The testrunner reports all tests passed after these changes.
Remove unnecessary path munging and attempts to import ZODB.
Update uses of whrandom to use random.

VerboseTextTestRunner() => TestTestRunner(verbosity=2)

glob() and os.remove().

properly.

writes after an abort.  This specifically flexes a bug discovered by
Shane in Full storage.

bug.

instead of any other error that may be raised.

After consultation with Jim, we agreed that Full's behavior vis object
serial numbers after a version commit/abort are correct.  The new
revision should get the serial number of the transaction that did the
commit/abort.

FileStorage is actually broken here; the new revision gets the same
serial number as the last in-version revision.  However, the way the
tests are written, it works for either storage, so I'm just updating
some comments to explain the situation.

Note: Jim also explained that history()'s "version" argument should be
ignored.  Doesn't make much difference to these tests though.

storage API.

including self) to be called `size' not `length'.  This should be
considered part of the contract of this method, so the keyword
argument name has been changed.

subclass Transaction.

made keys() method return a *copy* of the cached keys list, preventing mutations of the cached keys list that could cause later problems.  (Collector 2283).

(Collector #2277)

If an exception is raised, make sure the current transaction is
aborted.  And catch more of the oddball exceptions that can get raised
when a server disconnects -- like thread.error.

Note that requirement of Zope 2.2 or higher.  Explain how to put
cPickle in the right place in your Zope tree.

Add checkReconnection() to renamed ConnectionTests (was
PersistentCacheTests).

Close the client storage explicitly in the tear down to avoid spurious
warnings from threads attempting to connect after the test is over.

closeIntensionally() is called when the storage's close() method is
called.  close() is called when the other end reset the connection.
The __closed should only be set with the asyncRPC object should never
re-open the connection.

Reported by Dyon Balding.

partially committed.  If an object is stored more than once in a
version during a single transaction (which is borderline behavior anyway)
and that object has been modified for the first time in the version,
the old logic would stop prematurely.

Many methods had default arguments that were used to bind a global or
builtin name, like type, None, or type(''), as a local name.  In many
cases, the names bound were not referenced in the method body
(presumably they used to be referenced).

commit_sub(): In this one case, delete the default arg anyway, because
    it's only used once.

The same effect can be achieved by:
db.begin_invalidation()
for oid in oids_to_invalidate:
    db.invalidate(oid)
db.finish_invalidation()