feat: make it possible to run install.js script with puppeteer-core

[gziolo]

Problem

At the moment, when you set puppeteer-core as a dependency of your project, you won't have Chromium installed as part of npm install run. This is great. However, the existing setup prevents 3rd party tools to run install.js script, which might be desired in some scenarios.

We see the growing number of complaints about Chromium download in @wordpress/scripts (A set of reusable scripts tailored for WordPress development) package which for many use cases is not necessary when you don’t want to use e2e tests. Some projects decide to not use this package because of the time and size factors introduced by the installation process of Chromium. We are seeking for a way to make it a non-issue. The idea is to use puppeteer-core and use install.js script only when someone opts-in for the e2e script and actually runs it.

Related Issues

Sharing some issues from the WordPress project, which triggered this proposal:

• Scripts: Download Puppeteer's Chromium binary on-demand
• Scripts: Defer installation of dependencies until they are used for the first time
• Build: Remove chromium install from common flows

Solution

Update utils/prepare_puppeteer_core.js to remove install from script section package.json for puppeteer-core. This is nearly identical to the current configuration but opens install.js for usage from puppeteer-core. At the same time, it would become a public API, so the project would have to maintain it.

It will allow starting using puppeteer-core as a dependency in the @wordpress/scripts package intended to offer zero-config reusable scripts for WordPress development. This way, folks who don't use Puppeteer in their workflows won't complain about the install process of Chromium. Instead, it should be possible to install Chromium on demand, when the script which needs it would run for the first time. The update could run whenever the version changes as part of the regular run as well.

The only inconvenience would be that other dependency which set puppeteer as a peer dependency would warn. Still, it's something that can be ignored and listed in the docs in the troubleshooting section.

Open Question

Should the same change get applied to puppeteer-firefox? I see this guard clause:

puppeteer/experimental/puppeteer-firefox/install.js

Lines 19 to 20 in 14b2369

	if (require('./package.json').name === 'puppeteer-core')
	return;

However, it's not clear for me how it would work with puppeteer-core.

[mathiasbynens]

As you point out, this makes install.js a public API. Please add a comment to the top of install.js pointing this out. Other than that this LGTM. Thanks for the patch!

[gziolo]

As you point out, this makes install.js a public API. Please add a comment to the top of install.js pointing this out.

Added with 601a571 👍