Writing code for Launchpad

William Grant was the first person outside Canonical to submit a patch to the newly open sourced Launchpad. I asked him a few questions to see how he got on.

Matthew: What did your patch change?

William: Launchpad users may elect to receive the bug’s description and status in the footer of each bug change notification email. This helps keep track of context when dealing with lots of different bugs.

Previously, bug emails that got to you through a team wouldn’t respect the setting — email coming through some teams would have the description, but for other teams it would be omitted. My fix ensures that the user’s selection is respected even for team emails.

Matthew: Why did you take the time to contribute to the Launchpad codebase?

William: I use Launchpad Bugs a lot, and get a lot of bug mail. This is an issue that has been irritating me for some time, and the fix seemed simple enough, so I decided it might be a good first task.

Matthew: How was it finding your way around the source tree?

William: It was easier than I expected. Most of the Bugs code now conveniently lives in lp.bugs, so I wasn’t overwhelmed with having to deal with the whole tree at first. The extensive test suite (particularly some good doctests) pointed me in the right direction, and developers and grep showed me the rest.

Matthew: How easy/hard was it to make your changes and stick to the Launchpad coding guidelines?

William: I didn’t get it quite right at first, but once pointed at the guidelines, it was simple to make my code compliant. It ended up looking a lot cleaner.

Matthew: What about the review process?

William: Remarkably easy. I found a reviewer (Graham Binns) on IRC, and submitted a merge proposal for my branch. A couple of hours and a few test changes later, my branch was approved. Graham landed it as soon as PQM reopened.

Matthew: What advice do you have for other people considering writing a patch for Launchpad?

William: Do it — it’s great to be able to fix those issues that have been bugging you for ages, and it’s not as hard as it looks. The test suite is a great guide through much of the codebase, and there are always developers on IRC to point you in the right direction if you get lost. The reviews are quick, developers are friendly, code style guidelines are clear, releases are frequent… all up it’s a very pleasant experience.

Matthew: Thanks William!

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