def visit_asyncwith(self, node):
for ctx_mgr, _ in node.items:
inferred = checker_utils.safe_infer(ctx_mgr)
if inferred is None or inferred is astroid.Uninferable:
continue
if isinstance(inferred, astroid.AsyncFunctionDef):
# Check if we are dealing with a function decorated
# with contextlib.asynccontextmanager.
if decorated_with(inferred, self._async_generators):
continue
elif isinstance(inferred, bases.AsyncGenerator):
# Check if we are dealing with a function decorated
# with contextlib.asynccontextmanager.
if decorated_with(inferred.parent, self._async_generators):
continue
else:
try:
inferred.getattr("__aenter__")
inferred.getattr("__aexit__")
except exceptions.NotFoundError:
if isinstance(inferred, astroid.Instance):
# If we do not know the bases of this class,
# just skip it.
if not checker_utils.has_known_bases(inferred):
continue
# Just ignore mixin classes.
if self._ignore_mixin_members:
if inferred.name[-5:].lower() == "mixin":
continue
else:
continue
self.add_message("not-async-context-manager",
node=node,
args=(inferred.name, ))
def visit_with(self, node):
for ctx_mgr, _ in node.items:
context = astroid.context.InferenceContext()
infered = safe_infer(ctx_mgr, context=context)
if infered is None or infered is astroid.YES:
continue
if isinstance(infered, bases.Generator):
# Check if we are dealing with a function decorated
# with contextlib.contextmanager.
if decorated_with(infered.parent,
self.config.contextmanager_decorators):
continue
# If the parent of the generator is not the context manager itself,
# that means that it could have been returned from another
# function which was the real context manager.
# The following approach is more of a hack rather than a real
# solution: walk all the inferred statements for the
# given *ctx_mgr* and if you find one function scope
# which is decorated, consider it to be the real
# manager and give up, otherwise emit not-context-manager.
# See the test file for not_context_manager for a couple
# of self explaining tests.
for path in six.moves.filter(None, _unflatten(context.path)):
scope = path.scope()
if not isinstance(scope, astroid.FunctionDef):
continue
if decorated_with(scope,
self.config.contextmanager_decorators):
break
else:
self.add_message('not-context-manager',
node=node,
args=(infered.name, ))
else:
try:
infered.getattr('__enter__')
infered.getattr('__exit__')
except exceptions.NotFoundError:
if isinstance(infered, astroid.Instance):
# If we do not know the bases of this class,
# just skip it.
if not has_known_bases(infered):
continue
# Just ignore mixin classes.
if self.config.ignore_mixin_members:
if infered.name[-5:].lower() == 'mixin':
continue
self.add_message('not-context-manager',
node=node,
args=(infered.name, ))
def visit_with(self, node):
for ctx_mgr, _ in node.items:
context = astroid.context.InferenceContext()
infered = safe_infer(ctx_mgr, context=context)
if infered is None or infered is astroid.YES:
continue
if isinstance(infered, bases.Generator):
# Check if we are dealing with a function decorated
# with contextlib.contextmanager.
if decorated_with(infered.parent,
self.config.contextmanager_decorators):
continue
# If the parent of the generator is not the context manager itself,
# that means that it could have been returned from another
# function which was the real context manager.
# The following approach is more of a hack rather than a real
# solution: walk all the inferred statements for the
# given *ctx_mgr* and if you find one function scope
# which is decorated, consider it to be the real
# manager and give up, otherwise emit not-context-manager.
# See the test file for not_context_manager for a couple
# of self explaining tests.
for path in six.moves.filter(None, _unflatten(context.path)):
scope = path.scope()
if not isinstance(scope, astroid.FunctionDef):
continue
if decorated_with(scope,
self.config.contextmanager_decorators):
break
else:
self.add_message('not-context-manager',
node=node, args=(infered.name, ))
else:
try:
infered.getattr('__enter__')
infered.getattr('__exit__')
except exceptions.NotFoundError:
if isinstance(infered, astroid.Instance):
# If we do not know the bases of this class,
# just skip it.
if not has_known_bases(infered):
continue
# Just ignore mixin classes.
if self.config.ignore_mixin_members:
if infered.name[-5:].lower() == 'mixin':
continue
self.add_message('not-context-manager',
node=node, args=(infered.name, ))
def visit_asyncwith(self, node):
for ctx_mgr, _ in node.items:
inferred = checker_utils.safe_infer(ctx_mgr)
if inferred is None or inferred is astroid.Uninferable:
continue
if isinstance(inferred, bases.AsyncGenerator):
# Check if we are dealing with a function decorated
# with contextlib.asynccontextmanager.
if decorated_with(inferred.parent, self._async_generators):
continue
else:
try:
inferred.getattr("__aenter__")
inferred.getattr("__aexit__")
except exceptions.NotFoundError:
if isinstance(inferred, astroid.Instance):
# If we do not know the bases of this class,
# just skip it.
if not checker_utils.has_known_bases(inferred):
continue
# Just ignore mixin classes.
if self._ignore_mixin_members:
if inferred.name[-5:].lower() == "mixin":
continue
else:
continue
self.add_message(
"not-async-context-manager", node=node, args=(inferred.name,)
)
def visit_asyncwith(self, node: nodes.AsyncWith) -> None:
for ctx_mgr, _ in node.items:
inferred = checker_utils.safe_infer(ctx_mgr)
if inferred is None or inferred is astroid.Uninferable:
continue
if isinstance(inferred, nodes.AsyncFunctionDef):
# Check if we are dealing with a function decorated
# with contextlib.asynccontextmanager.
if decorated_with(inferred, self._async_generators):
continue
elif isinstance(inferred, astroid.bases.AsyncGenerator):
# Check if we are dealing with a function decorated
# with contextlib.asynccontextmanager.
if decorated_with(inferred.parent, self._async_generators):
continue
else:
try:
inferred.getattr("__aenter__")
inferred.getattr("__aexit__")
except astroid.exceptions.NotFoundError:
if isinstance(inferred, astroid.Instance):
# If we do not know the bases of this class,
# just skip it.
if not checker_utils.has_known_bases(inferred):
continue
# Ignore mixin classes if they match the rgx option.
if ("not-async-context-manager" in
self.linter.namespace.ignored_checks_for_mixins
and self._mixin_class_rgx.match(
inferred.name)):
continue
else:
continue
self.add_message("not-async-context-manager",
node=node,
args=(inferred.name, ))
def _check_unexpected_method_signature(self, node):
expected_params = SPECIAL_METHODS_PARAMS[node.name]
if expected_params is None:
# This can support a variable number of parameters.
return
if not node.args.args and not node.args.vararg:
# Method has no parameter, will be caught
# by no-method-argument.
return
if decorated_with(node, ["builtins.staticmethod"]):
# We expect to not take in consideration self.
all_args = node.args.args
else:
all_args = node.args.args[1:]
mandatory = len(all_args) - len(node.args.defaults)
optional = len(node.args.defaults)
current_params = mandatory + optional
emit = False # If we don't know we choose a false negative
if isinstance(expected_params, tuple):
# The expected number of parameters can be any value from this
# tuple, although the user should implement the method
# to take all of them in consideration.
emit = mandatory not in expected_params
# pylint: disable-next=consider-using-f-string
expected_params = "between %d or %d" % expected_params
else:
# If the number of mandatory parameters doesn't
# suffice, the expected parameters for this
# function will be deduced from the optional
# parameters.
rest = expected_params - mandatory
if rest == 0:
emit = False
elif rest < 0:
emit = True
elif rest > 0:
emit = not ((optional - rest) >= 0 or node.args.vararg)
if emit:
verb = "was" if current_params <= 1 else "were"
self.add_message(
"unexpected-special-method-signature",
args=(node.name, expected_params, current_params, verb),
node=node,
)
def _check_unexpected_method_signature(self, node):
expected_params = SPECIAL_METHODS_PARAMS[node.name]
if expected_params is None:
# This can support a variable number of parameters.
return
if not len(node.args.args) and not node.args.vararg:
# Method has no parameter, will be catched
# by no-method-argument.
return
if decorated_with(node, [BUILTINS + ".staticmethod"]):
# We expect to not take in consideration self.
all_args = node.args.args
else:
all_args = node.args.args[1:]
mandatory = len(all_args) - len(node.args.defaults)
optional = len(node.args.defaults)
current_params = mandatory + optional
if isinstance(expected_params, tuple):
# The expected number of parameters can be any value from this
# tuple, although the user should implement the method
# to take all of them in consideration.
emit = mandatory not in expected_params
expected_params = "between %d or %d" % expected_params
else:
# If the number of mandatory parameters doesn't
# suffice, the expected parameters for this
# function will be deduced from the optional
# parameters.
rest = expected_params - mandatory
if rest == 0:
emit = False
elif rest < 0:
emit = True
elif rest > 0:
emit = not ((optional - rest) >= 0 or node.args.vararg)
if emit:
verb = "was" if current_params <= 1 else "were"
self.add_message('unexpected-special-method-signature',
args=(node.name, expected_params, current_params, verb),
node=node)
def visit_functiondef(self, node):
if node.is_method():
if node.name in self._unused_magic_methods:
method_name = node.name
if node.name.startswith('__'):
method_name = node.name[2:-2]
self.add_message(method_name + '-method', node=node)
elif node.name == 'next':
# If there is a method named `next` declared, if it is invokable
# with zero arguments then it implements the Iterator protocol.
# This means if the method is an instance method or a
# classmethod 1 argument should cause a failure, if it is a
# staticmethod 0 arguments should cause a failure.
failing_arg_count = 1
if utils.decorated_with(node,
[bases.BUILTINS + ".staticmethod"]):
failing_arg_count = 0
if len(node.args.args) == failing_arg_count:
self.add_message('next-method-defined', node=node)
def visit_functiondef(self, node):
if node.is_method():
if node.name in self._unused_magic_methods:
method_name = node.name
if node.name.startswith('__'):
method_name = node.name[2:-2]
self.add_message(method_name + '-method', node=node)
elif node.name == 'next':
# If there is a method named `next` declared, if it is invokable
# with zero arguments then it implements the Iterator protocol.
# This means if the method is a instance method or a
# classmethod 1 argument should cause a failure, if it is a
# staticmethod 0 arguments should cause a failure.
failing_arg_count = 1
if utils.decorated_with(node,
[bases.BUILTINS + ".staticmethod"]):
failing_arg_count = 0
if len(node.args.args) == failing_arg_count:
self.add_message('next-method-defined', node=node)
def visit_with(self, node):
for ctx_mgr, _ in node.items:
infered = safe_infer(ctx_mgr)
if infered is None or infered is astroid.YES:
continue
# Check if we are dealing with a function decorated
# with contextlib.contextmanager.
if isinstance(infered, astroid.bases.Generator):
func = infered.parent
if not decorated_with(func, ['contextlib.contextmanager']):
self.add_message('not-context-manager',
node=node, args=(infered.name, ))
else:
try:
infered.getattr('__enter__')
infered.getattr('__exit__')
except astroid.NotFoundError:
self.add_message('not-context-manager',
node=node, args=(infered.name, ))
