# coding: utf-8
#
# Copyright 2015 Palantir Technologies, Inc.
#
# 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.
"""Logic for checking parameter declarations and parameter types."""
from __future__ import absolute_import, division, print_function
import inspect
import six
from .errors import InvalidParamsError, InvalidReturnTypeError
[docs]def validate_params_match(method, parameters):
"""Validates that the given parameters are exactly the method's declared parameters.
:param method: The method to be called
:type method: function
:param parameters: The parameters to use in the call
:type parameters: dict[str, object] | list[object]
"""
argspec = inspect.getargspec(method) # pylint: disable=deprecated-method
default_length = len(argspec.defaults) if argspec.defaults is not None else 0
if isinstance(parameters, list):
if len(parameters) > len(argspec.args) and argspec.varargs is None:
raise InvalidParamsError("Too many parameters")
remaining_parameters = len(argspec.args) - len(parameters)
if remaining_parameters > default_length:
raise InvalidParamsError("Not enough parameters")
elif isinstance(parameters, dict):
missing_parameters = [key for key in argspec.args if key not in parameters]
default_parameters = set(argspec.args[len(argspec.args) - default_length:])
for key in missing_parameters:
if key not in default_parameters:
raise InvalidParamsError("Parameter {} has not been satisfied".format(key))
extra_params = [key for key in parameters if key not in argspec.args]
if len(extra_params) > 0 and argspec.keywords is None:
raise InvalidParamsError("Too many parameters")
[docs]def check_types(parameters, parameter_types, strict_floats):
"""Checks that the given parameters have the correct types.
:param parameters: List of (name, value) pairs of the given parameters
:type parameters: dict[str, object]
:param parameter_types: Parameter type by name.
:type parameter_types: dict[str, type]
:param strict_floats: If False, treat integers as floats
:type strict_floats: bool
"""
for name, parameter_type in parameter_types.items():
if name not in parameters:
raise InvalidParamsError("Parameter '{}' is missing.".format(name))
if not _is_instance(parameters[name], parameter_type, strict_floats):
raise InvalidParamsError("Value '{}' for parameter '{}' is not of expected type {}."
.format(parameters[name], name, parameter_type))
[docs]def check_type_declaration(parameter_names, parameter_types):
"""Checks that exactly the given parameter names have declared types.
:param parameter_names: The names of the parameters in the method declaration
:type parameter_names: list[str]
:param parameter_types: Parameter type by name
:type parameter_types: dict[str, type]
"""
if len(parameter_names) != len(parameter_types):
raise Exception("Number of method parameters ({}) does not match number of "
"declared types ({})"
.format(len(parameter_names), len(parameter_types)))
for parameter_name in parameter_names:
if parameter_name not in parameter_types:
raise Exception("Parameter '{}' does not have a declared type".format(parameter_name))
[docs]def check_return_type(value, expected_type, strict_floats):
"""Checks that the given return value has the correct type.
:param value: Value returned by the method
:type value: object
:param expected_type: Expected return type
:type expected_type: type
:param strict_floats: If False, treat integers as floats
:type strict_floats: bool
"""
if expected_type is None:
if value is not None:
raise InvalidReturnTypeError("Returned value is '{}' but None was expected"
.format(value))
elif not _is_instance(value, expected_type, strict_floats):
raise InvalidReturnTypeError("Type of return value '{}' does not match expected type {}"
.format(value, expected_type))
def _is_instance(value, expected_type, strict_floats):
if expected_type is float and not strict_floats:
return isinstance(value, (six.integer_types, float))
if expected_type in six.integer_types:
return isinstance(value, six.integer_types)
return isinstance(value, expected_type)