[Zope3-checkins] CVS: Zope/lib/python/persistent/tests - persistent.txt:1.1 test_persistent.py:1.3

Jeremy Hylton jeremy at zope.com
Tue Mar 2 17:15:15 EST 2004


Update of /cvs-repository/Zope/lib/python/persistent/tests
In directory cvs.zope.org:/tmp/cvs-serv11278/tests

Modified Files:
	test_persistent.py 
Added Files:
	persistent.txt 
Log Message:
Convert unittest tests into a single doctest file.

I've included some code to convert a text file containing doctest
tests into a unittest.TestCase.  This code wants to be generic, but
I'm not sure if it's simple enough yet.


=== Added File Zope/lib/python/persistent/tests/persistent.txt ===
Tests for persistent.Persistent
===============================

This document is an extended doc test that covers the basics of the
Persistent base class.  It depends on a few base classes defined in
test_persistent.py.

Test Persistent without Data Manager
------------------------------------

First do some simple tests of a Persistent instance that does not have
a data manager (_p_jar).

>>> p = P()
>>> p.x
0
>>> p._p_changed
False
>>> p._p_state
0
>>> p._p_jar
>>> p._p_oid

Verify that modifications have no effect on _p_state of _p_changed.

>>> p.inc()
>>> p.inc()
>>> p.x
2
>>> p._p_changed
False
>>> p._p_state
0

Try all sorts of different ways to change the object's state.

>>> p._p_deactivate()
>>> p._p_state
0
>>> p._p_changed = True
>>> p._p_state
0
>>> del p._p_changed
>>> p._p_changed
False
>>> p._p_state
0
>>> p.x
2

Test Persistent with Data Manager
---------------------------------

Next try some tests of an object with a data manager.  The DM class is
a simple testing stub.
    
>>> p = P()
>>> dm = DM()
>>> p._p_oid = oid
>>> p._p_jar = dm
>>> p._p_changed
0
>>> dm.called
0

Modifying the object marks it as changed and registers it with the
data manager.  Subsequent modifications don't have additional
side-effects.

>>> p.inc()
>>> p._p_changed
1
>>> dm.called
1
>>> p.inc()
>>> p._p_changed
1
>>> dm.called
1

It's not possible to deactivate a modified object.

>>> p._p_deactivate()
>>> p._p_changed
1

It is possible to invalidate it.  That's the key difference
between deactivation and invalidation.

>>> p._p_invalidate()
>>> p._p_state
-1

Now that the object is a ghost, any attempt to modify it will
require that it be unghosted first.  The test data manager
has the odd property that it sets the object's 'x' attribute
to 42 when it is unghosted.

>>> p.inc()
>>> p.x
43
>>> dm.called
2

You can manually reset the changed field to False, although
it's not clear why you would want to do that.  The object
changes to the UPTODATE state but retains its modifications.

>>> p._p_changed = False
>>> p._p_state
0
>>> p._p_changed
False
>>> p.x
43

>>> p.inc()
>>> p._p_changed
True
>>> dm.called
3

__getstate__() and __setstate__()
---------------------------------

The next several tests cover the __getstate__() and __setstate__()
implementations.

>>> p = P()
>>> p.__getstate__()
{'x': 0}
>>> p._p_state
0

Calling setstate always leaves the object in the uptodate state?
(I'm not entirely clear on this one.)

>>> p.__setstate__({'x': 5})
>>> p._p_state
0

Assigning to a volatile attribute has no effect on the object state.

>>> p._v_foo = 2
>>> p.__getstate__()
{'x': 5}
>>> p._p_state
0

The _p_serial attribute is not affected by calling setstate.

>>> p._p_serial = "00000012"
>>> p.__setstate__(p.__getstate__())
>>> p._p_serial
'00000012'

Change Ghost test
-----------------

If an object is a ghost and it's _p_changed is set to True, it should
have no effect.

>>> p = P()
>>> p._p_jar = DM()
>>> p._p_oid = 1
>>> p._p_deactivate()
>>> p._p_changed
>>> p._p_state
-1
>>> p._p_changed = True
>>> p._p_changed
>>> p._p_state
-1

Activate, deactivate, and invalidate
------------------------------------

Some of these tests are redundant, but are included to make sure there
are explicit and simple tests of _p_activate(), _p_deactivate(), and
_p_invalidate().

>>> p = P()
>>> p._p_oid = 1
>>> p._p_jar = DM()
>>> p._p_deactivate()
>>> p._p_state
-1
>>> p._p_activate()
>>> p._p_state
0
>>> p.x
42
>>> p.inc()
>>> p.x
43
>>> p._p_state
1
>>> p._p_invalidate()
>>> p._p_state
-1
>>> p.x
42

Test failures
-------------

The following tests cover various errors cases.

When an object is modified, it registers with its data manager.  If
that registration fails, the exception is propagated and the object
stays in the up-to-date state.  It shouldn't change to the modified
state, because it won't be saved when the transaction commits.

>>> p = P()
>>> p._p_oid = 1
>>> p._p_jar = BrokenDM()
>>> p._p_state
0
>>> p._p_jar.called
0
>>> p._p_changed = 1
Traceback (most recent call last):
  ...
NotImplementedError
>>> p._p_jar.called
1
>>> p._p_state
0

Make sure that exceptions that occur inside the data manager's
setstate() method propagate out to the caller.

>>> p = P()
>>> p._p_oid = 1
>>> p._p_jar = BrokenDM()
>>> p._p_deactivate()
>>> p._p_state
-1
>>> p._p_activate()
Traceback (most recent call last):
  ...
NotImplementedError
>>> p._p_state
-1


Special test to cover layout of __dict__
----------------------------------------

We once had a bug in the Persistent class that calculated an incorrect
offset for the __dict__ attribute.  It assigned __dict__ and _p_jar to
the same location in memory.  This is a simple test to make sure they
have different locations.

>>> p = P()
>>> p.inc()
>>> p.inc()
>>> p.__dict__
{'x': 2}
>>> p._p_jar


Inheritance and metaclasses
---------------------------

Simple tests to make sure it's possible to inherit from the Persistent
base class multiple times.  There used to be metaclasses involved in
Persistent that probably made this a more interesting test.

>>> class A(Persistent):
..     pass
>>> class B(Persistent):
..     pass
>>> class C(A, B):
..     pass
>>> class D(object):
..     pass
>>> class E(D, B):
..     pass
>>> a = A()
>>> b = B()
>>> c = C()
>>> d = D()
>>> e = E()

Also make sure that it's possible to define Persistent classes that
have a custom metaclass.

>>> class alternateMeta(type):
..     type
>>> class alternate(object):
..     __metaclass__ = alternateMeta
>>> class mixedMeta(alternateMeta, type):
..     pass
>>> class mixed(alternate, Persistent):
..     pass
>>> class mixed(Persistent, alternate):
..     pass


Basic type structure
--------------------

>>> Persistent.__dictoffset__ 
0
>>> Persistent.__weakrefoffset__
0
>>> Persistent.__basicsize__ > object.__basicsize__
True
>>> P.__dictoffset__ > 0
True
>>> P.__weakrefoffset__ > 0
True
>>> P.__dictoffset__ < P.__weakrefoffset__
True
>>> P.__basicsize__ > Persistent.__basicsize__
True


Slots
-----

These are some simple tests of classes that have an __slots__
attribute.  Some of the classes should have slots, others shouldn't.

>>> class noDict(object):
..     __slots__ = ['foo']
>>> class p_noDict(Persistent):
..     __slots__ = ['foo']
>>> class p_shouldHaveDict(p_noDict):
..     pass

>>> p_noDict.__dictoffset__
0
>>> x = p_noDict()
>>> x.foo = 1
>>> x.foo
1
>>> x.bar = 1
Traceback (most recent call last):
  ...
AttributeError: 'p_noDict' object has no attribute 'bar'
>>> x._v_bar = 1
Traceback (most recent call last):
  ...
AttributeError: 'p_noDict' object has no attribute '_v_bar'
>>> x.__dict__
Traceback (most recent call last):
  ...
AttributeError: 'p_noDict' object has no attribute '__dict__'

The various _p_ attributes are unaffected by slots.
>>> p._p_oid
>>> p._p_jar
>>> p._p_state
0

If the most-derived class does not specify 

>>> p_shouldHaveDict.__dictoffset__ > 0
True
>>> x = p_shouldHaveDict()
>>> x.__dict__
{}


Pickling
--------

There's actually a substantial effort involved in making subclasses of
Persistent work with plain-old pickle.  The ZODB serialization layer
never calls pickle on an object; it pickles the object's class
description and its state as two separate pickles.

>>> import pickle
>>> p = P()
>>> p.inc()
>>> p2 = pickle.loads(pickle.dumps(p))
>>> p2.__class__ is P
True
>>> p2.x == p.x
True

The P2 class has a custom __getstate__ and __setstate__.

>>> p = P2()
>>> p2 = pickle.loads(pickle.dumps(p))
>>> p2.__class__ is P2
True
>>> p2.__dict__
{'v': 42}


=== Zope/lib/python/persistent/tests/test_persistent.py 1.2 => 1.3 ===
--- Zope/lib/python/persistent/tests/test_persistent.py:1.2	Wed Feb 18 21:59:32 2004
+++ Zope/lib/python/persistent/tests/test_persistent.py	Tue Mar  2 17:15:14 2004
@@ -11,10 +11,15 @@
 # FOR A PARTICULAR PURPOSE.
 #
 ##############################################################################
+import doctest
+import new
+import os
+import sys
 import unittest
 
 from persistent import Persistent
 from persistent.interfaces import IPersistent
+import persistent.tests
 
 try:
     import zope.interface
@@ -23,269 +28,7 @@
 else:
     interfaces = True
 
-class Test(unittest.TestCase):
-
-    klass = None # override in subclass
-
-    def testSaved(self):
-        p = self.klass()
-        p._p_oid = '\0\0\0\0\0\0hi'
-        dm = DM()
-        p._p_jar = dm
-        self.assertEqual(p._p_changed, 0)
-        self.assertEqual(dm.called, 0)
-        p.inc()
-        self.assertEqual(p._p_changed, 1)
-        self.assertEqual(dm.called, 1)
-        p.inc()
-        self.assertEqual(p._p_changed, 1)
-        self.assertEqual(dm.called, 1)
-        p._p_deactivate()
-        self.assertEqual(p._p_changed, 1)
-        self.assertEqual(dm.called, 1)
-        p._p_deactivate()
-        self.assertEqual(p._p_changed, 1)
-        self.assertEqual(dm.called, 1)
-        del p._p_changed
-        # XXX deal with current cPersistence implementation
-        if p._p_changed != 3:
-            self.assertEqual(p._p_changed, None)
-        self.assertEqual(dm.called, 1)
-        p.inc()
-        self.assertEqual(p.x, 43)
-        self.assertEqual(p._p_changed, 1)
-        self.assertEqual(dm.called, 2)
-        p._p_changed = 0
-        self.assertEqual(p._p_changed, 0)
-        self.assertEqual(dm.called, 2)
-        self.assertEqual(p.x, 43)
-        p.inc()
-        self.assertEqual(p._p_changed, 1)
-        self.assertEqual(dm.called, 3)
-
-    def testUnsaved(self):
-        p = self.klass()
-
-        self.assertEqual(p.x, 0)
-        self.assertEqual(p._p_changed, 0)
-        self.assertEqual(p._p_jar, None)
-        self.assertEqual(p._p_oid, None)
-        p.inc()
-        p.inc()
-        self.assertEqual(p.x, 2)
-        self.assertEqual(p._p_changed, 0)
-
-        p._p_deactivate()
-        self.assertEqual(p._p_changed, 0)
-        p._p_changed = 1
-        self.assertEqual(p._p_changed, 0)
-        p._p_deactivate()
-        self.assertEqual(p._p_changed, 0)
-        del p._p_changed
-        self.assertEqual(p._p_changed, 0)
-        if self.has_dict:
-            self.failUnless(p.__dict__)
-        self.assertEqual(p.x, 2)
-
-    def testState(self):
-        p = self.klass()
-        self.assertEqual(p.__getstate__(), {'x': 0})
-        self.assertEqual(p._p_changed, 0)
-        p.__setstate__({'x':5})
-        self.assertEqual(p._p_changed, 0)
-        if self.has_dict:
-            p._v_foo = 2
-        self.assertEqual(p.__getstate__(), {'x': 5})
-        self.assertEqual(p._p_changed, 0)
-
-    def testSetStateSerial(self):
-        p = self.klass()
-        p._p_serial = '00000012'
-        p.__setstate__(p.__getstate__())
-        self.assertEqual(p._p_serial, '00000012')
-
-    def testDirectChanged(self):
-        p = self.klass()
-        p._p_oid = 1
-        dm = DM()
-        p._p_jar = dm
-        self.assertEqual(p._p_changed, 0)
-        self.assertEqual(dm.called, 0)
-        p._p_changed = 1
-        self.assertEqual(dm.called, 1)
-
-    def testGhostChanged(self):
-        # An object is a ghost, and it's _p_changed it set to True.
-        # This assignment should have no effect.
-        p = self.klass()
-        p._p_oid = 1
-        dm = DM()
-        p._p_jar = dm
-        p._p_deactivate()
-        self.assertEqual(p._p_changed, None)
-        p._p_changed = True
-        self.assertEqual(p._p_changed, None)
-
-    def testRegistrationFailure(self):
-        p = self.klass()
-        p._p_oid = 1
-        dm = BrokenDM()
-        p._p_jar = dm
-        self.assertEqual(p._p_changed, 0)
-        self.assertEqual(dm.called, 0)
-        try:
-            p._p_changed = 1
-        except NotImplementedError:
-            pass
-        else:
-            raise AssertionError("Exception not propagated")
-        self.assertEqual(dm.called, 1)
-        self.assertEqual(p._p_changed, 0)
-
-    def testLoadFailure(self):
-        p = self.klass()
-        p._p_oid = 1
-        dm = BrokenDM()
-        p._p_jar = dm
-        p._p_deactivate()  # make it a ghost
-
-        try:
-            p._p_activate()
-        except NotImplementedError:
-            pass
-        else:
-            raise AssertionError("Exception not propagated")
-        self.assertEqual(p._p_changed, None)
-
-    def testActivate(self):
-        p = self.klass()
-        dm = DM()
-        p._p_oid = 1
-        p._p_jar = dm
-        p._p_changed = 0
-        p._p_deactivate()
-        # XXX does this really test the activate method?
-        p._p_activate()
-        self.assertEqual(p._p_changed, 0)
-        self.assertEqual(p.x, 42)
-
-    def testDeactivate(self):
-        p = self.klass()
-        dm = DM()
-        p._p_oid = 1
-        p._p_deactivate() # this deactive has no effect
-        self.assertEqual(p._p_changed, 0)
-        p._p_jar = dm
-        p._p_changed = 0
-        p._p_deactivate()
-        self.assertEqual(p._p_changed, None)
-        p._p_activate()
-        self.assertEqual(p._p_changed, 0)
-        self.assertEqual(p.x, 42)
-
-    if interfaces:
-        def testInterface(self):
-            self.assert_(IPersistent.isImplementedByInstancesOf(Persistent),
-                         "%s does not implement IPersistent" % Persistent)
-            p = Persistent()
-            self.assert_(IPersistent.isImplementedBy(p),
-                         "%s does not implement IPersistent" % p)
-
-            self.assert_(IPersistent.isImplementedByInstancesOf(P),
-                         "%s does not implement IPersistent" % P)
-            p = self.klass()
-            self.assert_(IPersistent.isImplementedBy(p),
-                         "%s does not implement IPersistent" % p)
-
-    def testDataManagerAndAttributes(self):
-        # Test to cover an odd bug where the instance __dict__ was
-        # set at the same location as the data manager in the C type.
-        p = P()
-        p.inc()
-        p.inc()
-        self.assert_('x' in p.__dict__)
-        self.assert_(p._p_jar is None)
-
-    def testMultipleInheritance(self):
-        # make sure it is possible to inherit from two different
-        # subclasses of persistent.
-        class A(Persistent):
-            pass
-        class B(Persistent):
-            pass
-        class C(A, B):
-            pass
-        class D(object):
-            pass
-        class E(D, B):
-            pass
-
-    def testMultipleMeta(self):
-        # make sure it's possible to define persistent classes
-        # with a base whose metaclass is different
-        class alternateMeta(type):
-            pass
-        class alternate(object):
-            __metaclass__ = alternateMeta
-        class mixedMeta(alternateMeta, type):
-            pass
-        class mixed(alternate,Persistent):
-            __metaclass__ = mixedMeta
-
-    def testSlots(self):
-        # Verify that Persistent classes behave the same way
-        # as pure Python objects where '__slots__' and '__dict__'
-        # are concerned.
-
-        class noDict(object):
-            __slots__ = ['foo']
-
-        class shouldHaveDict(noDict):
-            pass
-
-        class p_noDict(Persistent):
-            __slots__ = ['foo']
-
-        class p_shouldHaveDict(p_noDict):
-            pass
-
-        self.assertEqual(noDict.__dictoffset__, 0)
-        self.assertEqual(p_noDict.__dictoffset__, 0)
-
-        self.assert_(shouldHaveDict.__dictoffset__ <> 0)
-        self.assert_(p_shouldHaveDict.__dictoffset__ <> 0)
-
-    def testBasicTypeStructure(self):
-        # test that a persistent class has a sane C type structure
-        # use P (defined below) as simplest example
-        self.assertEqual(Persistent.__dictoffset__, 0)
-        self.assertEqual(Persistent.__weakrefoffset__, 0)
-        self.assert_(Persistent.__basicsize__ > object.__basicsize__)
-        self.assert_(P.__dictoffset__)
-        self.assert_(P.__weakrefoffset__)
-        self.assert_(P.__dictoffset__ < P.__weakrefoffset__)
-        self.assert_(P.__basicsize__ > Persistent.__basicsize__)
-
-    def testDeactivateErrors(self):
-        p = self.klass()
-        p._p_oid = '\0\0\0\0\0\0hi'
-        dm = DM()
-        p._p_jar = dm
-
-        def typeerr(*args, **kwargs):
-            self.assertRaises(TypeError, p, *args, **kwargs)
-
-        typeerr(1)
-        typeerr(1, 2)
-        typeerr(spam=1)
-        typeerr(spam=1, force=1)
-
-        p._p_changed = True
-        class Err(object):
-            def __nonzero__(self):
-                raise RuntimeError
-
-        typeerr(force=Err())
+oid = "\0\0\0\0\0\0hi"
 
 class P(Persistent):
     def __init__(self):
@@ -332,42 +75,42 @@
     def setstate(self,ob):
         raise NotImplementedError
 
-class PersistentTest(Test):
-    klass = P
-    has_dict = 1
-
-    def testPicklable(self):
-        import pickle
-
-        p = self.klass()
-        p.inc()
-        p2 = pickle.loads(pickle.dumps(p))
-        self.assertEqual(p2.__class__, self.klass)
-
-        # verify that the inc is reflected:
-        self.assertEqual(p2.x, p.x)
-        
-        # This assertion would be invalid.  Interfaces
-        # are compared by identity and copying doesn't
-        # preserve identity. We would get false negatives due
-        # to the differing identities of the original and copied
-        # PersistentInterface:
-        # self.assertEqual(p2.__dict__, p.__dict__)
-
-    def testPicklableWCustomState(self):
-        import pickle
-
-        p = P2()
-        p2 = pickle.loads(pickle.dumps(p))
-        self.assertEqual(p2.__class__, P2);
-        self.assertEqual(p2.__dict__, {'v': 42})
-
-class BasePersistentTest(Test):
-    klass = B
-    has_dict = 0
+class Test(unittest.TestCase):
+
+    # XXX This is the only remaining unittest.  Figure out how to move
+    # this into doctest?
+
+    if interfaces:
+        def testInterface(self):
+            self.assert_(IPersistent.isImplementedByInstancesOf(Persistent),
+                         "%s does not implement IPersistent" % Persistent)
+            p = Persistent()
+            self.assert_(IPersistent.isImplementedBy(p),
+                         "%s does not implement IPersistent" % p)
+
+            self.assert_(IPersistent.isImplementedByInstancesOf(P),
+                         "%s does not implement IPersistent" % P)
+            p = self.klass()
+            self.assert_(IPersistent.isImplementedBy(p),
+                         "%s does not implement IPersistent" % p)
+
+def DocFileSuite(path):
+    # It's not entirely obvious how to connection this single string
+    # with unittest.  For now, re-use the _utest() function that comes
+    # standard with doctest in Python 2.3.  One problem is that the
+    # error indicator doesn't point to the line of the doctest file
+    # that failed.
+    source = open(path).read()
+    t = doctest.Tester(globs=sys._getframe(1).f_globals)
+    def runit():
+        doctest._utest(t, path, source, path, 0)
+    f = unittest.FunctionTestCase(runit, description="doctest from %s" % path)
+    suite = unittest.TestSuite()
+    suite.addTest(f)
+    return suite
 
 def test_suite():
-    s = unittest.TestSuite()
-    for klass in PersistentTest, BasePersistentTest:
-        s.addTest(unittest.makeSuite(klass))
+    p = os.path.join(persistent.tests.__path__[0], "persistent.txt")
+    s = unittest.makeSuite(Test)
+    s.addTest(DocFileSuite(p))
     return s




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