Ausgabe der neuen DB Einträge

venv/lib/python3.9/site-packages/twisted/test/test_defgen.py

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+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+"""
+Tests for L{twisted.internet.defer.deferredGenerator} and related APIs.
+"""
+
+from __future__ import division, absolute_import
+
+from twisted.internet import reactor
+
+from twisted.trial import unittest
+
+from twisted.internet.defer import waitForDeferred, deferredGenerator, Deferred
+from twisted.internet.defer import inlineCallbacks, returnValue
+from twisted.internet import defer
+from twisted.trial.util import suppress as SUPPRESS
+from twisted.python.util import runWithWarningsSuppressed
+
+
+def getThing():
+    d = Deferred()
+    reactor.callLater(0, d.callback, "hi")
+    return d
+
+def getOwie():
+    d = Deferred()
+    def CRAP():
+        d.errback(ZeroDivisionError('OMG'))
+    reactor.callLater(0, CRAP)
+    return d
+
+# NOTE: most of the tests in DeferredGeneratorTests are duplicated
+# with slightly different syntax for the InlineCallbacksTests below.
+
+class TerminalException(Exception):
+    pass
+
+class BaseDefgenTests:
+    """
+    This class sets up a bunch of test cases which will test both
+    deferredGenerator and inlineCallbacks based generators. The subclasses
+    DeferredGeneratorTests and InlineCallbacksTests each provide the actual
+    generator implementations tested.
+    """
+
+    def testBasics(self):
+        """
+        Test that a normal deferredGenerator works.  Tests yielding a
+        deferred which callbacks, as well as a deferred errbacks. Also
+        ensures returning a final value works.
+        """
+
+        return self._genBasics().addCallback(self.assertEqual, 'WOOSH')
+
+    def testBuggy(self):
+        """
+        Ensure that a buggy generator properly signals a Failure
+        condition on result deferred.
+        """
+        return self.assertFailure(self._genBuggy(), ZeroDivisionError)
+
+    def testNothing(self):
+        """Test that a generator which never yields results in None."""
+
+        return self._genNothing().addCallback(self.assertEqual, None)
+
+    def testHandledTerminalFailure(self):
+        """
+        Create a Deferred Generator which yields a Deferred which fails and
+        handles the exception which results.  Assert that the Deferred
+        Generator does not errback its Deferred.
+        """
+        return self._genHandledTerminalFailure().addCallback(self.assertEqual, None)
+
+    def testHandledTerminalAsyncFailure(self):
+        """
+        Just like testHandledTerminalFailure, only with a Deferred which fires
+        asynchronously with an error.
+        """
+        d = defer.Deferred()
+        deferredGeneratorResultDeferred = self._genHandledTerminalAsyncFailure(d)
+        d.errback(TerminalException("Handled Terminal Failure"))
+        return deferredGeneratorResultDeferred.addCallback(
+            self.assertEqual, None)
+
+    def testStackUsage(self):
+        """
+        Make sure we don't blow the stack when yielding immediately
+        available deferreds.
+        """
+        return self._genStackUsage().addCallback(self.assertEqual, 0)
+
+    def testStackUsage2(self):
+        """
+        Make sure we don't blow the stack when yielding immediately
+        available values.
+        """
+        return self._genStackUsage2().addCallback(self.assertEqual, 0)
+
+
+
+def deprecatedDeferredGenerator(f):
+    """
+    Calls L{deferredGenerator} while suppressing the deprecation warning.
+
+    @param f: Function to call
+    @return: Return value of function.
+    """
+    return runWithWarningsSuppressed(
+        [ SUPPRESS(message="twisted.internet.defer.deferredGenerator was "
+                          "deprecated") ],
+        deferredGenerator, f)
+
+
+
+class DeferredGeneratorTests(BaseDefgenTests, unittest.TestCase):
+
+    # First provide all the generator impls necessary for BaseDefgenTests
+    @deprecatedDeferredGenerator
+    def _genBasics(self):
+
+        x = waitForDeferred(getThing())
+        yield x
+        x = x.getResult()
+
+        self.assertEqual(x, "hi")
+
+        ow = waitForDeferred(getOwie())
+        yield ow
+        try:
+            ow.getResult()
+        except ZeroDivisionError as e:
+            self.assertEqual(str(e), 'OMG')
+        yield "WOOSH"
+        return
+
+
+    @deprecatedDeferredGenerator
+    def _genBuggy(self):
+        yield waitForDeferred(getThing())
+        1//0
+
+
+    @deprecatedDeferredGenerator
+    def _genNothing(self):
+        if 0: yield 1
+
+
+    @deprecatedDeferredGenerator
+    def _genHandledTerminalFailure(self):
+        x = waitForDeferred(defer.fail(TerminalException("Handled Terminal Failure")))
+        yield x
+        try:
+            x.getResult()
+        except TerminalException:
+            pass
+
+
+    @deprecatedDeferredGenerator
+    def _genHandledTerminalAsyncFailure(self, d):
+        x = waitForDeferred(d)
+        yield x
+        try:
+            x.getResult()
+        except TerminalException:
+            pass
+
+
+    def _genStackUsage(self):
+        for x in range(5000):
+            # Test with yielding a deferred
+            x = waitForDeferred(defer.succeed(1))
+            yield x
+            x = x.getResult()
+        yield 0
+    _genStackUsage = deprecatedDeferredGenerator(_genStackUsage)
+
+    def _genStackUsage2(self):
+        for x in range(5000):
+            # Test with yielding a random value
+            yield 1
+        yield 0
+    _genStackUsage2 = deprecatedDeferredGenerator(_genStackUsage2)
+
+    # Tests unique to deferredGenerator
+
+    def testDeferredYielding(self):
+        """
+        Ensure that yielding a Deferred directly is trapped as an
+        error.
+        """
+        # See the comment _deferGenerator about d.callback(Deferred).
+        def _genDeferred():
+            yield getThing()
+        _genDeferred = deprecatedDeferredGenerator(_genDeferred)
+
+        return self.assertFailure(_genDeferred(), TypeError)
+
+    suppress = [
+            SUPPRESS(message='twisted.internet.defer.waitForDeferred was '
+                             'deprecated')
+            ]
+
+class InlineCallbacksTests(BaseDefgenTests, unittest.TestCase):
+    # First provide all the generator impls necessary for BaseDefgenTests
+
+    def _genBasics(self):
+
+        x = yield getThing()
+
+        self.assertEqual(x, "hi")
+
+        try:
+            yield getOwie()
+        except ZeroDivisionError as e:
+            self.assertEqual(str(e), 'OMG')
+        returnValue("WOOSH")
+    _genBasics = inlineCallbacks(_genBasics)
+
+    def _genBuggy(self):
+        yield getThing()
+        1/0
+    _genBuggy = inlineCallbacks(_genBuggy)
+
+
+    def _genNothing(self):
+        if 0: yield 1
+    _genNothing = inlineCallbacks(_genNothing)
+
+
+    def _genHandledTerminalFailure(self):
+        try:
+            yield defer.fail(TerminalException("Handled Terminal Failure"))
+        except TerminalException:
+            pass
+    _genHandledTerminalFailure = inlineCallbacks(_genHandledTerminalFailure)
+
+
+    def _genHandledTerminalAsyncFailure(self, d):
+        try:
+            yield d
+        except TerminalException:
+            pass
+    _genHandledTerminalAsyncFailure = inlineCallbacks(
+        _genHandledTerminalAsyncFailure)
+
+
+    def _genStackUsage(self):
+        for x in range(5000):
+            # Test with yielding a deferred
+            yield defer.succeed(1)
+        returnValue(0)
+    _genStackUsage = inlineCallbacks(_genStackUsage)
+
+    def _genStackUsage2(self):
+        for x in range(5000):
+            # Test with yielding a random value
+            yield 1
+        returnValue(0)
+    _genStackUsage2 = inlineCallbacks(_genStackUsage2)
+
+    # Tests unique to inlineCallbacks
+
+    def testYieldNonDeferred(self):
+        """
+        Ensure that yielding a non-deferred passes it back as the
+        result of the yield expression.
+
+        @return: A L{twisted.internet.defer.Deferred}
+        @rtype: L{twisted.internet.defer.Deferred}
+        """
+        def _test():
+            yield 5
+            returnValue(5)
+        _test = inlineCallbacks(_test)
+
+        return _test().addCallback(self.assertEqual, 5)
+
+    def testReturnNoValue(self):
+        """Ensure a standard python return results in a None result."""
+        def _noReturn():
+            yield 5
+            return
+        _noReturn = inlineCallbacks(_noReturn)
+
+        return _noReturn().addCallback(self.assertEqual, None)
+
+    def testReturnValue(self):
+        """Ensure that returnValue works."""
+        def _return():
+            yield 5
+            returnValue(6)
+        _return = inlineCallbacks(_return)
+
+        return _return().addCallback(self.assertEqual, 6)
+
+
+    def test_nonGeneratorReturn(self):
+        """
+        Ensure that C{TypeError} with a message about L{inlineCallbacks} is
+        raised when a non-generator returns something other than a generator.
+        """
+        def _noYield():
+            return 5
+        _noYield = inlineCallbacks(_noYield)
+
+        self.assertIn("inlineCallbacks",
+            str(self.assertRaises(TypeError, _noYield)))
+
+
+    def test_nonGeneratorReturnValue(self):
+        """
+        Ensure that C{TypeError} with a message about L{inlineCallbacks} is
+        raised when a non-generator calls L{returnValue}.
+        """
+        def _noYield():
+            returnValue(5)
+        _noYield = inlineCallbacks(_noYield)
+
+        self.assertIn("inlineCallbacks",
+            str(self.assertRaises(TypeError, _noYield)))
+
+
+
+class DeprecateDeferredGeneratorTests(unittest.SynchronousTestCase):
+    """
+    Tests that L{DeferredGeneratorTests} and L{waitForDeferred} are
+    deprecated.
+    """
+
+    def test_deferredGeneratorDeprecated(self):
+        """
+        L{deferredGenerator} is deprecated.
+        """
+        @deferredGenerator
+        def decoratedFunction():
+            yield None
+
+        warnings = self.flushWarnings([self.test_deferredGeneratorDeprecated])
+        self.assertEqual(len(warnings), 1)
+        self.assertEqual(warnings[0]['category'], DeprecationWarning)
+        self.assertEqual(
+            warnings[0]['message'],
+            "twisted.internet.defer.deferredGenerator was deprecated in "
+            "Twisted 15.0.0; please use "
+            "twisted.internet.defer.inlineCallbacks instead")
+
+    def test_waitForDeferredDeprecated(self):
+        """
+        L{waitForDeferred} is deprecated.
+        """
+        d = Deferred()
+        waitForDeferred(d)
+
+        warnings = self.flushWarnings([self.test_waitForDeferredDeprecated])
+        self.assertEqual(len(warnings), 1)
+        self.assertEqual(warnings[0]['category'], DeprecationWarning)
+        self.assertEqual(
+            warnings[0]['message'],
+            "twisted.internet.defer.waitForDeferred was deprecated in "
+            "Twisted 15.0.0; please use "
+            "twisted.internet.defer.inlineCallbacks instead")