Files
django-stubs/mypy_django_plugin/transformers/models.py
Konstantin Alekseev cbc7159995 Support mypy 0.750
2019-11-30 13:39:28 +03:00

269 lines
13 KiB
Python

from collections import OrderedDict
from typing import Type
from django.db.models.base import Model
from django.db.models.fields import DateField, DateTimeField
from django.db.models.fields.related import ForeignKey
from django.db.models.fields.reverse_related import (
ManyToManyRel, ManyToOneRel, OneToOneRel,
)
from mypy.nodes import ARG_STAR2, Argument, Context, TypeInfo, Var
from mypy.plugin import ClassDefContext
from mypy.plugins import common
from mypy.types import AnyType, Instance
from mypy.types import Type as MypyType
from mypy.types import TypeOfAny
from mypy_django_plugin.django.context import DjangoContext
from mypy_django_plugin.lib import fullnames, helpers
from mypy_django_plugin.transformers import fields
from mypy_django_plugin.transformers.fields import get_field_descriptor_types
class ModelClassInitializer:
def __init__(self, ctx: ClassDefContext, django_context: DjangoContext):
self.api = ctx.api
self.model_classdef = ctx.cls
self.django_context = django_context
self.ctx = ctx
def lookup_typeinfo_or_incomplete_defn_error(self, fullname: str) -> TypeInfo:
sym = self.api.lookup_fully_qualified_or_none(fullname)
if sym is None or not isinstance(sym.node, TypeInfo):
raise helpers.IncompleteDefnException(f'No {fullname!r} found')
return sym.node
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) -> None:
helpers.add_new_sym_for_info(self.model_classdef.info,
name=name,
sym_type=typ)
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 run_with_model_cls(self, model_cls):
pass
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 and not self.model_classdef.info.has_readable_member(auto_field.attname):
# autogenerated 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_nullable=False)
self.add_new_node_to_model_class(auto_field.attname, Instance(auto_field_info,
[set_type, get_type]))
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} '
f'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)
field_info = self.lookup_class_typeinfo_or_incomplete_defn_error(rel_primary_key_field.__class__)
is_nullable = self.django_context.get_field_nullability(field, None)
set_type, get_type = get_field_descriptor_types(field_info, is_nullable)
self.add_new_node_to_model_class(field.attname,
Instance(field_info, [set_type, get_type]))
class AddManagers(ModelClassInitializer):
def _is_manager_any(self, typ: Instance) -> bool:
return typ.type.fullname == fullnames.MANAGER_CLASS_FULLNAME and type(typ.args[0]) == AnyType
def run_with_model_cls(self, model_cls: Type[Model]) -> None:
for manager_name, manager in model_cls._meta.managers_map.items():
manager_fullname = helpers.get_class_fullname(manager.__class__)
manager_info = self.lookup_typeinfo_or_incomplete_defn_error(manager_fullname)
if manager_name not in self.model_classdef.info.names:
manager_type = Instance(manager_info, [Instance(self.model_classdef.info, [])])
self.add_new_node_to_model_class(manager_name, manager_type)
else:
# creates new MODELNAME_MANAGERCLASSNAME class that represents manager parametrized with current model
has_manager_any_base = any(self._is_manager_any(base) for base in manager_info.bases)
if has_manager_any_base:
custom_model_manager_name = manager.model.__name__ + '_' + manager.__class__.__name__
bases = []
for original_base in manager_info.bases:
if self._is_manager_any(original_base):
if original_base.type is None:
raise helpers.IncompleteDefnException()
original_base = helpers.reparametrize_instance(original_base,
[Instance(self.model_classdef.info, [])])
bases.append(original_base)
current_module = self.api.modules[self.model_classdef.info.module_name]
custom_manager_info = helpers.add_new_class_for_module(current_module,
custom_model_manager_name,
bases=bases,
fields=OrderedDict())
# copy fields to a new manager
for name, sym in manager_info.names.items():
new_sym = sym.copy()
if isinstance(new_sym.node, Var):
new_var = Var(name, type=sym.type)
new_var.info = custom_manager_info
new_var._fullname = custom_manager_info.fullname + '.' + name
new_sym.node = new_var
custom_manager_info.names[name] = new_sym
custom_manager_type = Instance(custom_manager_info, [Instance(self.model_classdef.info, [])])
self.add_new_node_to_model_class(manager_name, custom_manager_type)
class AddDefaultManagerAttribute(ModelClassInitializer):
def run_with_model_cls(self, model_cls: Type[Model]) -> None:
# add _default_manager
if '_default_manager' not in self.model_classdef.info.names:
default_manager_fullname = helpers.get_class_fullname(model_cls._meta.default_manager.__class__)
default_manager_info = self.lookup_typeinfo_or_incomplete_defn_error(default_manager_fullname)
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 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:
# no reverse accessor
continue
related_model_cls = self.django_context.get_field_related_model_cls(relation)
if related_model_cls is None:
continue
related_model_info = self.lookup_class_typeinfo_or_incomplete_defn_error(related_model_cls)
if isinstance(relation, OneToOneRel):
self.add_new_node_to_model_class(attname, Instance(related_model_info, []))
continue
if isinstance(relation, (ManyToOneRel, ManyToManyRel)):
manager_info = self.lookup_typeinfo_or_incomplete_defn_error(fullnames.RELATED_MANAGER_CLASS_FULLNAME)
self.add_new_node_to_model_class(attname,
Instance(manager_info, [Instance(related_model_info, [])]))
continue
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='get_{}_display'.format(field.attname),
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='get_next_by_{}'.format(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='get_previous_by_{}'.format(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,
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()