root/test_dirtree_posix.txt

Testing the ``dirtree`` module
==============================

The ``dirtree`` module contains functions and classes to scan
directory trees recursively.

Testing the ``dir_level`` helper function
-----------------------------------------

The function ``dir_level`` returns the "depth" of a directory. For
this it uses the heuristics of counting the path separators in a
path. The following tests are intended to run under Posix systems::

    >>> import dirtree

    >>> dirtree.dir_level("/the/root/directory")
    3
    >>> dirtree.dir_level("/dir")
    1

As a special case, the root directory has a directory level of 0,
since it's "above" a directory located in the root directory::

    >>> dirtree.dir_level("/")
    0

Testing the ``DirectoryTree`` class
-----------------------------------

The class is instantiated with the root of the directory tree to
scan. To test the class, use it on a known directory, the
Websourcebrowser project directory. Note that the test routine sets
the project directory as the current directory, so the following code
should work. (To make the test independent of the actual directory,
we have to jump through some hoops.)

::

    >>> import os
    >>> # assume the current directory holds the project
    >>> project_dir = os.getcwd()
    >>> dt = dirtree.DirectoryTree(".")
    >>> dt.read()
    >>> for item in dt.items:
    ...     print item.replace(project_dir, "pd")  #doctest: +ELLIPSIS
    pd/.hg
    ...
    pd/graphics/logo.png
    ...
    pd/browser.py
    ...
    pd/converter.py
    ...

If the root directory isn't accessible, raise a ``ReadError``
exception::

    >>> dt = dirtree.DirectoryTree("/root/testdir")
    >>> dt.read()   #doctest: +ELLIPSIS
    Traceback (most recent call last):
        ...
    ReadError: root '/root/testdir' can't be scanned

If we limit the directory depth (``depth``) to 1, the "lower"
directory items shouldn't be present::

    >>> dt = dirtree.DirectoryTree(".")
    >>> dt.read(depth=1)
    >>> items = [item.replace(project_dir, "pd") for item in dt.items]
    >>> "pd/browser.py" in items
    True
    >>> "pd/graphics" in items
    True
    >>> "pd/graphics/logo.png" in items
    False

Upon reading the directory, the ignore patterns from the ``config``
module are applied automatically::

    >>> import config
    >>> config.ignore_patterns = ["*.pyc"]
    >>> dt = dirtree.DirectoryTree(".")
    >>> dt.read()
    >>> items = [item.replace(project_dir, "pd") for item in dt.items]
    >>> "pd/browser.pyc" in items
    False