Beer and Tell – October 2014

Once a month, web developers from across the Mozilla Project get together to debate which episode is the best episode of Star Trek: The Next Generation. Between screaming matches, we generally find time to talk about our side projects and drink, an occurrence we like to call “Beer and Tell”.

There’s a wiki page available with a list of the presenters, as well as links to their presentation materials. There’s also a recording available courtesy of Air Mozilla.

Peter Bengtsson: django-html-validator

Our first presenter, peterbe, has created a small library called django-html-validator that helps perform HTML validation via either a middleware that runs on every request, or a test request client that you can replace the default TestCase client with. It validates by sending the HTML to validator.nu, but can also be set up to use vnu.jar locally to avoid spamming the service with validation requests.

Peter Bengtsson: Pure JS Autocomplete

Previously, peterbe showed an autocomplete engine based on JavaScript that called out to a search index stored in Redis. This time he shared some new features:

  • No dependencies on jQuery or Bootstrap.
  • Tab-triggered autocomplete.
  • Preview of the autocompleted word.

There’s no library for the engine yet, but a demo is up on peterbe’s webpage and the code is located in the Github repository for his personal site.

Matthew Claypotch: flight-status

Uncle potch had a very simple command-line program to show us called flight-status. It pulls the current status of a flight by scraping the FlightAware webpage for a flight using request and cheerio.

Matthew Claypotch: stylecop

stylecop was born from potch’s need to enforce some interesting style guidelines against the CSS used in Brick. stylecop parses CSS and allows you to specify interesting rules via JavaScript code that normal CSS linters can’t find, such as ensuring all classes start with a specific namespace, or that any tag selectors are used as direct descendants.

Pomax: Bezier.js

In a continuing trend of useful and math-y libraries, Pomax showed off Bezier.js, a library for computing Bézier curves, their inflection points, intersections, etc. The library is based of his work for “A Primer on Bézier Curves” and a demo and documentation for the library is available.

Robert Helmer: freebsdxr

DXR is a code search and navigation tool that Mozilla develops to help navigate the Firefox source code. rhelmer shared his work-in-progress of adapting DXR to index the FreeBSD source code. It brings the goodness of DXR, such as full-text searching and structural queries (e.g. “Find all the callers of this function”) to FreeBSD. rhlemer’s work is available as a branch on his Github repo.

Chris Lonnen: leeroybot

Finally, lonnen stopped by to share some info about leeroybot, a customized version of Hubot used by the Release Engineering team. Along with alterations to the plugins that normally come with Hubot, leeroybot is updated and deployed by TravisCI automatically whenever a change is pushed to the master branch.


If we’ve learned anything this week, it’s that you should never allow someone to bring a Bat’leth to a Star Trek debate.

If you’re interested in attending the next Beer and Tell, sign up for the dev-webdev@lists.mozilla.org mailing list. An email is sent out a week beforehand with connection details. You could even add yourself to the wiki and show off your side-project!

See you next month!