tito/HACKING

Hacking
=======

Python versions
---------------

Tito supports Python versions 2.4 (RHEL 5) and up.
See http://docs.python.org/dev/howto/pyporting.html
and http://python3porting.com/differences.html
for tips on writing portable Python code.

In particular, you must capture exceptions in a way that's
compatible with both python 2.4 and 3.x. For example:

    try:
        raise Exception()
    except Exception:
        import sys
        exc = sys.exc_info()[1]
        # Current exception is 'exc'.
        pass


Tests
-----

To run all tests, install these packages:

* python-nose,  python-pep8,  and rpm-python
* python3-nose, python3-pep8, and rpm-python3
* createrepo

Then from the root of the project:

    python  ./runtests.py -vv
    python3 ./runtests.py -vv test/unit

(Run only the unit tests on python3 since GitPython does not
support python3 yet.)


When developing code for tito there are a couple ways you can test:

"bin/tito-dev" is a script that will run code from the local checkout
rather than what is installed on the system.

And of course, you can always use the installed tito to replace
itself with a test build of the latest *committed* code in your
git HEAD.

    tito build --rpm --test -i

If you screw anything up inside tito itself, you can just:

    rpm -e tito
    yum install tito


Code style
----------

Python3 does not allow mixing tabs and spaces for indentation.
http://docs.python.org/3.3/reference/lexical_analysis.html

You can force your editor to do the right thing by installing
a plugin for your editor from http://editorconfig.org/#download

For example, add the EditorConfig plugin for vim like this:

    cd /tmp/
    wget https://github.com/editorconfig/editorconfig-vim/archive/master.zip
    unzip master.zip
    mkdir ~/.vim
    cp -r editorconfig-vim-master/* ~/.vim/