Debug Server Side code using --inspect

[timofei-iatsenko]

It would be nice to have an option to enable node debugging for server-side code to be able to stop on breakpoints inspect variables and etc.

Proposed syntaxis is:

svelte-kit dev --inspect

Currently, it's possible to start debugger using:

 "dev": "NODE_OPTIONS=\"--inspect\" svelte-kit dev"

This enables inspecting and i successfully connected to the nodejs using Chrome Dev Tools.
But looks like server-side code generated without source maps and it makes it impossible to put breakpoints inside IDE such as Vs Code or Webstorm (they just ignore breakpoints and execute code without stop).

So when --inspect option is set we should pass through this flag to nodejs and enable sourcemaps in all transpilers/vite

[alexbjorlig]

I know it's normally not very nice to add a comment about +1. But I must emphasize how absolute critical debugging is for the developer experience. @thekip is there something I can help with to help with this?

[timofei-iatsenko]

Not for me, i just submitted a feature request. Looks like there is no interest from the maintainer's side, so if you implement this and prepare a PR it would be nice for everyone.

[DylanPiercey]

Looks like this would be solved by vitejs/vite#3928

[mikenikles]

I was curious about that and it turns out it's a few clicks in VS Code to make this work.

I put together a clickable walkthrough at https://twitter.com/mikenikles/status/1495781582996750337.

[timofei-iatsenko]

Debugging with "debugger;" statements was always possible, problem with debugging using breakpoints in ide. The main benefit of IDE breakpoints vs "debugger;" statements you don't need to stop and rebuild/reload current file and don't loose a debugging context.

[Rich-Harris]

I'm not sure that there's anything SvelteKit could do here — by the time you've invoked the svelte-kit CLI, Node is already running. We can't add --inspect retroactively.

It's easy to start the dev server with the inspector without editing the run script:

NODE_OPTIONS="--inspect" npm run dev

Beyond waiting for the Vite PR to get merged is there anything to be done here, or can this issue be closed?

[Nisthar]

NODE_OPTIONS="--inspect" npm run dev

I get Starting inspector on 127.0.0.1:9229 failed: address already in use everytime. Tried changing the port still doesn't work.

[Rich-Harris]

No idea why the port is in use; lsof -i tcp:9229 may help diagnose. Either way, it's not something SvelteKit can help with.

Looks like there's nothing for Kit to do here, so I'll close this

[mathieuhelie]

NODE_OPTIONS="--inspect" npm run dev

I get Starting inspector on 127.0.0.1:9229 failed: address already in use everytime. Tried changing the port still doesn't work.

This may help: I get the same error when adding NODE_OPTIONS from the terminal, but the debugger listens when adding NODE_OPTIONS to the svelte-kit dev script in package.json.

[jayfresh]

The vite PR has been closed without merging - vitejs/vite#3928

[mike-lloyd03]

Is there any current workaround to inspect responses to server-side requests?