CDP Proxy: Allows Other Extensions to Reuse CDP Connection

[swissmanu]

Extends js-debug to expose its internal CDP connection to other extensions.

This pull request resolves #893.

Overview

• A new command requestCDPProxy returns websocket connection details to connect to the CDP proxy.
  • If requestCDPProxy is called the first time, the proxy is created
  • Otherwise connection details for the previously created proxy are returned
• The debug adapter holds an instance of the CDP proxy and ensures forwarding of any communication between proxy clients and the CDP connection.
• The proxy and its clients use a basic JSON communication protocol described here: https://github.com/swissmanu/vscode-js-debug-cdp-proxy-api

[ghost]

All CLA requirements met.

[swissmanu]

Would it make sense to expose the underlying error here https://github.com/microsoft/vscode-js-debug/blob/main/src/cdp/connection.ts#L271, instead of masking it with undefined? This way, users of the CDP proxy could get a concise error message as well.

[connor4312]

Yea, the error should be exposed. I'll play around with it. I would prefer to throw/reject with errors, but we depend on omitting the error in so many places throughout js-debug that changing this would be quite risky.

[connor4312]

@swissmanu can you give me permission to push to your fork please? 🙂

[connor4312]

In the meantime I've pushed my changes onto a branch in 0c6bd3f. As referenced in the commit, I moved the protocol to CDP with a js-debug extension. This simplifies things but it might still be worth publishing a typings package for the js-debug namespace -- right now this is just the single subscribe method but might become more in the future.

Also, now that it's 'just CDP', maybe I should finally look at making js-debug's CDP transports and mechanisms their own package...

[swissmanu]

@swissmanu can you give me permission to push to your fork please? 🙂

I ticked the "Allow edits by maintainers" checkbox on this pull request only. Permissions to the fork should be work by now. Sorry for the delay.

I moved the protocol to CDP with a js-debug extension.

I like like your removal of the additonal protocol layer. Makes things straight forward.

[connor4312]

🚀 Thank you for your work on this!