I want a mercurial hook that will run JSLint/PyChecker/etc on all files that are modified. However, I do not have control over all hg clients, and want this to run on push to the master repository (which I have control), so a pretxnchangegroup hook on the master seems best.
How can I get a list of all changesets that are in the changegroup that is going to be committed?
I have seem other solutions that use a precommit hook, but these will not work for me because the clients may already have a commit that fails JSLint. In this case, they should be able to fix the errors in a new commit, and be able to push (both the bad and new commits) to the server successfully. The server just needs to check the most recent changeset on each branch, of every file that was modified in the changegroup.
You're right that you want a pretxnchangegroup hook, but you don't want to check all the new revisions -- because people will fix the errors you reject in subsequent changesets but if you're checking all changesets their work will never be accepted!
Instead either just check all files in all the heads, or use the hg status --rev x:y syntax to get a list of the changed files between the revision you already have and the tip revision you're receiving, and check only those files only in the tip revision.
If you really want the list of all revisions you'd use a revset ( hg help revsets ) new in version 1.6, but you really only want to check the results, not all the revisions that get you there.
Get list of changesets in a changegroup (mercurial python hook)