjangoContext) -> MypyType:
boolinfo = helpers.lookup_class_typeinfo(helpers.get_typechecker_api(ctx), bool)
assert boolinfo is not None
return Instance(boolinfo, [])
def handle_annotated_type(ctx: AnalyzeTypeContext, django_context: DjangoContext) -> MypyType:
args = ctx.type.args
type_arg = ctx.api.analyze_type(args[0])
api = cast(SemanticAnalyzer, ctx.api.api) # type: ignore
if not isinstance(type_arg, Instance) or not type_arg.type.has_base(MODEL_CLASS_FULLNAME):
return type_arg
fields_dict = None
if len(args) > 1:
second_arg_type = ctx.api.analyze_type(args[1])
if isinstance(second_arg_type, TypedDictType):
fields_dict = second_arg_type
elif isinstance(second_arg_type, Instance) and second_arg_type.type.fullname == ANNOTATIONS_FULLNAME:
annotations_type_arg = second_arg_type.args[0]
if isinstance(annotations_type_arg, TypedDictType):
fields_dict = annotations_type_arg
elif not isinstance(annotations_type_arg, AnyType):
ctx.api.fail("Only TypedDicts are supported as type arguments to Annotations", ctx.context)
return get_or_create_annotated_type(api, type_arg, fields_dict=fields_dict)
def get_or_create_annotated_type(
api: Union[SemanticAnalyzer, CheckerPluginInterface], model_type: Instance, fields_dict: Optional[TypedDictType]
) -> Instance:
"""
Get or create the type for a model for which you getting/setting any attr is allowed.
The generated type is an subclass of the model and django._AnyAttrAllowed.
The generated type is placed in the django_stubs_ext module, with the name WithAnnotations[ModelName].
If the user wanted to annotate their code using this type, then this is the annotation they would use.
This is a bit of a hack to make a pretty type for error messages and which would make sense for users.
"""
model_module_name = "django_stubs_ext"
if helpers.is_annotated_model_fullname(model_type.type.fullname):
# If it's already a generated class, we want to use the original model as a base
model_type = model_type.type.bases[0]
if fields_dict is not None:
type_name = f"WithAnnotations[{model_type.type.fullname.replace('.', '__')}, {fields_dict}]"
else:
type_name = f"WithAnnotations[{model_type.type.fullname.replace('.', '__')}]"
annotated_typeinfo = helpers.lookup_fully_qualified_typeinfo(
cast(TypeChecker, api), model_module_name + "." + type_name
)
if annotated_typeinfo is None:
model_module_file = api.modules[model_module_name] # type: ignore
if isinstance(api, SemanticAnalyzer):
annotated_model_type = api.named_type_or_none(ANY_ATTR_ALLOWED_CLASS_FULLNAME, [])
assert annotated_model_type is not None
else:
annotated_model_type = api.named_generic_type(ANY_ATTR_ALLOWED_CLASS_FULLNAME, [])
annotated_typeinfo = helpers.add_new_class_for_module(
model_module_file,
type_name,
bases=[model_type] if fields_dict is not None else [model_type, annotated_model_type],
fields=fields_dict.items if fields_dict is not None else None,
no_serialize=True,
)
if fields_dict is not None:
# To allow structural subtyping, make it a Protocol
annotated_typeinfo.is_protocol = True
# Save for later to easily find which field types were annotated
annotated_typeinfo.metadata["annotated_field_types"] = fields_dict.items
annotated_type = Instance(annotated_typeinfo, [])
return annotated_type