I discovered Jason Pellerin's nose test discovery and execution tool when I started using TurboGears. My first forays into test driven development and automated Python testing weren't all that successful though. Then this talk by Jonathan Hartley, and this one by Titus Brown at PyCon 2008, and a lobby chat with Jonathan just before I left Chicago got me thinking differently, and more seriously about automated testing. A few days later, the penny dropped, and I'm a convert!
Then I came across a little script called nosy that Jeff Winkler described in a (now vanished) blog post in April of 2006. nosy runs nose whenever a source file has changed. I'd thought about doing something like that but was thinking I'd have to use some kind of continuous integration system like buildbot, and that seemed like a whole lot of trouble for some little personal projects. Jeff's trick for calculating a checksum for the source files makes it all very, very easy. His original nosy.py script was less than 20 lines long!
I liked nosy on sight but after playing with it for a short time wanted to add features and flexibility. I like to keep my test code in a tests/ directory, separate from my project code. I wanted nose to run whenever I changed either the project code, or the test code. I wanted to be able to change the way nose ran, turning options like -s and -v on or off, and specifying particular parts of the test suite to run via command line arguments.
So, I decided that nosy needed the option of having a configuration file. Of course that meant that it needed a command line processor. ConfigParser and optparse from the Python standard library to the rescue, and we have my version of nosy:
$ nosy -h
Usage: nosy [options]
Automatically run nose whenever source files change.
Options:
-h, --help show this help message and exit
-c CONFIG_FILE, --config=CONFIG_FILE
configuration file path and name; defaults to
setup.cfg
You should be able to install nosy with:
$ pip install -U nosy
Throw a section something like this into your setup.cfg file:
# Sample config file section for nosy # Including this file in the paths to check allows you to change # nose's behaviour on the fly. [nosy] # Paths to check for changed files; changes cause nose to be run base_path = ./ glob_patterns = *.py exclude_patterns = *_flymake.* extra_paths = setup.cfg # Command line options to pass to nose options = -x # Command line arguments to pass to nose; e.g. part of test suite to run tests = tests/unit_tests.py
launch nosy:
$ nosy
and away you go. nose will run whenever any of the *.py files in your project, or setup.cfg change.
If you prefer, you can use a separate config file just for nosy, say tests/nosy.cfg, and launch nosy with:
$ nosy -c tests/nosy.cfg
As of version 1.1 nosy has new configuration options to make it easier to use in projects with deep directory structures. The checksum calculator now uses os.walk() starting from base_path, including files given by a list of glob_patterns, excluding those given by a list of exclude_patterns. Files given by the extra_paths list are also glob-ed in to handle anything that the first 3 options don't easily catch. Thanks to Jussi Rasinmäki for the suggestion.
Putting the config file itself in the list of files to watch (typically via the extra_paths option) allows you to change how nose runs without having to stop and restart nosy.
options are the command line options to pass to nose. Use -v to turn on verbose output, or -a foo to run only the tests with attribute foo.
tests are the command line arguments to pass to nose, used to select specific tests to run.