We currently download Chrome/Firefox immediately on `npm install`
invocations because Puppeteer's postinstall script does that by default.
However, this is wasteful if the user/workflow doesn't actually need to
run Puppeteer or its browsers, for example in GitHub Actions workflows
that do linting, static analysis or other tasks like updating locales or
publishing artifacts.
This commit therefore makes sure no browser binaries get pulled in by
default anymore, and defers doing that until it's actually necessary,
which is when we want to start the browsers in the `startBrowsers`
function of `test.mjs`.
Locally this brings the `npm install` runtime down from 8.998 to 1.800
seconds, and as a bonus it results in better log output too because it
now shows which browser versions were used in the run (whereas
previously with `npm install` this information was not sent to stdout).
We currently use the pinned version of Chrome as hardcoded in the
Puppeteer release, which is based on the version of Chrome that was
deemed stable at the time of the Puppeteer release.
However, this is not ideal because it means that Chrome updates are
strongly tied to Puppeteer releases, so if Puppeteer releases are slow
we could be missing out on e.g. (security) patches being applied on the
stable channel. It's also not consistent with Firefox where we don't
use a hardcoded pinned version either.
This commit therefore configures Puppeteer to use (resolve) the most
recent stable version of Chrome at the time of the installation so that
determining the browser version to use is fully decoupled from the
Puppeteer release we're running.
The effect of this change can be seen in the output of running
`npx puppeteer browsers list`:
Before:
`chrome@149.0.7827.22 (linux) <path>`
After (note the slightly newer version):
`chrome@149.0.7827.115 (linux)` <path>`
Nowadays Chrome has a built-in (new) headless mode in the regular
binary, but before that time there was an old headless mode that was
essentially a separate binary [1]. We don't use the latter, but it turns
out that Puppeteer downloads it automatically if it's not explicitly
skipped, which is wasteful because it costs extra time and resources for
each `npm install` invocation.
This commit therefore skips downloading Chrome headless shell explictly,
which results in the local runtime of `npm install` going from 10.125
seconds to 8.998 seconds (which can't hurt in e.g. GitHub Actions).
[1] https://developer.chrome.com/blog/chrome-headless-shell.
This is a major version bump, but the changelog at
https://github.com/puppeteer/puppeteer/releases/tag/puppeteer-core-v25.0.0
doesn't indicate any breaking changes that should impact us.
Moreover, this release contains the fix for the memory leak from
puppeteer/puppeteer#14876, so we can remove
the workaround related to that now.
Finally, we rename `.puppeteerrc` to `.puppeteerrc.json` because of
https://github.com/puppeteer/puppeteer/issues/15076, but in general it's
a good idea to be explicit about the file format via its extension, so
even if this upstream bug is fixed we don't need to revert this.
