def _maybe_unroll_union(cls, info: TypeInfo) -> TypeInfo:
if is_union(info.type):
assert len(info.args) > 1
if cls._all_types_match(ModelT, info.args):
return _TypeInfo_from_type(ModelT, optional=info.is_optional)
elif cls._all_types_match(LITERAL_TYPES, info.args):
return _TypeInfo_from_type(info.args[0],
optional=info.is_optional)
return info
def create_if_compatible(cls, typ: Type, *,
root: 'RootNode') -> Optional['Node']:
if is_union(typ):
return cls(typ, root=root)
return None
def test_is_union(input, expected):
assert is_union(input) == expected