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django-stubs/mypy_django_plugin/plugins/base.py

78 lines
3.3 KiB
Python

from typing import Callable, Optional
from mypy.nodes import AssignmentStmt, CallExpr, RefExpr, StrExpr
from mypy.plugin import Plugin, ClassDefContext
from mypy_django_plugin.helpers import get_app_model
from mypy_django_plugin.model_classes import DjangoModelsRegistry
# fields which real type is inside to= expression
REFERENCING_DB_FIELDS = {
'django.db.models.fields.related.ForeignKey',
'django.db.models.fields.related.OneToOneField'
}
def save_referred_to_model_in_metadata(rvalue: CallExpr) -> None:
to_arg_value = rvalue.args[rvalue.arg_names.index('to')]
if isinstance(to_arg_value, StrExpr):
referred_model_fullname = get_app_model(to_arg_value.value)
else:
referred_model_fullname = to_arg_value.fullname
rvalue.callee.node.metadata['base'] = referred_model_fullname
class CollectModelsInformation(object):
def __init__(self, model_registry: DjangoModelsRegistry):
self.model_registry = model_registry
def __call__(self, model_definition: ClassDefContext) -> None:
self.model_registry.base_models.add(model_definition.cls.fullname)
for member in model_definition.cls.defs.body:
if isinstance(member, AssignmentStmt):
if len(member.lvalues) > 1:
return None
arg_name = member.lvalues[0].name
arg_name_as_id = arg_name + '_id'
rvalue = member.rvalue
if isinstance(rvalue, CallExpr):
if not isinstance(rvalue.callee, RefExpr):
return None
if rvalue.callee.fullname in REFERENCING_DB_FIELDS:
if rvalue.callee.fullname == 'django.db.models.fields.related.ForeignKey':
model_definition.cls.info.names[arg_name_as_id] = \
model_definition.api.lookup_fully_qualified('builtins.int')
if rvalue.callee.fullname == 'django.db.models.fields.related.OneToOneField':
if 'related_name' in rvalue.arg_names:
referred_to_model = rvalue.args[rvalue.arg_names.index('to')]
related_arg_value = rvalue.args[rvalue.arg_names.index('related_name')].value
if isinstance(referred_to_model, StrExpr):
referred_model_fullname = get_app_model(referred_to_model.value)
else:
referred_model_fullname = referred_to_model.fullname
referred_model = model_definition.api.lookup_fully_qualified_or_none(referred_model_fullname)
referred_model.node.names[related_arg_value] = \
model_definition.api.lookup_fully_qualified_or_none(model_definition.cls.fullname)
return save_referred_to_model_in_metadata(rvalue)
class BaseDjangoModelsPlugin(Plugin):
model_registry = DjangoModelsRegistry()
def get_base_class_hook(self, fullname: str
) -> Optional[Callable[[ClassDefContext], None]]:
if fullname in self.model_registry:
return CollectModelsInformation(self.model_registry)
return None