`Data.prototype.toString` may return non-ASCII characters, which aren't accepted by `setHeader`.
E.g., on Russian locale, it might look like this:
```
> new Date().toString()
'Thu Jun 14 2018 13:11:50 GMT+0300 (Финляндия (лето))'
```
This patch introduces `BrowserFetcher` class that manages
downloaded versions of products.
This patch:
- shapes Downloader API to be minimal yet usable for our needs. This
includes removing such methods as `Downloader.supportedPlatforms` and
`Downloader.defaultRevision`.
- makes most of the fs-related methods in Downloader async. The only
exception is the `Downloader.revisionInfo`: it has stay sync due to the
`pptr.executablePath()` method being sync.
- updates `install.js` and `utils/check_availability.js` to use new API
- finally, renames `Downloader` into `BrowserFetcher`
Fixes#1748.
This patch:
- introduces `test/assets/cached` folder and teaches server to cache
all the assets from the folder
- introduces `test/assets/serviceworkers` folder that stores all the
service workers and makes them register with unique URL prefix
- introduces `Response.fromCache()` and `Response.fromServiceWorker()`
methods
Fixes#1551.
This patch:
- resolves pending callbacks in connection once it gets closed
- fixes one of Page.screenshot() tests to wait for all the screenshots
- starts handling ECONNRESET error in test server to avoid throwing with no
good reason
This patch changes Page.navigate API:
- Page.navigate now resolves to the main page response
- Page.navigate throws errors if there's no main page response,
e.g. in case of SSL errors, max navigation timeout,
or invalid url.
This patch also adds httpsServer with a self-signed certificates
for the testing purposes.
Fixes#10.
