This pull request introduces initial support for the WebDriver BiDi
protocol in Playwright. The primary goal of this PR is not to fully
implement BiDi but to experiment with the current state of the
specification and its implementation. We aim to identify the biggest
gaps and challenges that need to be addressed before considering BiDi as
the main protocol for Playwright.
This patch implements a new mode of network tethering for Playwright
server & its clients.
With this patch:
- playwright server could be launched with the
`--browser-proxy-mode=tether` flag to engage in the new mode
- a new type of client, "Network Tethering Client" can connect to the
server to provide network traffic to the browsers
- all clients that connect to the server with the `x-playwright-proxy:
*` header will get traffic from the "Network Tethering Client"
This patch also adds an environment variable
`PW_OWNED_BY_TETHER_CLIENT`. With this env, playwright server will
auto-close when the network tethering client disconnects. It will also
auto-close if the network client does not connect to the server in the
first 10 seconds of the server existence. This way we can ensure that
`npx playwright docker start` blocks terminal & controls the lifetime of
the started container.