Files
django-stubs/mypy_django_plugin/transformers/init_create.py
Maxim Kurnikov 02bdf5be95 add support for typechecking of filter/get/exclude arguments (#183)
* add support for typechecking of filter/get/exclude arguments

* linting
2019-09-30 03:05:40 +03:00

119 lines
5.1 KiB
Python

from typing import List, Tuple, Type, Union
from django.db.models.base import Model
from mypy.plugin import FunctionContext, MethodContext
from mypy.types import Instance
from mypy.types import Type as MypyType
from mypy_django_plugin.django.context import DjangoContext
from mypy_django_plugin.lib import fullnames, helpers
def get_actual_types(ctx: Union[MethodContext, FunctionContext],
expected_keys: List[str]) -> List[Tuple[str, MypyType]]:
actual_types = []
# positionals
for pos, (actual_name, actual_type) in enumerate(zip(ctx.arg_names[0], ctx.arg_types[0])):
if actual_name is None:
if ctx.callee_arg_names[0] == 'kwargs':
# unpacked dict as kwargs is not supported
continue
actual_name = expected_keys[pos]
actual_types.append((actual_name, actual_type))
# kwargs
if len(ctx.callee_arg_names) > 1:
for actual_name, actual_type in zip(ctx.arg_names[1], ctx.arg_types[1]):
if actual_name is None:
# unpacked dict as kwargs is not supported
continue
actual_types.append((actual_name, actual_type))
return actual_types
def check_types_compatible(ctx, *, expected_type, actual_type, error_message):
ctx.api.check_subtype(actual_type, expected_type,
ctx.context, error_message,
'got', 'expected')
def typecheck_model_method(ctx: Union[FunctionContext, MethodContext], django_context: DjangoContext,
model_cls: Type[Model], method: str) -> MypyType:
typechecker_api = helpers.get_typechecker_api(ctx)
expected_types = django_context.get_expected_types(typechecker_api, model_cls, method=method)
expected_keys = [key for key in expected_types.keys() if key != 'pk']
for actual_name, actual_type in get_actual_types(ctx, expected_keys):
if actual_name not in expected_types:
ctx.api.fail('Unexpected attribute "{}" for model "{}"'.format(actual_name,
model_cls.__name__),
ctx.context)
continue
check_types_compatible(ctx,
expected_type=expected_types[actual_name],
actual_type=actual_type,
error_message='Incompatible type for "{}" of "{}"'.format(actual_name,
model_cls.__name__))
return ctx.default_return_type
def redefine_and_typecheck_model_init(ctx: FunctionContext, django_context: DjangoContext) -> MypyType:
assert isinstance(ctx.default_return_type, Instance)
model_fullname = ctx.default_return_type.type.fullname()
model_cls = django_context.get_model_class_by_fullname(model_fullname)
if model_cls is None:
return ctx.default_return_type
return typecheck_model_method(ctx, django_context, model_cls, '__init__')
def redefine_and_typecheck_model_create(ctx: MethodContext, django_context: DjangoContext) -> MypyType:
if not isinstance(ctx.default_return_type, Instance):
# only work with ctx.default_return_type = model Instance
return ctx.default_return_type
model_fullname = ctx.default_return_type.type.fullname()
model_cls = django_context.get_model_class_by_fullname(model_fullname)
if model_cls is None:
return ctx.default_return_type
return typecheck_model_method(ctx, django_context, model_cls, 'create')
def typecheck_queryset_filter(ctx: MethodContext, django_context: DjangoContext) -> MypyType:
lookup_kwargs = ctx.arg_names[1]
provided_lookup_types = ctx.arg_types[1]
assert isinstance(ctx.type, Instance)
if not ctx.type.args or not isinstance(ctx.type.args[0], Instance):
return ctx.default_return_type
model_cls_fullname = ctx.type.args[0].type.fullname()
model_cls = django_context.get_model_class_by_fullname(model_cls_fullname)
if model_cls is None:
return ctx.default_return_type
for lookup_kwarg, provided_type in zip(lookup_kwargs, provided_lookup_types):
if lookup_kwarg is None:
continue
# Combinables are not supported yet
if (isinstance(provided_type, Instance)
and provided_type.type.has_base('django.db.models.expressions.Combinable')):
continue
lookup_type = django_context.lookups_context.resolve_lookup_expected_type(ctx, model_cls, lookup_kwarg)
# Managers as provided_type is not supported yet
if (isinstance(provided_type, Instance)
and helpers.has_any_of_bases(provided_type.type, (fullnames.MANAGER_CLASS_FULLNAME,
fullnames.QUERYSET_CLASS_FULLNAME))):
return ctx.default_return_type
check_types_compatible(ctx,
expected_type=lookup_type,
actual_type=provided_type,
error_message=f'Incompatible type for lookup {lookup_kwarg!r}:')
return ctx.default_return_type