Weird behavior while logging blank exports (Svelte)

[012e]

Reproduce

1. Create a project normally
2. Create any route

bud new controller hello:/ index show

3. bud run
4. Add console.log(hellos); in the script tag (index.svelte)
5. Go to http://127.0.0.1:3000/ and we will see an error message. For the first time:

gob: bad data: field numbers out of bounds

• Reload. For the second time:

• What the terminal looks like:

• More details:

  • The error message varies between reloads
  • Remove console.log(hellos); doesn't fix the problem unless I bud run again

• OS: Arch linux

• Go: v1.18.2

• Node: v14.19.3

• bud: 0.1.4

Edit: app made with bud build works normally.

[matthewmueller]

Thanks for reporting @012e! I haven't confirmed but I can see how this could be an issue. Can you quickly test if this occurs on an app generated with bud build?

bud build
./bud/app
open http://localhost:3000

I'm going to assume that the console.log("hellos") works as expected when using bud build.

I believe the problem is two-fold:

1. console.log to stdout support was added to the V8 package. This is mighty convenient for debugging. You can test this with:

   echo "console.log('hi')" | bud tool v8

2. The v8client is used to avoid needing to recompile V8 for every change to a Go file. What this does is from your development app it will start the bud tool v8 client server¹ to evaluate JS using the V8 pre-built into Bud. This operates over stdio through a bare-bones protocol.

The problem seems to be that the console logs getting logged to stdout are interfering with the data sent over the protocol.

I'm currently reworking the V8 client to not need to know where the bud binary is, so I'll work on fixing this in that push.

Footnotes

1. bud tool v8 client is misnamed and should be called bud tool v8 server because it's serving eval requests. ↩

[ldlac]

Not sure if it's related but localStorage, window, document, setInterval, etc have a weird behavior too.

view: render error ReferenceError: setInterval is not defined

when wrapped inside a if (typeof document != "undefined") or anything that v8 will appreciate, everything is fine, console.log included

[matthewmueller]

Hey @ldlac, I just moved your comment into another issue since it's a separate problem. Please have a look at my response there! I'm going to hide your comment (and mine too after you see this) since I'd like us to chat about it in that issue!