* chore: run unit tests on node 10.15
We saw in https://github.com/puppeteer/puppeteer/issues/6548 that the
`fs.promises` module was experimental in Node <10.17 and as such we
introduced issues for users on 10.15.
Until we can drop Node v10 (it's EOL is 30-04-20201
https://github.com/nodejs/Release#release-schedule) we should run our
tests on an old Node 10 to avoid regressing in this area.
* chore: helper for importing fs safely
* chore(agnostification): common/helper.ts
The `readProtocolStream` method uses `fs` only if you want to write to a
file. So we gate at the start of the function and ensure that if we got
given a path we are not in a Node environment.
In `src/common` we now use `fs.promises.X` which we can dynamically
`import`. In a browser environment this code will never run because it's
gated on `isNode` (in a future PR we will add tree-shaking to the bundle
step such that this code is eliminated). By using `import`, we ensure
TypeScript still can track types and give good type information.
In `src/node` we continue to use `util.promisify` but that's not a
concern as that code explicitly is never run in the browser.
* chore: enforce file extensions on imports
To make our output agnostic it should include file extensions in the
output, as per the ESM spec. It's a bit odd for Node packages but makes
it easier to publish a browser build.
* chore: Use devtools-protocol package
Rather than maintain our own protocol we can instead use the devtools-protocol package and pin it to the version of Chromium that Puppeteer is shipping with.
The only changes are naming changes between the bespoke protocol that Puppeteer created and the devtools-protocol one.
* chore: remove `installAsyncStackHooks` helper
This code was written when browsers/Node didn't support errors in async
functions very well. They now do a much better job of this, so we can
lose the additonal complexity from our codebase and leave it to the host
environment :)
* lazy launcher is private
* remove async stack test
These files will be used by both the web and node versions of Puppeteer.
Another name for this might be "core" but I don't want to cause
confusion with the puppeteer-core package that we publish at the moment.
