FrequentlyAskedQuestions

Why is <your favourite REQUEST variable here> missing from the REQUEST?

ZTC only has a very minimal REQUEST. If you need anything fancy in the REQUEST (like SESSION, PARENTS, URL1, ...) you will have to put it there yourself, typically in afterSetUp. See e.g. testShoppingCart.py.

How do I enable the Zope event log?

To enable the event log you have to set the required environment variables before importing ZopeTestCase. Your test*.py file should begin with something like:

    os.environ['EVENT_LOG_FILE'] = os.path.join(os.getcwd(), 'zLOG.log')
    os.environ['EVENT_LOG_SEVERITY'] = '-300'

    from Testing import ZopeTestCase

How do I test an existing ZODB?

Create a custom_zodb.py file in your tests directory that looks like the following:

     import os
     from ZODB.DemoStorage import DemoStorage
     from ZODB.FileStorage import FileStorage
     db = os.path.join('..', '..', '..', 'var', 'Data.fs')
     db = os.path.abspath(db)
     Storage = DemoStorage(base=FileStorage(db, read_only=1))

This way your test DemoStorage will be based on the existing FileStorage. You may safely play around in the DemoStorage without having to fear corruption of the base db.

How do I attach to a running ZEO server?

1. Setup a ZEO server and start it.
2. Setup a Zope instance as ZEO client. The instance directory must contain a custom_zodb.py file.
3. Set the ZEO_INSTANCE_HOME environment variable to point to the instance directory.
4. Run the tests by typing python testBlahBlah.py or python runalltests.py.

ZopeTestCase will then use the instance's custom_zodb.py to connect to the ZEO server instead of setting up the test DemoStorage.

Alternatively, you can add the custom_zodb.py file to the tests directory along the lines of the previous example, and skip steps 2 and 3.

Background information is available here: ZopeEnvironment

Why does cut/copy/paste/clone/rename give CopyErrors?

Should you have problems with these operations make sure a _p_jar is set up by performing a subtransaction commit:

     get_transaction().commit(1)

I found this documented in the sources of OFS/CopySupport.py, see method _getCopy().

Simon Michael reports this hint did not work for him, and he had to resort to a hack and set ZwikiPage.cb_isMoveable = lambda x:1. I plan to look into this.

Why does import/export give AttributeErrors?

You may see "None object has no attribute ..." errors when trying to import or export a Zope object. Should you see such errors make sure a _p_jar is set up by performing a subtransaction commit like above.

Is it allowed to explicitly commit a transaction in a test?

While it is allowed to commit a subtransaction as hinted above, committing a full (complete?) transaction is generally not recommended. Transactions are supposed to be handled transparently by ZopeTestCase, and you have to be careful to cleanup your own mess once you call get_transaction().commit() inside of afterSetUp or a test method. The testWebserver.py example shows how one might go about committing manually, but you will rarely want to do so - honest.