==============
Zope doc tests
==============

Doctests are a way to write tests while documenting the thing that is
tested at the same time.  As an example, this file both documents
Zope doc tests *and* tests them.

Doctests look like regular interactive interpreter sessions.  That
makes them very easy to create.  Doctests can either occur in an
object's or method's docstring or in a separate file.  Use either
``DocTestSuite`` or ``DocFileSuite`` in these cases.


Creating Zope doc tests
-----------------------

Creating doc tests for Zope is easy.  While we cannot simply use an
interpeter shell to write our tests, we can reuse the ZopeTestCase
infrastructure to set up the necessary environment.

1. Create a text file, just like this one, containing prose
   documentation interspersed with doctest ``Examples``.

2. In a test module import ``ZopeDocFileSuite`` and instantiate it,
   passing the name of the text file containing the tests.
   For example:

   from unittest import TestSuite
   from Testing.ZopeTestCase import ZopeDocFileSuite

   def test_suite():
       return TestSuite((
           ZopeDocFileSuite('ZopeDocTest.txt'),
       ))


Examples
--------

Here we are going to demonstrate that everything we know about
ZopeTestCase is still true for doc tests. In particular, the default
fixture is set up for doc tests just like for unit tests.

  >>> from Testing.ZopeTestCase import folder_name, user_name
  >>> from AccessControl import getSecurityManager

There should be a folder:

  >>> folder_name in self.app.objectIds()
  True

Containing a user folder:

  >>> 'acl_users' in self.folder.objectIds()
  True

Containing the default user:

  >>> user = self.folder.acl_users.getUserById(user_name)
  >>> user is None
  False

The default user should be logged in:

  >>> getSecurityManager().getUser().getId() == user_name
  True

The custom setUp method should have been run as well. See
testZopeDocTest.py for its definition.

  >>> 'object' in self.folder.objectIds()
  True

Now let's manipulate our test objects a bit:

  >>> ob = self.folder.object
  >>> print ob.title_or_id()
  object

  >>> ob.manage_changeProperties(title='Foo')
  >>> print ob.title_or_id()
  Foo

  >>> self.folder.manage_delObjects('object')
  >>> 'object' in self.folder.objectIds()
  False

