def __init__(self, target, method_name, caller):
"""
:param Target target: The object owning the method to stub.
:param str method_name: The name of the method to stub.
"""
self._target = target
self._method_name = method_name
self._caller = caller
self.args = _any
self.kwargs = _any
self._custom_matcher = None
self._is_satisfied = True
self._call_counter = CallCountAccumulator()
self._return_value = lambda *args, **kwargs: None
def __init__(self, target, method_name, caller):
"""
:param Target target: The object owning the method to stub.
:param str method_name: The name of the method to stub.
"""
self._target = target
self._method_name = method_name
self._caller = caller
self.args = _any
self.kwargs = _any
self._custom_matcher = None
self._is_satisfied = True
self._call_counter = CallCountAccumulator()
self._return_value = lambda *args, **kwargs: None
class Allowance(object):
"""An individual method allowance (stub)."""
def __init__(self, target, method_name, caller):
"""
:param Target target: The object owning the method to stub.
:param str method_name: The name of the method to stub.
"""
self._target = target
self._method_name = method_name
self._caller = caller
self.args = _any
self.kwargs = _any
self._custom_matcher = None
self._is_satisfied = True
self._call_counter = CallCountAccumulator()
self._return_value = lambda *args, **kwargs: None
def and_raise(self, exception, *args, **kwargs):
"""Causes the double to raise the provided exception when called.
If provided, additional arguments (positional and keyword) passed to
`and_raise` are used in the exception instantiation.
:param Exception exception: The exception to raise.
"""
def proxy_exception(*proxy_args, **proxy_kwargs):
raise exception(*args, **kwargs)
self._return_value = proxy_exception
return self
def and_raise_future(self, exception):
"""Similar to `and_raise` but the doubled method returns a future.
:param Exception exception: The exception to raise.
"""
future = _get_future()
future.set_exception(exception)
return self.and_return(future)
def and_return_future(self, *return_values):
"""Similar to `and_return` but the doubled method returns a future.
:param object return_values: The values the double will return when called,
"""
futures = []
for value in return_values:
future = _get_future()
future.set_result(value)
futures.append(future)
return self.and_return(*futures)
def and_return(self, *return_values):
"""Set a return value for an allowance
Causes the double to return the provided values in order. If multiple
values are provided, they are returned one at a time in sequence as the double is called.
If the double is called more times than there are return values, it should continue to
return the last value in the list.
:param object return_values: The values the double will return when called,
"""
if not return_values:
raise TypeError('and_return() expected at least 1 return value')
return_values = list(return_values)
final_value = return_values.pop()
self.and_return_result_of(lambda: return_values.pop(0)
if return_values else final_value)
return self
def and_return_result_of(self, return_value):
""" Causes the double to return the result of calling the provided value.
:param return_value: A callable that will be invoked to determine the double's return value.
:type return_value: any callable object
"""
if not check_func_takes_args(return_value):
self._return_value = lambda *args, **kwargs: return_value()
else:
self._return_value = return_value
return self
def is_satisfied(self):
"""Returns a boolean indicating whether or not the double has been satisfied.
Stubs are always satisfied, but mocks are only satisifed if they've been
called as was declared.
:return: Whether or not the double is satisfied.
:rtype: bool
"""
return self._is_satisfied
def with_args(self, *args, **kwargs):
"""Declares that the double can only be called with the provided arguments.
:param args: Any positional arguments required for invocation.
:param kwargs: Any keyword arguments required for invocation.
"""
self.args = args
self.kwargs = kwargs
self.verify_arguments()
return self
def with_args_validator(self, matching_function):
"""Define a custom function for testing arguments
:param func matching_function: The function used to test arguments passed to the stub.
"""
self.args = None
self.kwargs = None
self._custom_matcher = matching_function
return self
def __call__(self, *args, **kwargs):
"""A short hand syntax for with_args
Allows callers to do:
allow(module).foo.with_args(1, 2)
With:
allow(module).foo(1, 2)
:param args: Any positional arguments required for invocation.
:param kwargs: Any keyword arguments required for invocation.
"""
return self.with_args(*args, **kwargs)
def with_no_args(self):
"""Declares that the double can only be called with no arguments."""
self.args = ()
self.kwargs = {}
self.verify_arguments()
return self
def satisfy_any_args_match(self):
"""Returns a boolean indicating whether or not the stub will accept arbitrary arguments.
This will be true unless the user has specified otherwise using ``with_args`` or
``with_no_args``.
:return: Whether or not the stub accepts arbitrary arguments.
:rtype: bool
"""
return self.args is _any and self.kwargs is _any
def satisfy_exact_match(self, args, kwargs):
"""Returns a boolean indicating whether or not the stub will accept the provided arguments.
:return: Whether or not the stub accepts the provided arguments.
:rtype: bool
"""
if self.args is None and self.kwargs is None:
return False
elif self.args is _any and self.kwargs is _any:
return True
elif args == self.args and kwargs == self.kwargs:
return True
elif len(args) != len(self.args) or len(kwargs) != len(self.kwargs):
return False
if not all(x == y or y == x for x, y in zip(args, self.args)):
return False
for key, value in self.kwargs.items():
if key not in kwargs:
return False
elif not (kwargs[key] == value or value == kwargs[key]):
return False
return True
def satisfy_custom_matcher(self, args, kwargs):
"""Return a boolean indicating if the args satisify the stub
:return: Whether or not the stub accepts the provided arguments.
:rtype: bool
"""
if not self._custom_matcher:
return False
try:
return self._custom_matcher(*args, **kwargs)
except Exception:
return False
def return_value(self, *args, **kwargs):
"""Extracts the real value to be returned from the wrapping callable.
:return: The value the double should return when called.
"""
self._called()
return self._return_value(*args, **kwargs)
def verify_arguments(self, args=None, kwargs=None):
"""Ensures that the arguments specified match the signature of the real method.
:raise: ``VerifyingDoubleError`` if the arguments do not match.
"""
args = self.args if args is None else args
kwargs = self.kwargs if kwargs is None else kwargs
try:
verify_arguments(self._target, self._method_name, args, kwargs)
except VerifyingBuiltinDoubleArgumentError:
if doubles.lifecycle.ignore_builtin_verification():
raise
@verify_count_is_non_negative
def exactly(self, n):
"""Set an exact call count allowance
:param integer n:
"""
self._call_counter.set_exact(n)
return self
@verify_count_is_non_negative
def at_least(self, n):
"""Set a minimum call count allowance
:param integer n:
"""
self._call_counter.set_minimum(n)
return self
@verify_count_is_non_negative
def at_most(self, n):
"""Set a maximum call count allowance
:param integer n:
"""
self._call_counter.set_maximum(n)
return self
def never(self):
"""Set an expected call count allowance of 0"""
self.exactly(0)
return self
def once(self):
"""Set an expected call count allowance of 1"""
self.exactly(1)
return self
def twice(self):
"""Set an expected call count allowance of 2"""
self.exactly(2)
return self
@property
def times(self):
return self
time = times
def _called(self):
"""Indicate that the allowance was called
:raise MockExpectationError if the allowance has been called too many times
"""
if self._call_counter.called().has_too_many_calls():
self.raise_failure_exception()
def raise_failure_exception(self, expect_or_allow='Allowed'):
"""Raises a ``MockExpectationError`` with a useful message.
:raise: ``MockExpectationError``
"""
raise MockExpectationError(
"{} '{}' to be called {}on {!r} with {}, but was not. ({}:{})".
format(
expect_or_allow,
self._method_name,
self._call_counter.error_string(),
self._target.obj,
self._expected_argument_string(),
self._caller.filename,
self._caller.lineno,
))
def _expected_argument_string(self):
"""Generates a string describing what arguments the double expected.
:return: A string describing expected arguments.
:rtype: str
"""
if self.args is _any and self.kwargs is _any:
return 'any args'
else:
return build_argument_repr_string(self.args, self.kwargs)
class Allowance(object):
"""An individual method allowance (stub)."""
def __init__(self, target, method_name, caller):
"""
:param Target target: The object owning the method to stub.
:param str method_name: The name of the method to stub.
"""
self._target = target
self._method_name = method_name
self._caller = caller
self.args = _any
self.kwargs = _any
self._custom_matcher = None
self._is_satisfied = True
self._call_counter = CallCountAccumulator()
self._return_value = lambda *args, **kwargs: None
def and_raise(self, exception):
"""Causes the double to raise the provided exception when called.
:param Exception exception: The exception to raise.
"""
def proxy_exception(*args, **kwargs):
raise exception
self._return_value = proxy_exception
return self
def and_raise_future(self, exception):
"""Similar to `and_raise` but the doubled method returns a future.
:param Exception exception: The exception to raise.
"""
future = _get_future()
future.set_exception(exception)
return self.and_return(future)
def and_return_future(self, *return_values):
"""Similar to `and_return` but the doubled method returns a future.
:param object return_values: The values the double will return when called,
"""
futures = []
for value in return_values:
future = _get_future()
future.set_result(value)
futures.append(future)
return self.and_return(*futures)
def and_return(self, *return_values):
"""Set a return value for an allowance
Causes the double to return the provided values in order. If multiple
values are provided, they are returned one at a time in sequence as the double is called.
If the double is called more times than there are return values, it should continue to
return the last value in the list.
:param object return_values: The values the double will return when called,
"""
if not return_values:
raise TypeError('and_return() expected at least 1 return value')
return_values = list(return_values)
final_value = return_values.pop()
self.and_return_result_of(
lambda: return_values.pop(0) if return_values else final_value
)
return self
def and_return_result_of(self, return_value):
""" Causes the double to return the result of calling the provided value.
:param return_value: A callable that will be invoked to determine the double's return value.
:type return_value: any callable object
"""
if not check_func_takes_args(return_value):
self._return_value = lambda *args, **kwargs: return_value()
else:
self._return_value = return_value
return self
def is_satisfied(self):
"""Returns a boolean indicating whether or not the double has been satisfied.
Stubs are always satisfied, but mocks are only satisifed if they've been
called as was declared.
:return: Whether or not the double is satisfied.
:rtype: bool
"""
return self._is_satisfied
def with_args(self, *args, **kwargs):
"""Declares that the double can only be called with the provided arguments.
:param args: Any positional arguments required for invocation.
:param kwargs: Any keyword arguments required for invocation.
"""
self.args = args
self.kwargs = kwargs
self.verify_arguments()
return self
def with_args_validator(self, matching_function):
"""Define a custom function for testing arguments
:param func matching_function: The function used to test arguments passed to the stub.
"""
self.args = None
self.kwargs = None
self._custom_matcher = matching_function
return self
def __call__(self, *args, **kwargs):
"""A short hand syntax for with_args
Allows callers to do:
allow(module).foo.with_args(1, 2)
With:
allow(module).foo(1, 2)
:param args: Any positional arguments required for invocation.
:param kwargs: Any keyword arguments required for invocation.
"""
return self.with_args(*args, **kwargs)
def with_no_args(self):
"""Declares that the double can only be called with no arguments."""
self.args = ()
self.kwargs = {}
self.verify_arguments()
return self
def satisfy_any_args_match(self):
"""Returns a boolean indicating whether or not the stub will accept arbitrary arguments.
This will be true unless the user has specified otherwise using ``with_args`` or
``with_no_args``.
:return: Whether or not the stub accepts arbitrary arguments.
:rtype: bool
"""
return self.args is _any and self.kwargs is _any
def satisfy_exact_match(self, args, kwargs):
"""Returns a boolean indicating whether or not the stub will accept the provided arguments.
:return: Whether or not the stub accepts the provided arguments.
:rtype: bool
"""
if self.args is None and self.kwargs is None:
return False
elif self.args is _any and self.kwargs is _any:
return True
elif args == self.args and kwargs == self.kwargs:
return True
elif len(args) != len(self.args) or len(kwargs) != len(self.kwargs):
return False
if not all(x == y or y == x for x, y in zip(args, self.args)):
return False
for key, value in self.kwargs.items():
if key not in kwargs:
return False
elif not (kwargs[key] == value or value == kwargs[key]):
return False
return True
def satisfy_custom_matcher(self, args, kwargs):
"""Return a boolean indicating if the args satisify the stub
:return: Whether or not the stub accepts the provided arguments.
:rtype: bool
"""
if not self._custom_matcher:
return False
try:
return self._custom_matcher(*args, **kwargs)
except Exception:
return False
def return_value(self, *args, **kwargs):
"""Extracts the real value to be returned from the wrapping callable.
:return: The value the double should return when called.
"""
self._called()
return self._return_value(*args, **kwargs)
def verify_arguments(self, args=None, kwargs=None):
"""Ensures that the arguments specified match the signature of the real method.
:raise: ``VerifyingDoubleError`` if the arguments do not match.
"""
args = self.args if args is None else args
kwargs = self.kwargs if kwargs is None else kwargs
try:
verify_arguments(self._target, self._method_name, args, kwargs)
except VerifyingBuiltinDoubleArgumentError:
if doubles.lifecycle.ignore_builtin_verification():
raise
@verify_count_is_non_negative
def exactly(self, n):
"""Set an exact call count allowance
:param integer n:
"""
self._call_counter.set_exact(n)
return self
@verify_count_is_non_negative
def at_least(self, n):
"""Set a minimum call count allowance
:param integer n:
"""
self._call_counter.set_minimum(n)
return self
@verify_count_is_non_negative
def at_most(self, n):
"""Set a maximum call count allowance
:param integer n:
"""
self._call_counter.set_maximum(n)
return self
def never(self):
"""Set an expected call count allowance of 0"""
self.exactly(0)
return self
def once(self):
"""Set an expected call count allowance of 1"""
self.exactly(1)
return self
def twice(self):
"""Set an expected call count allowance of 2"""
self.exactly(2)
return self
@property
def times(self):
return self
time = times
def _called(self):
"""Indicate that the allowance was called
:raise MockExpectationError if the allowance has been called too many times
"""
if self._call_counter.called().has_too_many_calls():
self.raise_failure_exception()
def raise_failure_exception(self, expect_or_allow='Allowed'):
"""Raises a ``MockExpectationError`` with a useful message.
:raise: ``MockExpectationError``
"""
raise MockExpectationError(
"{} '{}' to be called {}on {!r} with {}, but was not. ({}:{})".format(
expect_or_allow,
self._method_name,
self._call_counter.error_string(),
self._target.obj,
self._expected_argument_string(),
self._caller.filename,
self._caller.lineno,
)
)
def _expected_argument_string(self):
"""Generates a string describing what arguments the double expected.
:return: A string describing expected arguments.
:rtype: str
"""
if self.args is _any and self.kwargs is _any:
return 'any args'
else:
return build_argument_repr_string(self.args, self.kwargs)