Custom docs checkers in yelp-check

I have a personal goal of getting top-notch docs CI in place for GNOME 40, and part of that is having checks for merge requests. We have a number of great checks already in yelp-check, like checking for broken links and media references, but for large documents sets, you want to be able to enforce your own rules for style and consistency. The most common tool for this is Schematron, and in fact we do have a Schematron file in gnome-help. But it has a lot of boilerplate, most people don’t know how to write it, and the command to run it is unpleasant.

I’ve been rewriting yelp-check in Python. This has made it easy to implement things that were just not fun with /bin/sh. (It’s also way faster, which is great.) Today I added the ability to define custom checkers in a config file. These checkers use the same idea as Schematron: assert something with XPath and bomb if it’s false. But they’re way easier to write. From my commit message, here’s one of the checks from the gnome-help Schematron file, reworked as a yelp-check checker:

[namespaces]
mal = http://projectmallard.org/1.0/

[check:gnome-desc]
select = /mal:page/mal:info
assert = normalize-space(mal:desc) != ''
message = Must have non-empty desc

With the new yelp-check (as yet not released), you’ll be able to just run this command:

yelp-check gnome-desc

All of the custom checkers show up the the yelp-check usage blurb, alongside the builtin checks, so you can easily see what’s available.

The next steps are to let you define sets of commands in the config file, so you can define what’s important for you on merge requests, and then to provide some boilerplate GitLab CI YAML so all docs contributions get checked automatically.

Creative Commons Attribution 3.0 United States
This work by Shaun McCance is licensed under a Creative Commons Attribution 3.0 United States.