Launchpad Code Reviews Without A Browser
I do a lot of code review in Launchpad, use a lot of the code features, and have worked out some pretty good methods of making this simple and easy to work with. I thought, in lieu of my last post, and the ones I'm planning for the near future, it'd be good to detail some of the things that I do to make my workflow.
Launchpad's web UI is slow. I'll admit it. We're working on doing some really great things to speed it up, but frankly, all web applications are. You've got to load pages, parse javascript, etc. In fact, most things you shouldn't even have to wait around for. They are things that should require minimal attention for much of the time, and often things that are "fire and forget."
So let's build off the config settings I've already blogged about. If you haven't read that article yet, I highly suggest you go back and read it, or you're gonna get really confused really quick.
Creating a merge proposal with email
Looking back on the general Launchpad branch configs we used, we need to add one more line so that Bazaar knows the email address that Bazaar's "bundles" should go to. So, let's edit our ~/.bazaar/locations.conf to show the following:
[/home/rockstar/Projects/repos]
push_location = lp:~rockstar/
push_location:policy = appendpath
public_branch = lp:~rockstar/
public_branch:policy = appendpath
submit_to = merge@code.launchpad.net
The line added is the submit_to line. This means that Bazaar is going to send its bundles to merge@code.launchpad.net. This is the email address that parses the bundle, and derives the the source branch (the branch to be merged) and the target branch (the branch to merge into).
Now we need to specify the submit branch. This requires some specific configs for each project, so we'll need to add a new section. For this example, we're going to use Entertainer since Bazaar's development doesn't use Launchpad for it's review process. I'm going to add another section specific to Entertainer.
# Entertainer
[/home/rockstar/Projects/repos/entertainer]
submit_branch = lp:entertainer
This sets all branches in ~/Projects/entertainer to submit to the branch lp:entertainer which happens to be the current development focus of Entertainer. Note: The target branch MUST be a Launchpad branch. The source branch doesn't really need to be, and Launchpad is smart enought to create a Remote branch (a branch that Launchpad only keeps a reference of).
Finally, we need to tell Bazaar what your preferred email client is. So crack open ~/.bazaar/bazaar.conf and let's add one more line to the [DEFAULT] section.
mail_client = evolution
Wait. You don't want to use evolution to send your email? Well, you can choose between thunderbird, evolution, kmail, thunderbird, mutt, emacsclient (although I don't know how that emacsclient works), or editor. I use editor, but that requires some more config set up (and it's beyond the scope of this post). Also, if you want to use Gmail, see BzrSendWithGmail or use James Henstridge's bzr-imapclient plugin to use GMail to send the merge-directive (see https://lists.ubuntu.com/archives/bazaar/2009q1/051602.html. As of Bazaar 1.11, bzr also now supports claws as a mail_client as well.
Now, hacka hack on your branch, and when it's all ready, make sure it's pushed to Launchpad, and then do bzr send --no-bundle. This will create a bundle and open up your mail client for you to detail what your branch does. Fill that out, and send the email. It'll be processed, and the merge proposal will be created, using the Default Reviewer for the target branch as the reviewer.
Reviewing a branch through email
This is where things get more interesting. Those subscribed to the branch (as branch code reviewers should be) will get an email with the creation of the merge proposal, and an email with the patch (these two emails will be consolidated shortly).
So a reviewer cracks open the email and looks through the patch. They merge the branch into their local mirror of trunk and run the tests (because you have tests for code, right?). The reviewer makes their inline comments to the patch in the email reply. The To: in their reply should be something like mp+1234@code.launchpad.net.
If you (as reviewer) were to send this email now, it'll be parsed as a comment to the merge proposal. What if you want to give an official review vote? What if you want to set the merge proposal status to Approved? This is the clever part. For example, I review a branch and I think it needs to be set to Needs Fixing. Within the email, I would type:
vote needs_fixing
Note the leading space there. It's important. Now, GPG sign your email, and send it off. You've just given your vote. After someone decides to fix the issues that arose from your review, you can reply to the response email with:
vote approve
status approved
Send this with a GPG signed email, and you've updated the merge proposal to Approved as well as "voted" approve. Now, if you can merge the branch, merge it, otherwise, nudge someone who can.
Hooray! You've successfully navigated the hairy process of code review without having to hassle with the web UI at all. Now THAT'S a service worth working with. There are similar commands to work with bugs as well, and by learning to use these commands, you can create a workflow with Launchpad that works best for you.
Update: Thanks to some great comments, I've noted some of extras.