pytest-watch -- Continuous pytest runner

pytest-watch a zero-config CLI tool that runs pytest, and reruns it when a file in your project changes.

Motivation

Whether or not you use the test-driven development method, running tests continuously is far more productive than waiting until you're finished programming to test your code. Additionally, manually running py.test each time you want to see if any tests were broken has more wait-time and cognitive overhead than merely checking the terminal here and there. This could be a crucial difference when debugging a complex problem or on a tight deadline.

Installation

$ pip install pytest-watch

Usage

$ cd myproject
$ ptw
 * Watching /path/to/myproject

It can also be run using the longhand, py.test.watch.

Now develop normally and check the terminal every now and then to see if any tests are broken.

Alternatives

xdist offers the --looponfail (-f) option (and distributed testing options). This instead re-runs only those tests which have failed until you make them pass. This can be a speed advantage when trying to get all tests passing, but leaves out the discovery of new failures until then. It also drops the colors outputted by py.test, whereas pytest-watch doesn't.
Nosey is the original codebase this was forked from. Nosey runs nose instead of pytest.

Contributing