JavaScript Chat Summary: March 10, 2020

Below is a summary of the discussion from this week’s JavaScript chat (agendaSlack transcript).

Have a topic for discussion for the next meeting? Leave a suggested edit on next week’s agenda.

News roundup proposal

(Slack conversation)

@nerrad as been kind enough to offer to share an aggregate of news relevant in the Gutenberg and general JavaScript ecosystem, to include in the summary notes for each week’s meeting.


  • There was an agreement that it’s a great idea.
  • The plan is to add this as an extra section in our JavaScript chat summary starting from this week.

Action items:

  • New agendas should be structured to include separate sections “Agenda Topics” and “News Roundup”
  • Note-takers should aim to include these items in the published summary notes.
  • Update “Note Takers” document guidelines.

ESLint “prefer-const” relaxation proposal

(Slack conversation)

@aduth added a pull request about a potential revision to our default ESLint configurations (i.e. coding standards) at He just wanted to bring it to attention, since any of these sorts of coding standards changes are good to highlight. There’s been some positive feedback already on the pull request that was echoed in the chat.

Visual regression testing tools

(Slack conversation)

@isabel_brison created a ticket to introduce visual regression testing in the WordPress core, so we can clean up some of the old CSS with confidence. She was wondering if this type of testing has been discussed or explored at all for core or Gutenberg. Also, would there be value in adding it for Gutenberg, too?


There’s no visual regression testing in Gutenberg as of today, but there are parts of the tooling that could make it possible, like taking screenshots with the headless browser via Puppeteer. At least with the ticket as presented, it seems primarily focused on existing screens which may not be expected to change, and thus primarily with the aim of preventing regressions while doing CSS refactoring.

The tests themselves are minimal, but the reference images are not insignificant though and need to be updated periodically. The biggest concern is the size of the assets that would have to be maintained and how to ensure they don’t pollute repositories with source code.

There is an existing prototype in the Gutenberg repository ( that uses 3rd party service that can be used as a reference when exploring the final implementation.

Introduce a common API to style Button from both web and mobile

(Slack conversation)

There is a pull request that explores primitive UI components that can be used both in native mobile apps and in the browser: There was no specific discussion item attached to this, but it was requested that anyone interested take a look and provide any feedback they have to drive further development.

News roundup

A few links to Gutenberg and JavaScript related news (curated by @nerrad).

WordPress 5.4 dev notes

Other random stuff

#core-js, #javascript