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Testing utilities to detect which handlers were called #103
Description
Description
There is a TraceableBus for seeing which messages are passed to a bus, but nothing currently to inspect which handlers were called.
Motivation
Some folk might want to write automated tests to ensure that the correct handler was called for a message.
Possible implementation
Something along the lines of the following, where filename, function, lineno, and timestamp function similarly to the MessageInfo in TraceableBus and reference, handler, name, and request relate to the called handler.
@dataclasses.dataclass(frozen=True)
class HandlerInfo[T]:
#: handler reference instance
reference: HandlerReference[T]
#: handler object
handler: Handler[T]
#: module path and class or function name of the handler
name: str
#: request object
request: T
#: filename where call originated
filename: str
#: function where call originated
function: str
#: line in file where call originated
lineno: int
#: timestamp of call
timestamp: datetime.datetime
class TraceableHandlerFactory(banshee.HandlerFactory):
def __init__(self, factory: banshee.HandlerFactory) -> None:
self.factory = factory
self._handlers = []
@property
def handlers(self):
return tuple(self._handlers)
def __call__(self, reference: banshee.HandlerReference[T], /) -> banshee.Handler[T]:
handler = self.factory(reference)
@functools.wrap(handler)
def wrapper(request: T) -> typing.Any:
self._handlers.append(HandlerInfo(...))
return handler(request)
return wrapperthen in a test something like the following can be used:
factory = banshee.SimpleHandlerFactory()
traceable_factory = banshee.TraceableHandlerFactory(factory)
bus = (
banshee.Builder()
.with_factory(traceable_factory)
request = FooCommand()
bus.handle(request)
assert any(
(info.name == "myapp.handlers.handle_foo" and request == request)
for info in traceable_bus.handlers
)Reacted by Gustavo Albino
Activity
[-]feat: testing utilities to detect which handlers were called[/-][+]Testing utilities to detect which handlers were called[/+]