def extract_ref_to_fullname(rvalue_expr: CallExpr,
module_file: MypyFile, all_modules: Dict[str, MypyFile]) -> Optional[str]:
if 'to' in rvalue_expr.arg_names:
to_expr = rvalue_expr.args[rvalue_expr.arg_names.index('to')]
else:
to_expr = rvalue_expr.args[0]
if isinstance(to_expr, NameExpr):
return module_file.names[to_expr.name].fullname
elif isinstance(to_expr, StrExpr):
typ_fullname = helpers.get_model_fullname_from_string(to_expr.value, all_modules)
if typ_fullname is None:
return None
return typ_fullname
return None
def extract_referred_to_type(ctx: FunctionContext) -> Optional[Instance]:
api = cast(TypeChecker, ctx.api)
if 'to' not in ctx.callee_arg_names:
api.msg.fail(
f'to= parameter must be set for {ctx.context.callee.fullname}',
context=ctx.context)
return None
arg_type = ctx.arg_types[ctx.callee_arg_names.index('to')][0]
if not isinstance(arg_type, CallableType):
to_arg_expr = ctx.args[ctx.callee_arg_names.index('to')][0]
if not isinstance(to_arg_expr, StrExpr):
# not string, not supported
return None
try:
model_fullname = helpers.get_model_fullname_from_string(
to_arg_expr.value, all_modules=api.modules)
except helpers.SelfReference:
model_fullname = api.tscope.classes[-1].fullname()
except helpers.SameFileModel as exc:
model_fullname = api.tscope.classes[
-1].module_name + '.' + exc.model_cls_name
if model_fullname is None:
return None
model_info = helpers.lookup_fully_qualified_generic(
model_fullname, all_modules=api.modules)
if model_info is None or not isinstance(model_info, TypeInfo):
return None
return Instance(model_info, [])
referred_to_type = arg_type.ret_type
if not isinstance(referred_to_type, Instance):
return None
if not referred_to_type.type.has_base(helpers.MODEL_CLASS_FULLNAME):
ctx.api.msg.fail(
f'to= parameter value must be '
f'a subclass of {helpers.MODEL_CLASS_FULLNAME}',
context=ctx.context)
return None
return referred_to_type
