Source code for ophyd_async.core._mock_signal_utils
from contextlib import asynccontextmanager, contextmanager
from typing import Any, Awaitable, Callable, Iterable
from unittest.mock import AsyncMock
from ._mock_signal_backend import MockSignalBackend
from ._signal import Signal
from ._utils import T
def _get_mock_signal_backend(signal: Signal) -> MockSignalBackend:
backend = signal._backend # noqa:SLF001
assert isinstance(backend, MockSignalBackend), (
"Expected to receive a `MockSignalBackend`, instead "
f" received {type(backend)}. "
)
return backend
[docs]
def set_mock_value(signal: Signal[T], value: T):
"""Set the value of a signal that is in mock mode."""
backend = _get_mock_signal_backend(signal)
backend.set_value(value)
[docs]
def set_mock_put_proceeds(signal: Signal, proceeds: bool):
"""Allow or block a put with wait=True from proceeding"""
backend = _get_mock_signal_backend(signal)
if proceeds:
backend.put_proceeds.set()
else:
backend.put_proceeds.clear()
[docs]
@asynccontextmanager
async def mock_puts_blocked(*signals: Signal):
for signal in signals:
set_mock_put_proceeds(signal, False)
yield
for signal in signals:
set_mock_put_proceeds(signal, True)
[docs]
def get_mock_put(signal: Signal) -> AsyncMock:
"""Get the mock associated with the put call on the signal."""
return _get_mock_signal_backend(signal).put_mock
[docs]
def reset_mock_put_calls(signal: Signal):
backend = _get_mock_signal_backend(signal)
backend.put_mock.reset_mock()
class _SetValuesIterator:
# Garbage collected by the time __del__ is called unless we put it as a
# global attrbute here.
require_all_consumed: bool = False
def __init__(
self,
signal: Signal,
values: Iterable[Any],
require_all_consumed: bool = False,
):
self.signal = signal
self.values = values
self.require_all_consumed = require_all_consumed
self.index = 0
self.iterator = enumerate(values, start=1)
def __iter__(self):
return self
def __next__(self):
# Will propogate StopIteration
self.index, next_value = next(self.iterator)
set_mock_value(self.signal, next_value)
return next_value
def __del__(self):
if self.require_all_consumed:
# Values is cast to a list here because the user has supplied
# require_all_consumed=True, we can therefore assume they
# supplied a finite list.
# In the case of require_all_consumed=False, an infinite
# iterble is permitted
values = list(self.values)
if self.index != len(values):
# Report the values consumed and the values yet to be
# consumed
consumed = values[0 : self.index]
to_be_consumed = values[self.index :]
raise AssertionError(
f"{self.signal.name}: {consumed} were consumed "
f"but {to_be_consumed} were not consumed"
)
[docs]
def set_mock_values(
signal: Signal,
values: Iterable[Any],
require_all_consumed: bool = False,
) -> _SetValuesIterator:
"""Iterator to set a signal to a sequence of values, optionally repeating the
sequence.
Parameters
----------
signal:
A signal with a `MockSignalBackend` backend.
values:
An iterable of the values to set the signal to, on each iteration
the value will be set.
require_all_consumed:
If True, an AssertionError will be raised if the iterator is deleted before
all values have been consumed.
Notes
-----
Example usage::
for value_set in set_mock_values(signal, [1, 2, 3]):
# do something
cm = set_mock_values(signal, 1, 2, 3, require_all_consumed=True):
next(cm)
# do something
"""
return _SetValuesIterator(
signal,
values,
require_all_consumed=require_all_consumed,
)
@contextmanager
def _unset_side_effect_cm(put_mock: AsyncMock):
yield
put_mock.side_effect = None
[docs]
def callback_on_mock_put(
signal: Signal[T], callback: Callable[[T], None] | Callable[[T], Awaitable[None]]
):
"""For setting a callback when a backend is put to.
Can either be used in a context, with the callback being
unset on exit, or as an ordinary function.
Parameters
----------
signal:
A signal with a `MockSignalBackend` backend.
callback:
The callback to call when the backend is put to during the context.
"""
backend = _get_mock_signal_backend(signal)
backend.put_mock.side_effect = callback
return _unset_side_effect_cm(backend.put_mock)