contrib: add a set of scripts to run pytype in Docker
Having a simple way to run pytype for developers can massively shorten
development cycle. Using the same Docker image and scripts that we use on our
CI guarantees that the result achieved locally will be very similar to (if not
the same as) the output of our CI runners.
Things to note: the Dockerfile needs to do a little dance around user
permissions inside /home/ci-runner/ because:
- on one hand, creating new files on the host (e.g. .pyi files inside .pytype/)
should use host user's uid and gid
- on the other hand, when we run the image as uid:gid of host user, it needs to
be able to read/execute files inside the image that are owned by ci-runner
Since local user's uid might be different from ci-runner's uid, we execute this
very broad chmod command inside /home/ci-runner/, but then run the image as the
host user's uid:gid.
There might be a better way to do this.
Our full contribution guidelines are in our wiki, please see:
https://www.mercurial-scm.org/wiki/ContributingChanges
If you just want a checklist to follow, you can go straight to
https://www.mercurial-scm.org/wiki/ContributingChanges#Submission_checklist
If you can't run the entire testsuite for some reason (it can be
difficult on Windows), please at least run `contrib/check-code.py` on
any files you've modified and run `python contrib/check-commit` on any
commits you've made (for example, `python contrib/check-commit
273ce12ad8f1` will report some style violations on a very old commit).