RAHHH

backend/lib/python3.12/site-packages/twisted/application/test/test_service.py

@@ -0,0 +1,175 @@
+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+"""
+Tests for L{twisted.application.service}.
+"""
+
+
+from zope.interface import implementer
+from zope.interface.exceptions import BrokenImplementation
+from zope.interface.verify import verifyObject
+
+from twisted.application.service import (
+    Application,
+    IProcess,
+    IService,
+    IServiceCollection,
+    Service,
+)
+from twisted.persisted.sob import IPersistable
+from twisted.trial.unittest import TestCase
+
+
+@implementer(IService)
+class AlmostService:
+    """
+    Implement IService in a way that can fail.
+
+    In general, classes should maintain invariants that adhere
+    to the interfaces that they claim to implement --
+    otherwise, it is a bug.
+
+    This is a buggy class -- the IService implementation is fragile,
+    and several methods will break it. These bugs are intentional,
+    as the tests trigger them -- and then check that the class,
+    indeed, no longer complies with the interface (IService)
+    that it claims to comply with.
+
+    Since the verification will, by definition, only fail on buggy classes --
+    in other words, those which do not actually support the interface they
+    claim to support, we have to write a buggy class to properly verify
+    the interface.
+    """
+
+    def __init__(self, name: str, parent: IServiceCollection, running: bool) -> None:
+        self.name = name
+        self.parent = parent
+        self.running = running
+
+    def makeInvalidByDeletingName(self) -> None:
+        """
+        Probably not a wise method to call.
+
+        This method removes the :code:`name` attribute,
+        which has to exist in IService classes.
+        """
+        del self.name
+
+    def makeInvalidByDeletingParent(self) -> None:
+        """
+        Probably not a wise method to call.
+
+        This method removes the :code:`parent` attribute,
+        which has to exist in IService classes.
+        """
+        del self.parent
+
+    def makeInvalidByDeletingRunning(self) -> None:
+        """
+        Probably not a wise method to call.
+
+        This method removes the :code:`running` attribute,
+        which has to exist in IService classes.
+        """
+        del self.running
+
+    def setName(self, name: object) -> None:
+        """
+        See L{twisted.application.service.IService}.
+
+        @param name: ignored
+        """
+
+    def setServiceParent(self, parent: object) -> None:
+        """
+        See L{twisted.application.service.IService}.
+
+        @param parent: ignored
+        """
+
+    def disownServiceParent(self) -> None:
+        """
+        See L{twisted.application.service.IService}.
+        """
+
+    def privilegedStartService(self) -> None:
+        """
+        See L{twisted.application.service.IService}.
+        """
+
+    def startService(self) -> None:
+        """
+        See L{twisted.application.service.IService}.
+        """
+
+    def stopService(self) -> None:
+        """
+        See L{twisted.application.service.IService}.
+        """
+
+
+class ServiceInterfaceTests(TestCase):
+    """
+    Tests for L{twisted.application.service.IService} implementation.
+    """
+
+    def setUp(self) -> None:
+        """
+        Build something that implements IService.
+        """
+        self.almostService = AlmostService(parent=None, running=False, name=None)  # type: ignore[arg-type]
+
+    def test_realService(self) -> None:
+        """
+        Service implements IService.
+        """
+        myService = Service()
+        verifyObject(IService, myService)
+
+    def test_hasAll(self) -> None:
+        """
+        AlmostService implements IService.
+        """
+        verifyObject(IService, self.almostService)
+
+    def test_noName(self) -> None:
+        """
+        AlmostService with no name does not implement IService.
+        """
+        self.almostService.makeInvalidByDeletingName()
+        with self.assertRaises(BrokenImplementation):
+            verifyObject(IService, self.almostService)
+
+    def test_noParent(self) -> None:
+        """
+        AlmostService with no parent does not implement IService.
+        """
+        self.almostService.makeInvalidByDeletingParent()
+        with self.assertRaises(BrokenImplementation):
+            verifyObject(IService, self.almostService)
+
+    def test_noRunning(self) -> None:
+        """
+        AlmostService with no running does not implement IService.
+        """
+        self.almostService.makeInvalidByDeletingRunning()
+        with self.assertRaises(BrokenImplementation):
+            verifyObject(IService, self.almostService)
+
+
+class ApplicationTests(TestCase):
+    """
+    Tests for L{twisted.application.service.Application}.
+    """
+
+    def test_applicationComponents(self) -> None:
+        """
+        Check L{twisted.application.service.Application} instantiation.
+        """
+        app = Application("app-name")
+
+        self.assertTrue(verifyObject(IService, IService(app)))
+        self.assertTrue(verifyObject(IServiceCollection, IServiceCollection(app)))
+        self.assertTrue(verifyObject(IProcess, IProcess(app)))
+        self.assertTrue(verifyObject(IPersistable, IPersistable(app)))