Typing `module A` at the top of an empty `.res` file causes VSCode to not respond

[fhammerschmidt]

When I create a file called NodeJs.res in a rescript project, and type module A in it, VSCode completely crashes.

I tried to get something meaningful out of the debugger, but there is nothing.

(tested with current master/194bd3a)

[cristianoc]

Would you add some details?
Was that a pre-exiting project, and was "Start Build" pressed? Or was it being build from the outside, or not built at all.
And was the file created from within vscode?

[fhammerschmidt]

It happened in a pre-existing project as well as in a quick rescript inited one where I just created the NodeJs.res within VSCode beside the demo.res. It even crashed with no lib folder created, before any build.

Edit: Ah, but it only happens when rescript-vscode is activated.

[cristianoc]

To rule out an issue with building the extension locally, would you try with the .vsix generated by CI?

[fhammerschmidt]

I already tried it both with the built vsix (rescript-vscode-194bd3a.vsix) as well as locally built.

[cknitt]

Also happens on my machine with the VSIX built from master. Happens with "Node.res", too.

[cknitt]

Actually it does not seem to be related to the filename at all.

[fhammerschmidt]

You are right, it seems the file just needs to be empty and the module ... needs to be the first thing.

[cristianoc]

Can see it now, thanks.

[cristianoc]

Turns out the compact array notation bases on offset used by semantic tokens for speed will crash on an invalid index and bring down the whole thing without any debug info.

Well spotted.

[fhammerschmidt]

Thank you for the fast fix!