def _access_member(typ: Type, name: str, ctx: MethodContext) -> Type:
assert isinstance(ctx.api, checker.TypeChecker)
return checkmember.analyze_member_access(
name=name,
typ=typ,
context=ctx.context,
is_lvalue=False,
is_super=False,
is_operator=False,
msg=ctx.api.msg,
original_type=typ,
chk=ctx.api,
)
def attribute_access(ctx: AttributeContext) -> MypyType:
"""
Ensures that attribute access to ``KindN`` is correct.
In other words:
.. code:: python
from typing import TypeVar
from returns.primitives.hkt import KindN
from returns.interfaces.mappable import MappableN
_MappableType = TypeVar('_MappableType', bound=MappableN)
kind: KindN[_MappableType, int, int, int]
reveal_type(kind.map) # will work correctly!
"""
assert isinstance(ctx.type, Instance)
instance = ctx.type.args[0]
if isinstance(instance, TypeVarType):
bound = get_proper_type(instance.upper_bound)
assert isinstance(bound, Instance)
accessed = bound.copy_modified(args=_crop_kind_args(
ctx.type, bound.args), )
elif isinstance(instance, Instance):
accessed = instance.copy_modified(args=_crop_kind_args(ctx.type))
else:
return ctx.default_attr_type
exprchecker = ctx.api.expr_checker # type: ignore
member_type = analyze_member_access(
ctx.context.name, # type: ignore
accessed,
ctx.context,
is_lvalue=False,
is_super=False,
is_operator=False,
msg=ctx.api.msg,
original_type=instance,
chk=ctx.api, # type: ignore
in_literal_context=exprchecker.is_literal_context(),
)
if isinstance(member_type, CallableType):
return detach_callable(member_type)
return member_type
def _get_callable_type(type_: Type,
context: FunctionContext) -> t.Optional[CallableType]:
if isinstance(type_, CallableType):
return type_
# called with an object
elif isinstance(type_, Instance) and type_.has_readable_member('__call__'):
chk: TypeChecker = t.cast(TypeChecker, context.api)
return t.cast(
CallableType,
checkmember.analyze_member_access('__call__',
type_,
context.context,
False,
False,
False,
context.api.msg,
original_type=type_,
chk=chk))
return None
def analyze(ctx: FunctionContext) -> MypyType:
"""
Analyzes several pointfree functions.
Removes intermediate Protocol instances.
"""
callee = ctx.default_return_type
checker = ctx.api.expr_checker # type: ignore
return analyze_member_access(
'__call__',
callee,
ctx.context,
is_lvalue=False,
is_super=False,
is_operator=True,
msg=checker.msg,
original_type=callee,
chk=checker.chk,
in_literal_context=checker.is_literal_context(),
)
def translate_to_function(
function_def: MypyType,
ctx: CallableContext,
) -> MypyType:
"""
Tryies to translate a type into callable by accessing ``__call__`` attr.
This might fail with ``mypy`` errors and that's how must work.
This also preserves all type arguments as-is.
"""
checker = ctx.api.expr_checker # type: ignore
return analyze_member_access(
'__call__',
function_def,
ctx.context,
is_lvalue=False,
is_super=False,
is_operator=True,
msg=checker.msg,
original_type=function_def,
chk=checker.chk,
in_literal_context=checker.is_literal_context(),
)
def visit_class_pattern(self, o: ClassPattern) -> PatternType:
current_type = get_proper_type(self.type_context[-1])
#
# Check class type
#
type_info = o.class_ref.node
assert type_info is not None
if isinstance(type_info, TypeAlias) and not type_info.no_args:
self.msg.fail(message_registry.CLASS_PATTERN_GENERIC_TYPE_ALIAS, o)
return self.early_non_match()
if isinstance(type_info, TypeInfo):
any_type = AnyType(TypeOfAny.implementation_artifact)
typ: Type = Instance(type_info,
[any_type] * len(type_info.defn.type_vars))
elif isinstance(type_info, TypeAlias):
typ = type_info.target
else:
if isinstance(type_info, Var):
name = str(type_info.type)
else:
name = type_info.name
self.msg.fail(
message_registry.CLASS_PATTERN_TYPE_REQUIRED.format(name),
o.class_ref)
return self.early_non_match()
new_type, rest_type = self.chk.conditional_types_with_intersection(
current_type, [get_type_range(typ)], o, default=current_type)
if is_uninhabited(new_type):
return self.early_non_match()
# TODO: Do I need this?
narrowed_type = narrow_declared_type(current_type, new_type)
#
# Convert positional to keyword patterns
#
keyword_pairs: List[Tuple[Optional[str], Pattern]] = []
match_arg_set: Set[str] = set()
captures: Dict[Expression, Type] = {}
if len(o.positionals) != 0:
if self.should_self_match(typ):
if len(o.positionals) > 1:
self.msg.fail(
message_registry.
CLASS_PATTERN_TOO_MANY_POSITIONAL_ARGS, o)
pattern_type = self.accept(o.positionals[0], narrowed_type)
if not is_uninhabited(pattern_type.type):
return PatternType(
pattern_type.type,
join_types(rest_type, pattern_type.rest_type),
pattern_type.captures)
captures = pattern_type.captures
else:
local_errors = self.msg.clean_copy()
match_args_type = analyze_member_access("__match_args__",
typ,
o,
False,
False,
False,
local_errors,
original_type=typ,
chk=self.chk)
if local_errors.is_errors():
self.msg.fail(
message_registry.MISSING_MATCH_ARGS.format(typ), o)
return self.early_non_match()
proper_match_args_type = get_proper_type(match_args_type)
if isinstance(proper_match_args_type, TupleType):
match_arg_names = get_match_arg_names(
proper_match_args_type)
if len(o.positionals) > len(match_arg_names):
self.msg.fail(
message_registry.
CLASS_PATTERN_TOO_MANY_POSITIONAL_ARGS, o)
return self.early_non_match()
else:
match_arg_names = [None] * len(o.positionals)
for arg_name, pos in zip(match_arg_names, o.positionals):
keyword_pairs.append((arg_name, pos))
if arg_name is not None:
match_arg_set.add(arg_name)
#
# Check for duplicate patterns
#
keyword_arg_set = set()
has_duplicates = False
for key, value in zip(o.keyword_keys, o.keyword_values):
keyword_pairs.append((key, value))
if key in match_arg_set:
self.msg.fail(
message_registry.CLASS_PATTERN_KEYWORD_MATCHES_POSITIONAL.
format(key), value)
has_duplicates = True
elif key in keyword_arg_set:
self.msg.fail(
message_registry.CLASS_PATTERN_DUPLICATE_KEYWORD_PATTERN.
format(key), value)
has_duplicates = True
keyword_arg_set.add(key)
if has_duplicates:
return self.early_non_match()
#
# Check keyword patterns
#
can_match = True
for keyword, pattern in keyword_pairs:
key_type: Optional[Type] = None
local_errors = self.msg.clean_copy()
if keyword is not None:
key_type = analyze_member_access(keyword,
narrowed_type,
pattern,
False,
False,
False,
local_errors,
original_type=new_type,
chk=self.chk)
else:
key_type = AnyType(TypeOfAny.from_error)
if local_errors.is_errors() or key_type is None:
key_type = AnyType(TypeOfAny.from_error)
self.msg.fail(
message_registry.CLASS_PATTERN_UNKNOWN_KEYWORD.format(
typ, keyword), value)
inner_type, inner_rest_type, inner_captures = self.accept(
pattern, key_type)
if is_uninhabited(inner_type):
can_match = False
else:
self.update_type_map(captures, inner_captures)
if not is_uninhabited(inner_rest_type):
rest_type = current_type
if not can_match:
new_type = UninhabitedType()
return PatternType(new_type, rest_type, captures)
def process_gql_schema(ctx: AttributeContext) -> Type:
"""
Actually perform the type-checking logic for each graphene `ObjectType` child class.
The plugin is invoked at type-checking time.
"""
assert isinstance(ctx.type, Instance)
object_info = self._graphene_objects[ctx.type.type.fullname]
all_fields = object_info.all_fields if isinstance(
object_info, ObjectTypeInfo) else object_info.fields
# Check that resolver methods are annotated with the correct types
for resolver in object_info.resolvers.values():
gql_field = all_fields.get(resolver.field_name)
if not gql_field:
if isinstance(
object_info,
InterfaceInfo) and resolver.field_name == 'type':
# This is not a field resolver. It is the special `Interface` resolver that determines which
# `ObjectType` to use at runtime.
continue
ctx.api.fail(
f'No field with name "{resolver.field_name}" defined',
resolver.context)
continue
# Check that the resolver's "previous" (first) argument has the correct type
if not is_equivalent(resolver.previous_argument.type,
object_info.runtime_type):
ctx.api.fail(
_get_type_mismatch_error_message(
resolver.previous_argument.name,
graphene_type=object_info.runtime_type,
resolver_type=resolver.previous_argument.type,
),
resolver.previous_argument.context,
)
continue
# Check that the resolver returns the correct type
if not is_subtype(resolver.return_type, gql_field.type):
ctx.api.fail(
f'Resolver returns type {resolver.return_type}, expected type {gql_field.type}',
resolver.context,
)
continue
for field_argument in gql_field.arguments.values():
resolver_argument = resolver.arguments.get(
field_argument.name)
# Check that the resolver has an argument for each argument the `Field()` defines
if not resolver_argument:
ctx.api.fail(
f'Parameter "{field_argument.name}" of type {field_argument.type} is missing,'
' but required in resolver definition',
resolver.context,
)
continue
# Check that the resolver's argument has the correct type annotation
if not is_equivalent(field_argument.type,
resolver_argument.type):
ctx.api.fail(
_get_type_mismatch_error_message(
field_argument.name,
graphene_type=field_argument.type,
resolver_type=resolver_argument.type,
),
resolver_argument.context,
)
continue
# If no resolver function is defined, type-check the behavior of the graphene default resolver
if isinstance(object_info, ObjectTypeInfo):
# The default resolver doesn't apply to `Interface`s because the `ObjectType`s that implement them could
# have resolvers for their fields.
# TODO: Detect if any of an `Interface`'s `ObjectType`s do _not_ define their own resolver for this
# field. In that case, we _do_ want to type-check the default resolver.
fields_without_resolver_names = set(
object_info.fields.keys()) - set(
object_info.resolvers.keys())
for name in fields_without_resolver_names:
gql_field = object_info.fields[name]
# Note: `analyze_member_access` will call `ctx.api.fail()` if the provided type doesn't have
# a member with the given name at all. So our code only needs to do the subtype check.
default_resolver_return_type = analyze_member_access(
gql_field.name,
object_info.runtime_type,
gql_field.context,
False, # is_lvalue
False, # is_super
False, # is_operator
ctx.api.msg,
original_type=object_info.runtime_type,
chk=cast(TypeChecker, ctx.api),
)
if not is_subtype(default_resolver_return_type,
gql_field.type):
ctx.api.fail(
f'Field expects type {gql_field.type} but {object_info.runtime_type}.{gql_field.name} has '
f'type {default_resolver_return_type}',
gql_field.context,
)
continue
return ctx.default_attr_type
