* chore: Don't store revisions in `package.json`
It's quite messy to have to require the `package.json` file in multiple
places purely to find out what revision of a given browser we want to
use. We can also achieve better type safety by placing it in an actual
source file.
This commit makes that change and also tidies up our reliance on
`package.json` within the source code generally; we now only use it to
find the location of the Puppeteer root such that we know where to
install downloaded browsers to.
To avoid using `package.json` to parse the name of the module, we also
now explicitly have an entry point for the Puppeteer module and the
Puppeter Core module. This will make it easier in the future to ship
less code as part of core (e.g. core never needs to download a browser,
so why ship that code?). Core can also then not have any revisions based
info contained in it.
The test install script has also been updated to ensure that
puppeteer-core can be installed correctly too.
Finally, the `install` script has been moved to TypeScript for nicer
typechecking and safety. The functionality of it has not changed.
* chore(agnostic): ship CJS and ESM builds
For our work to enable Puppeteer in other environments (e.g. a browser)
we need to ship an ESM build. This commit changes our config to ship to
`lib/cjs` and `lib/esm` accordingly. The majority of our code stays the
same, with one small fix for the CJS build to ensure that we ship a
version that lets you `require('puppeteer')` rather than have to
`require('puppeteer').default`. We do this with the `cjs-entry.js` which
is what the `main` field in our `package.json` points to.
We also swap to `read-pkg-up` to find the `package.json` file. This is
because the folder structure of `lib/` does not match `src/` now we ship
to `cjs` and `esm`, so you cannot rely on exact paths. This module works
up from the file to find the nearest `package.json` so it will always
find Puppeteer's `package.json`.
Note that we *do not* point any users to the ESM build. We happen to
ship those files so people who know about them can get at them but it's
not expected (nor will we actively support) that people will rely on
them. The CommonJS build is considered our main build.
We may make breaking changes to the structure of the ESM build which we
will do without requiring new major versions. For example the ESM build
currently ships all files that the CJS build does, but given we are
working on the ESM build being able to run in the browser this may
change over time.
Long term once the Node versions catch up we can ditch CJS and ship
exclusively ESM but we are not there yet.
* chore: add test for npm package installing correctly
This command packs up the module and installs it again to check we're
correctly bundling everything we need to allow users to do a fresh
install.
* install realpath
