# Copyright 2008-2015 Nokia Networks
# Copyright 2016- Robot Framework Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from abc import ABC, abstractmethod
from inspect import isclass, signature, Parameter
from typing import Any, Callable, get_type_hints
from robot.errors import DataError
from robot.utils import is_string, split_from_equals
from robot.variables import is_assign, is_scalar_assign
from .argumentspec import ArgumentSpec
[docs]
class ArgumentParser(ABC):
def __init__(self, type: str = 'Keyword',
error_reporter: 'Callable[[str], None] | None' = None):
self.type = type
self.error_reporter = error_reporter
[docs]
@abstractmethod
def parse(self, source: Any, name: 'str|None' = None) -> ArgumentSpec:
raise NotImplementedError
def _report_error(self, error: str):
if self.error_reporter:
self.error_reporter(error)
else:
raise DataError(f'Invalid argument specification: {error}')
[docs]
class PythonArgumentParser(ArgumentParser):
[docs]
def parse(self, method, name=None):
try:
sig = signature(method)
except ValueError: # Can occur with C functions (incl. many builtins).
return ArgumentSpec(name, self.type, var_positional='args')
except TypeError as err: # Occurs if handler isn't actually callable.
raise DataError(str(err))
parameters = list(sig.parameters.values())
# `inspect.signature` drops `self` with bound methods and that's the case when
# inspecting keywords. `__init__` is got directly from class (i.e. isn't bound)
# so we need to handle that case ourselves.
# Partial objects do not have __name__ at least in Python =< 3.10.
if getattr(method, '__name__', None) == '__init__':
parameters = parameters[1:]
spec = self._create_spec(parameters, name)
self._set_types(spec, method)
return spec
def _create_spec(self, parameters, name):
positional_only = []
positional_or_named = []
var_positional = None
named_only = []
var_named = None
defaults = {}
for param in parameters:
kind = param.kind
if kind == Parameter.POSITIONAL_ONLY:
positional_only.append(param.name)
elif kind == Parameter.POSITIONAL_OR_KEYWORD:
positional_or_named.append(param.name)
elif kind == Parameter.VAR_POSITIONAL:
var_positional = param.name
elif kind == Parameter.KEYWORD_ONLY:
named_only.append(param.name)
elif kind == Parameter.VAR_KEYWORD:
var_named = param.name
if param.default is not param.empty:
defaults[param.name] = param.default
return ArgumentSpec(name, self.type, positional_only, positional_or_named,
var_positional, named_only, var_named, defaults)
def _set_types(self, spec, method):
types = self._get_types(method)
if isinstance(types, dict) and 'return' in types:
spec.return_type = types.pop('return')
spec.types = types
def _get_types(self, method):
# If types are set using the `@keyword` decorator, use them. Including when
# types are explicitly disabled with `@keyword(types=None)`. Otherwise get
# type hints.
if isclass(method):
method = method.__init__
types = getattr(method, 'robot_types', ())
if types or types is None:
return types
try:
return get_type_hints(method)
except Exception: # Can raise pretty much anything
# Not all functions have `__annotations__`.
# https://github.com/robotframework/robotframework/issues/4059
return getattr(method, '__annotations__', {})
[docs]
class ArgumentSpecParser(ArgumentParser):
[docs]
def parse(self, arguments, name=None):
positional_only = []
positional_or_named = []
var_positional = None
named_only = []
var_named = None
defaults = {}
named_only_separator_seen = positional_only_separator_seen = False
target = positional_or_named
for arg in arguments:
arg = self._validate_arg(arg)
if var_named:
self._report_error('Only last argument can be kwargs.')
elif self._is_positional_only_separator(arg):
if positional_only_separator_seen:
self._report_error('Too many positional-only separators.')
if named_only_separator_seen:
self._report_error('Positional-only separator must be before '
'named-only arguments.')
positional_only = positional_or_named
target = positional_or_named = []
positional_only_separator_seen = True
elif isinstance(arg, tuple):
arg, default = arg
arg = self._format_arg(arg)
target.append(arg)
defaults[arg] = default
elif self._is_var_named(arg):
var_named = self._format_var_named(arg)
elif self._is_var_positional(arg):
if named_only_separator_seen:
self._report_error('Cannot have multiple varargs.')
if not self._is_named_only_separator(arg):
var_positional = self._format_var_positional(arg)
named_only_separator_seen = True
target = named_only
elif defaults and not named_only_separator_seen:
self._report_error('Non-default argument after default arguments.')
else:
arg = self._format_arg(arg)
target.append(arg)
return ArgumentSpec(name, self.type, positional_only, positional_or_named,
var_positional, named_only, var_named, defaults)
@abstractmethod
def _validate_arg(self, arg):
raise NotImplementedError
@abstractmethod
def _is_var_named(self, arg):
raise NotImplementedError
@abstractmethod
def _format_var_named(self, kwargs):
raise NotImplementedError
@abstractmethod
def _is_positional_only_separator(self, arg):
raise NotImplementedError
@abstractmethod
def _is_named_only_separator(self, arg):
raise NotImplementedError
@abstractmethod
def _is_var_positional(self, arg):
raise NotImplementedError
@abstractmethod
def _format_var_positional(self, varargs):
raise NotImplementedError
def _format_arg(self, arg):
return arg
def _add_arg(self, spec, arg, named_only=False):
arg = self._format_arg(arg)
target = spec.positional_or_named if not named_only else spec.named_only
target.append(arg)
return arg
[docs]
class DynamicArgumentParser(ArgumentSpecParser):
def _validate_arg(self, arg):
if isinstance(arg, tuple):
if self._is_invalid_tuple(arg):
self._report_error(f'Invalid argument "{arg}".')
if len(arg) == 1:
return arg[0]
return arg
if '=' in arg:
return tuple(arg.split('=', 1))
return arg
def _is_invalid_tuple(self, arg):
return (len(arg) > 2
or not is_string(arg[0])
or (arg[0].startswith('*') and len(arg) > 1))
def _is_var_named(self, arg):
return arg[:2] == '**'
def _format_var_named(self, kwargs):
return kwargs[2:]
def _is_var_positional(self, arg):
return arg and arg[0] == '*'
def _is_positional_only_separator(self, arg):
return arg == '/'
def _is_named_only_separator(self, arg):
return arg == '*'
def _format_var_positional(self, varargs):
return varargs[1:]
[docs]
class UserKeywordArgumentParser(ArgumentSpecParser):
def _validate_arg(self, arg):
arg, default = split_from_equals(arg)
if not (is_assign(arg) or arg == '@{}'):
self._report_error(f"Invalid argument syntax '{arg}'.")
if default is None:
return arg
if not is_scalar_assign(arg):
typ = 'list' if arg[0] == '@' else 'dictionary'
self._report_error(f"Only normal arguments accept default values, "
f"{typ} arguments like '{arg}' do not.")
return arg, default
def _is_var_named(self, arg):
return arg and arg[0] == '&'
def _format_var_named(self, kwargs):
return kwargs[2:-1]
def _is_var_positional(self, arg):
return arg and arg[0] == '@'
def _is_positional_only_separator(self, arg):
return False
def _is_named_only_separator(self, arg):
return arg == '@{}'
def _format_var_positional(self, varargs):
return varargs[2:-1]
def _format_arg(self, arg):
return arg[2:-1]