Files
django-stubs/mypy_django_plugin/plugins/related_fields.py
2018-11-11 02:08:05 +03:00

41 lines
1.4 KiB
Python

from typing import Optional, Callable
from mypy.nodes import SymbolTableNode, MDEF, Var
from mypy.plugin import Plugin, FunctionContext
from mypy.types import Type, CallableType, TypeOfAny, AnyType, Instance
def set_related_fields(ctx: FunctionContext) -> Type:
if 'related_name' not in ctx.context.arg_names:
return ctx.default_return_type
assert 'to' in ctx.context.arg_names
to_arg_value = ctx.arg_types[ctx.context.arg_names.index('to')][0]
if not isinstance(to_arg_value, CallableType):
return ctx.default_return_type
referred_to = to_arg_value.ret_type
related_name = ctx.context.args[ctx.context.arg_names.index('related_name')].value
outer_class_info = ctx.api.tscope.classes[-1]
queryset_type = ctx.api.named_generic_type('django.db.models.QuerySet',
args=[Instance(outer_class_info, [])])
related_var = Var(related_name,
queryset_type)
related_var.info = queryset_type.type
referred_to.type.names[related_name] = SymbolTableNode(MDEF, related_var)
return ctx.default_return_type
class RelatedFieldsPlugin(Plugin):
def get_function_hook(self, fullname: str
) -> Optional[Callable[[FunctionContext], Type]]:
if fullname == 'django.db.models.fields.related.ForeignKey':
return set_related_fields
return None
def plugin(version):
return RelatedFieldsPlugin