# Additional doctest Tests

Most doctest module tests are located within the module. This file only tests a few additional features not covered by the module tests, so that the changes to the doctest module – which is forked from the Python standard library – are minimized.

## Working with Carriage Returns

Due to the way releases are made on different platforms, we sometimes test files on a *nix system with Windows file endings. Unfortunately, that leaves some of the test files broken:

    >>> import tempfile
    >>> fn = tempfile.mktemp()
    >>> foo = open(fn, 'w').write('Test:\r\n\r\n  >>> x = 1 + 1\r\n\r\nDone.\r\n')

Let’s now run it as a doctest:

    >>> from zope.testing import doctest
    >>> a, b = doctest.testfile(fn, False) # doctest 2.6 and later uses a named tuple here.
    >>> a, b
    (0, 1)

It worked. Let’s also try the test file suite:

    >>> import unittest
    >>> result = unittest.TestResult()
    >>> doctest.DocFileSuite(fn, module_relative=False).run(result)
    <...TestResult run=1 errors=0 failures=0>