Improve support for debugging

[jamesopstad]

Confirm that VSCode can use breakpoints in Workers. Document how to enable this.

[dario-piotrowicz]

Quick update on the situation

I've started looking at the debugging situation here

I've applied (to the main code currently at 91ca74) an inspectorPort to the getDevMiniflareOptions and getPreviewMiniflareOptions methods:

And slightly modified the worker playground app:

When I run the application (pnpm dev) I can successfully connect my vscode (using the configuration mentioned in our documentation) to the workerd process inspector:

But strangely vscode does not then stop at the debugger statement I added, so this is currently not working as expected (I am pretty sure that this at some point was working)¹.

Using chrome I can however go to chrome://inspect and find various workers I can connect to:

Among those I can select the user one workerd: worker core:user:worker and then the debugger statement is correctly encountered, I can also step through, see typescript original code, see the various variable values, etc... everything seems to be working as expected here:

Footnotes

1. I double checked and wrangler (which uses the same version of miniflare we do: 3.20241205.0) doesn't seem to have any issue with attaching vscode to the worker and stopping at a debugger statement, suggesting that something is wrong on our side:
   ↩

[dario-piotrowicz]

The same applies for the multi-worker app:

Naturally with a few more workers to chose from in the chrome inspect page:

Warning

When I started debugging the multi-worker app I encountered some connection lost errors, after restarting pnpm dev they seem to have disappeared, but I think there's an issue around this, I'll need to keep an eye out for this

[jamesopstad]

Moved to cloudflare/workers-sdk#7852.