src/twisted/test/test_rebuild.py

# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.


import sys, os
import types

from twisted.trial import unittest
from twisted.python import rebuild
from twisted.python.compat import _PY3

from . import crash_test_dummy
f = crash_test_dummy.foo

class Foo: pass
class Bar(Foo): pass
class Baz(object): pass
class Buz(Bar, Baz): pass

class HashRaisesRuntimeError:
    """
    Things that don't hash (raise an Exception) should be ignored by the
    rebuilder.

    @ivar hashCalled: C{bool} set to True when __hash__ is called.
    """
    def __init__(self):
        self.hashCalled = False


    def __hash__(self):
        self.hashCalled = True
        raise RuntimeError('not a TypeError!')


# Set in test_hashException
unhashableObject = None


class RebuildTests(unittest.TestCase):
    """
    Simple testcase for rebuilding, to at least exercise the code.
    """
    def setUp(self):
        self.libPath = self.mktemp()
        os.mkdir(self.libPath)
        self.fakelibPath = os.path.join(self.libPath,
                                        'twisted_rebuild_fakelib')
        os.mkdir(self.fakelibPath)
        open(os.path.join(self.fakelibPath, '__init__.py'), 'w').close()
        sys.path.insert(0, self.libPath)


    def tearDown(self):
        sys.path.remove(self.libPath)


    def test_FileRebuild(self):
        from twisted.python.util import sibpath
        import shutil, time
        shutil.copyfile(sibpath(__file__, "myrebuilder1.py"),
                        os.path.join(self.fakelibPath, "myrebuilder.py"))
        from twisted_rebuild_fakelib import myrebuilder
        a = myrebuilder.A()
        b = myrebuilder.B()
        i = myrebuilder.Inherit()
        self.assertEqual(a.a(), 'a')
        # Necessary because the file has not "changed" if a second has not gone
        # by in unix.  This sucks, but it's not often that you'll be doing more
        # than one reload per second.
        time.sleep(1.1)
        shutil.copyfile(sibpath(__file__, "myrebuilder2.py"),
                        os.path.join(self.fakelibPath, "myrebuilder.py"))
        rebuild.rebuild(myrebuilder)
        b2 = myrebuilder.B()
        self.assertEqual(b2.b(), 'c')
        self.assertEqual(b.b(), 'c')
        self.assertEqual(i.a(), 'd')
        self.assertEqual(a.a(), 'b')


    def test_Rebuild(self):
        """
        Rebuilding an unchanged module.
        """
        # This test would actually pass if rebuild was a no-op, but it
        # ensures rebuild doesn't break stuff while being a less
        # complex test than testFileRebuild.

        x = crash_test_dummy.X('a')

        rebuild.rebuild(crash_test_dummy, doLog=False)
        # Instance rebuilding is triggered by attribute access.
        x.do()
        self.assertEqual(x.__class__, crash_test_dummy.X)

        self.assertEqual(f, crash_test_dummy.foo)


    def test_ComponentInteraction(self):
        x = crash_test_dummy.XComponent()
        x.setAdapter(crash_test_dummy.IX, crash_test_dummy.XA)
        x.getComponent(crash_test_dummy.IX)
        rebuild.rebuild(crash_test_dummy, 0)
        newComponent = x.getComponent(crash_test_dummy.IX)

        newComponent.method()

        self.assertEqual(newComponent.__class__, crash_test_dummy.XA)

        # Test that a duplicate registerAdapter is not allowed
        from twisted.python import components
        self.assertRaises(ValueError, components.registerAdapter,
                              crash_test_dummy.XA, crash_test_dummy.X,
                              crash_test_dummy.IX)


    def test_UpdateInstance(self):
        global Foo, Buz

        b = Buz()

        class Foo:
            def foo(self):
                """
                Dummy method
                """

        class Buz(Bar, Baz):
            x = 10

        rebuild.updateInstance(b)
        assert hasattr(b, 'foo'), "Missing method on rebuilt instance"
        assert hasattr(b, 'x'), "Missing class attribute on rebuilt instance"


    def test_BananaInteraction(self):
        from twisted.python import rebuild
        from twisted.spread import banana
        rebuild.latestClass(banana.Banana)


    def test_hashException(self):
        """
        Rebuilding something that has a __hash__ that raises a non-TypeError
        shouldn't cause rebuild to die.
        """
        global unhashableObject
        unhashableObject = HashRaisesRuntimeError()
        def _cleanup():
            global unhashableObject
            unhashableObject = None
        self.addCleanup(_cleanup)
        rebuild.rebuild(rebuild)
        self.assertTrue(unhashableObject.hashCalled)


    def test_Sensitive(self):
        """
        L{twisted.python.rebuild.Sensitive}
        """
        from twisted.python import rebuild
        from twisted.python.rebuild import Sensitive

        class TestSensitive(Sensitive):
            def test_method(self):
                """
                Dummy method
                """

        testSensitive = TestSensitive()
        testSensitive.rebuildUpToDate()
        self.assertFalse(testSensitive.needRebuildUpdate())

        # Test rebuilding a builtin class
        newException = rebuild.latestClass(Exception)
        if _PY3:
            self.assertEqual(repr(Exception), repr(newException))
        else:
            self.assertIn('twisted.python.rebuild.Exception', repr(newException))
        self.assertEqual(newException, testSensitive.latestVersionOf(newException))

        # Test types.MethodType on method in class
        self.assertEqual(TestSensitive.test_method,
            testSensitive.latestVersionOf(TestSensitive.test_method))
        # Test types.MethodType on method in instance of class
        self.assertEqual(testSensitive.test_method,
            testSensitive.latestVersionOf(testSensitive.test_method))
        # Test a class
        self.assertEqual(TestSensitive,
            testSensitive.latestVersionOf(TestSensitive))

        class Foo:
            """
            Dummy class
            """

        foo = Foo()

        # Test types.InstanceType
        self.assertEqual(foo, testSensitive.latestVersionOf(foo))

        def myFunction():
            """
            Dummy method
            """

        # Test types.FunctionType
        self.assertEqual(myFunction, testSensitive.latestVersionOf(myFunction))


class NewStyleTests(unittest.TestCase):
    """
    Tests for rebuilding new-style classes of various sorts.
    """
    def setUp(self):
        self.m = types.ModuleType('whipping')
        sys.modules['whipping'] = self.m


    def tearDown(self):
        del sys.modules['whipping']
        del self.m


    def test_slots(self):
        """
        Try to rebuild a new style class with slots defined.
        """
        classDefinition = (
            "class SlottedClass(object):\n"
            "    __slots__ = ['a']\n")

        exec(classDefinition, self.m.__dict__)
        inst = self.m.SlottedClass()
        inst.a = 7
        exec(classDefinition, self.m.__dict__)
        rebuild.updateInstance(inst)
        self.assertEqual(inst.a, 7)
        self.assertIs(type(inst), self.m.SlottedClass)


    def test_typeSubclass(self):
        """
        Try to rebuild a base type subclass.
        """
        classDefinition = (
            "class ListSubclass(list):\n"
            "    pass\n")

        exec(classDefinition, self.m.__dict__)
        inst = self.m.ListSubclass()
        inst.append(2)
        exec(classDefinition, self.m.__dict__)
        rebuild.updateInstance(inst)
        self.assertEqual(inst[0], 2)
        self.assertIs(type(inst), self.m.ListSubclass)


    def test_instanceSlots(self):
        """
        Test that when rebuilding an instance with a __slots__ attribute, it
        fails accurately instead of giving a L{rebuild.RebuildError}.
        """
        classDefinition = (
            "class NotSlottedClass(object):\n"
            "    pass\n")

        exec(classDefinition, self.m.__dict__)
        inst = self.m.NotSlottedClass()
        inst.__slots__ = ['a']
        classDefinition = (
            "class NotSlottedClass:\n"
            "    pass\n")
        exec(classDefinition, self.m.__dict__)
        # Moving from new-style class to old-style should fail.
        self.assertRaises(TypeError, rebuild.updateInstance, inst)

    if getattr(types, 'ClassType', None) is None:
        test_instanceSlots.skip = "Old-style classes not supported on Python 3"