def _parse_converter(ctx: 'mypy.plugin.ClassDefContext',
converter: Optional[Expression]) -> Converter:
"""Return the Converter object from an Expression."""
# TODO: Support complex converters, e.g. lambdas, calls, etc.
if converter:
if isinstance(converter, RefExpr) and converter.node:
if (isinstance(converter.node, FuncDef) and converter.node.type
and isinstance(converter.node.type, FunctionLike)):
return Converter(converter.node.type)
elif (isinstance(converter.node, OverloadedFuncDef)
and is_valid_overloaded_converter(converter.node)):
return Converter(converter.node.type)
elif isinstance(converter.node, TypeInfo):
from mypy.checkmember import type_object_type # To avoid import cycle.
return Converter(
type_object_type(converter.node, ctx.api.named_type))
if (isinstance(converter, CallExpr)
and isinstance(converter.callee, RefExpr)
and converter.callee.fullname in attr_optional_converters
and converter.args and converter.args[0]):
# Special handling for attr.converters.optional(type)
# We extract the type and add make the init_args Optional in Attribute.argument
argument = _parse_converter(ctx, converter.args[0])
argument.is_attr_converters_optional = True
return argument
# Signal that we have an unsupported converter.
ctx.api.fail(
"Unsupported converter, only named functions and types are currently supported",
converter)
return Converter(None, is_invalid_converter=True)
return Converter(None)
def _collect_args(ctx, expr: Expression):
if isinstance(expr, DictExpr):
for key, value in expr.items:
if not isinstance(key, StrExpr):
ctx.api.fail('Must be a string for the keys', expr)
return
if not isinstance(value, NameExpr):
ctx.api.fail('Must be a typing definition', expr)
return
from mypy.checkmember import type_object_type # To avoid import cycle.
converter_type = type_object_type(value.node, ctx.api.builtin_type)
yield key.value, converter_type.items()[0].arg_types, value.node
def argument(self, ctx: 'mypy.plugin.ClassDefContext') -> Argument:
"""Return this attribute as an argument to __init__."""
assert self.init
init_type = self.init_type or self.info[self.name].type
if self.converter.name:
# When a converter is set the init_type is overridden by the first argument
# of the converter method.
converter = lookup_qualified_stnode(ctx.api.modules, self.converter.name, True)
if not converter:
# The converter may be a local variable. Check there too.
converter = ctx.api.lookup_qualified(self.converter.name, self.info, True)
# Get the type of the converter.
converter_type = None # type: Optional[Type]
if converter and isinstance(converter.node, TypeInfo):
from mypy.checkmember import type_object_type # To avoid import cycle.
converter_type = type_object_type(converter.node, ctx.api.builtin_type)
elif converter and isinstance(converter.node, OverloadedFuncDef):
converter_type = converter.node.type
elif converter and converter.type:
converter_type = converter.type
init_type = None
converter_type = get_proper_type(converter_type)
if isinstance(converter_type, CallableType) and converter_type.arg_types:
init_type = ctx.api.anal_type(converter_type.arg_types[0])
elif isinstance(converter_type, Overloaded):
types = [] # type: List[Type]
for item in converter_type.items():
# Walk the overloads looking for methods that can accept one argument.
num_arg_types = len(item.arg_types)
if not num_arg_types:
continue
if num_arg_types > 1 and any(kind == ARG_POS for kind in item.arg_kinds[1:]):
continue
types.append(item.arg_types[0])
# Make a union of all the valid types.
if types:
args = make_simplified_union(types)
init_type = ctx.api.anal_type(args)
if self.converter.is_attr_converters_optional and init_type:
# If the converter was attr.converter.optional(type) then add None to
# the allowed init_type.
init_type = UnionType.make_union([init_type, NoneType()])
if not init_type:
ctx.api.fail("Cannot determine __init__ type from converter", self.context)
init_type = AnyType(TypeOfAny.from_error)
elif self.converter.name == '':
# This means we had a converter but it's not of a type we can infer.
# Error was shown in _get_converter_name
init_type = AnyType(TypeOfAny.from_error)
if init_type is None:
if ctx.api.options.disallow_untyped_defs:
# This is a compromise. If you don't have a type here then the
# __init__ will be untyped. But since the __init__ is added it's
# pointing at the decorator. So instead we also show the error in the
# assignment, which is where you would fix the issue.
node = self.info[self.name].node
assert node is not None
ctx.api.msg.need_annotation_for_var(node, self.context)
# Convert type not set to Any.
init_type = AnyType(TypeOfAny.unannotated)
if self.kw_only:
arg_kind = ARG_NAMED_OPT if self.has_default else ARG_NAMED
else:
arg_kind = ARG_OPT if self.has_default else ARG_POS
# Attrs removes leading underscores when creating the __init__ arguments.
return Argument(Var(self.name.lstrip("_"), init_type), init_type,
None,
arg_kind)
def argument(self, ctx: 'mypy.plugin.ClassDefContext') -> Argument:
"""Return this attribute as an argument to __init__."""
assert self.init
init_type = self.info[self.name].type
if self.converter.name:
# When a converter is set the init_type is overridden by the first argument
# of the converter method.
converter = lookup_qualified_stnode(ctx.api.modules, self.converter.name, True)
if not converter:
# The converter may be a local variable. Check there too.
converter = ctx.api.lookup_qualified(self.converter.name, self.info, True)
# Get the type of the converter.
converter_type = None
if converter and isinstance(converter.node, TypeInfo):
from mypy.checkmember import type_object_type # To avoid import cycle.
converter_type = type_object_type(converter.node, ctx.api.builtin_type)
elif converter and isinstance(converter.node, OverloadedFuncDef):
converter_type = converter.node.type
elif converter and converter.type:
converter_type = converter.type
init_type = None
if isinstance(converter_type, CallableType) and converter_type.arg_types:
init_type = ctx.api.anal_type(converter_type.arg_types[0])
elif isinstance(converter_type, Overloaded):
types = [] # type: List[Type]
for item in converter_type.items():
# Walk the overloads looking for methods that can accept one argument.
num_arg_types = len(item.arg_types)
if not num_arg_types:
continue
if num_arg_types > 1 and any(kind == ARG_POS for kind in item.arg_kinds[1:]):
continue
types.append(item.arg_types[0])
# Make a union of all the valid types.
if types:
args = UnionType.make_simplified_union(types)
init_type = ctx.api.anal_type(args)
if self.converter.is_attr_converters_optional and init_type:
# If the converter was attr.converter.optional(type) then add None to
# the allowed init_type.
init_type = UnionType.make_union([init_type, NoneTyp()])
if not init_type:
ctx.api.fail("Cannot determine __init__ type from converter", self.context)
init_type = AnyType(TypeOfAny.from_error)
elif self.converter.name == '':
# This means we had a converter but it's not of a type we can infer.
# Error was shown in _get_converter_name
init_type = AnyType(TypeOfAny.from_error)
if init_type is None:
if ctx.api.options.disallow_untyped_defs:
# This is a compromise. If you don't have a type here then the
# __init__ will be untyped. But since the __init__ is added it's
# pointing at the decorator. So instead we also show the error in the
# assignment, which is where you would fix the issue.
node = self.info[self.name].node
assert node is not None
ctx.api.msg.need_annotation_for_var(node, self.context)
# Convert type not set to Any.
init_type = AnyType(TypeOfAny.unannotated)
if self.kw_only:
arg_kind = ARG_NAMED_OPT if self.has_default else ARG_NAMED
else:
arg_kind = ARG_OPT if self.has_default else ARG_POS
# Attrs removes leading underscores when creating the __init__ arguments.
return Argument(Var(self.name.lstrip("_"), init_type), init_type,
None,
arg_kind)
