How to Develop Dependencies With Buildout

Given you have a decent sized project, with some dependencies…

How can you develop and test a dependency against your main project, when it is not yet published on PyPi?

Well, until recently, I relied on a strong test suite and mostly developed “blindly”.

When I wanted to see the result, I used Vim to directly edit the dependency in my virtual env.

There must be a better way

And actually, there is and has been for more than a decade. Say hello to mr.developer.

While I heard of mr.developer on some of the Zope sprints, I never felt the urge to use it.

But the time has come.

I maintain a project called Products.ZopeTree.

The plan is to delete a file which is not under test.

The easiest way - delete it and have a look whether the app is still running, right?

This is where mr.developer shines.

As I develop this one app via zc.buildout, I just have to add a couple of lines:

[buildout]
extensions = mr.developer
auto-checkout = *

[sources]
Products.ZopeTree = git git@github.com:jugmac00/Products.ZopeTree.git

Then I run bin/buildout and instead of pulling the app from PyPI, it gets checked out from GitHub.

In hindsight… I could have tried this much, much earlier :-)