name : workerreporter.py # -*- test-case-name: twisted.trial._dist.test.test_workerreporter -*- # # Copyright (c) Twisted Matrix Laboratories. # See LICENSE for details. """ Test reporter forwarding test results over trial distributed AMP commands. @since: 12.3 """ from types import TracebackType from typing import Callable, List, Optional, Sequence, Type, TypeVar from unittest import TestCase as PyUnitTestCase from attrs import Factory, define from typing import Literal from twisted.internet.defer import Deferred, maybeDeferred from twisted.protocols.amp import AMP, MAX_VALUE_LENGTH from twisted.python.failure import Failure from twisted.python.reflect import qual from twisted.trial._dist import managercommands from twisted.trial.reporter import TestResult from ..reporter import TrialFailure from .stream import chunk, stream T = TypeVar("T") async def addError( amp: AMP, testName: str, errorClass: str, error: str, frames: List[str] ) -> None: """ Send an error to the worker manager over an AMP connection. First the pieces which can be large are streamed over the connection. Then, L{managercommands.AddError} is called with the rest of the information and the stream IDs. :param amp: The connection to use. :param testName: The name (or ID) of the test the error relates to. :param errorClass: The fully qualified name of the error type. :param error: The string representation of the error. :param frames: The lines of the traceback associated with the error. """ errorStreamId = await stream(amp, chunk(error.encode("utf-8"), MAX_VALUE_LENGTH)) framesStreamId = await stream(amp, (frame.encode("utf-8") for frame in frames)) await amp.callRemote( managercommands.AddError, testName=testName, errorClass=errorClass, errorStreamId=errorStreamId, framesStreamId=framesStreamId, ) async def addFailure( amp: AMP, testName: str, fail: str, failClass: str, frames: List[str] ) -> None: """ Like L{addError} but for failures. :param amp: See L{addError} :param testName: See L{addError} :param failClass: The fully qualified name of the exception associated with the failure. :param fail: The string representation of the failure. :param frames: The lines of the traceback associated with the error. """ failStreamId = await stream(amp, chunk(fail.encode("utf-8"), MAX_VALUE_LENGTH)) framesStreamId = await stream(amp, (frame.encode("utf-8") for frame in frames)) await amp.callRemote( managercommands.AddFailure, testName=testName, failClass=failClass, failStreamId=failStreamId, framesStreamId=framesStreamId, ) async def addExpectedFailure(amp: AMP, testName: str, error: str, todo: str) -> None: """ Like L{addError} but for expected failures. :param amp: See L{addError} :param testName: See L{addError} :param error: The string representation of the expected failure. :param todo: The string description of the expectation. """ errorStreamId = await stream(amp, chunk(error.encode("utf-8"), MAX_VALUE_LENGTH)) await amp.callRemote( managercommands.AddExpectedFailure, testName=testName, errorStreamId=errorStreamId, todo=todo, ) @define class ReportingResults: """ A mutable container for the result of sending test results back to the parent process. Since it is possible for these sends to fail asynchronously but the L{TestResult} protocol is not well suited for asynchronous result reporting, results are collected on an instance of this class and when the runner believes the test is otherwise complete, it can collect the results and do something with any errors. :ivar _reporter: The L{WorkerReporter} this object is associated with. This is the object doing the result reporting. :ivar _results: A list of L{Deferred} instances representing the results of reporting operations. This is expected to grow over the course of the test run and then be inspected by the runner once the test is over. The public interface to this list is via the context manager interface. """ _reporter: "WorkerReporter" _results: List[Deferred[object]] = Factory(list) def __enter__(self) -> Sequence[Deferred[object]]: """ Begin a new reportable context in which results can be collected. :return: A sequence which will contain the L{Deferred} instances representing the results of all test result reporting that happens while the context manager is active. The sequence is extended as the test runs so its value should not be consumed until the test is over. """ return self._results def __exit__( self, excType: Type[BaseException], excValue: BaseException, excTraceback: TracebackType, ) -> Literal[False]: """ End the reportable context. """ self._reporter._reporting = None return False def record(self, result: Deferred[object]) -> None: """ Record a L{Deferred} instance representing one test result reporting operation. """ self._results.append(result) class WorkerReporter(TestResult): """ Reporter for trial's distributed workers. We send things not through a stream, but through an C{AMP} protocol's C{callRemote} method. @ivar _DEFAULT_TODO: Default message for expected failures and unexpected successes, used only if a C{Todo} is not provided. @ivar _reporting: When a "result reporting" context is active, the corresponding context manager. Otherwise, L{None}. """ _DEFAULT_TODO = "Test expected to fail" ampProtocol: AMP _reporting: Optional[ReportingResults] = None def __init__(self, ampProtocol): """ @param ampProtocol: The communication channel with the trial distributed manager which collects all test results. """ super().__init__() self.ampProtocol = ampProtocol def gatherReportingResults(self) -> ReportingResults: """ Get a "result reporting" context manager. In a "result reporting" context, asynchronous test result reporting methods may be used safely. Their results (in particular, failures) are available from the context manager. """ self._reporting = ReportingResults(self) return self._reporting def _getFailure(self, error: TrialFailure) -> Failure: """ Convert a C{sys.exc_info()}-style tuple to a L{Failure}, if necessary. """ if isinstance(error, tuple): return Failure(error[1], error[0], error[2]) return error def _getFrames(self, failure: Failure) -> List[str]: """ Extract frames from a C{Failure} instance. """ frames: List[str] = [] for frame in failure.frames: # The code object's name, the code object's filename, and the line # number. frames.extend([frame[0], frame[1], str(frame[2])]) return frames def _call(self, f: Callable[[], T]) -> None: """ Call L{f} if and only if a "result reporting" context is active. @param f: A function to call. Its result is accumulated into the result reporting context. It may return a L{Deferred} or a coroutine or synchronously raise an exception or return a result value. @raise ValueError: If no result reporting context is active. """ if self._reporting is not None: self._reporting.record(maybeDeferred(f)) else: raise ValueError( "Cannot call command outside of reporting context manager." ) def addSuccess(self, test: PyUnitTestCase) -> None: """ Send a success to the parent process. This must be called in context managed by L{gatherReportingResults}. """ super().addSuccess(test) testName = test.id() self._call( lambda: self.ampProtocol.callRemote( managercommands.AddSuccess, testName=testName ) ) async def addErrorFallible(self, testName: str, errorObj: TrialFailure) -> None: """ Attempt to report an error to the parent process. Unlike L{addError} this can fail asynchronously. This version is for infrastructure code that can apply its own failure handling. @return: A L{Deferred} that fires with the result of the attempt. """ failure = self._getFailure(errorObj) errorStr = failure.getErrorMessage() errorClass = qual(failure.type) frames = self._getFrames(failure) await addError( self.ampProtocol, testName, errorClass, errorStr, frames, ) def addError(self, test: PyUnitTestCase, error: TrialFailure) -> None: """ Send an error to the parent process. """ super().addError(test, error) testName = test.id() self._call(lambda: self.addErrorFallible(testName, error)) def addFailure(self, test: PyUnitTestCase, fail: TrialFailure) -> None: """ Send a Failure over. """ super().addFailure(test, fail) testName = test.id() failure = self._getFailure(fail) failureMessage = failure.getErrorMessage() failClass = qual(failure.type) frames = self._getFrames(failure) self._call( lambda: addFailure( self.ampProtocol, testName, failureMessage, failClass, frames, ), ) def addSkip(self, test, reason): """ Send a skip over. """ super().addSkip(test, reason) reason = str(reason) testName = test.id() self._call( lambda: self.ampProtocol.callRemote( managercommands.AddSkip, testName=testName, reason=reason ) ) def _getTodoReason(self, todo): """ Get the reason for a C{Todo}. If C{todo} is L{None}, return a sensible default. """ if todo is None: return self._DEFAULT_TODO else: return todo.reason def addExpectedFailure(self, test, error, todo=None): """ Send an expected failure over. """ super().addExpectedFailure(test, error, todo) errorMessage = error.getErrorMessage() testName = test.id() self._call( lambda: addExpectedFailure( self.ampProtocol, testName=testName, error=errorMessage, todo=self._getTodoReason(todo), ) ) def addUnexpectedSuccess(self, test, todo=None): """ Send an unexpected success over. """ super().addUnexpectedSuccess(test, todo) testName = test.id() self._call( lambda: self.ampProtocol.callRemote( managercommands.AddUnexpectedSuccess, testName=testName, todo=self._getTodoReason(todo), ) ) def printSummary(self): """ I{Don't} print a summary """