That's really cool, well architectured.
It would be great if we could switch to such a setup and profit from your work. The main challenge is of course that we would rely on a code base that is all owned by volar. I'll bring it up for discussion with the team here and we see what can be done.

This would be great to have - was there any decision by the team?

If anyone wants to test this, you can find the preview extension here: johnsoncodehk#1

👋🏽 Hello and thank you for this work. I've been using it for a few weeks and it is a nice improvement over the existing builtin.

One issue I've stumbled upon is with this type of construct, in a ./templates/a_component.html file:

<script>
     import {mySymbol} from "myLib";
     // ....
</script>

Where myLib is declared as an alias in tsconfig.json .

VSCode gives me this output

Cannot find module 'myLib'. Did you mean to set the 'moduleResolution' option to 'nodenext', or to add aliases to the 'paths' option?

My ./tsconfig.json looks like:

{
    "compilerOptions": {
        "baseUrl": "./",
        "allowJs": true,
        "checkJs": true,
        "paths": {
            "myLib": [
                "./assets/js/mylib.js"
            ]
        },
        "noEmit": true
    },
    "exclude": [
        "**/*node_modules"
    ]
}

The extension doesn't seem to pick up the tsconfig.json. I've read through the diff and the issue seems to be that the compiler options are hard-coded (here).

Do you think it could be possible to merge that config with a tsconfig.json found in the current file's directories ancestors?

Again, thanks for this work, it make working with good old plain HTML a nice experience.

@dbarbeau Identifying the tsconfig file might break past expected behavior. It's better to first open an issue to ensure this behavior is acceptable.

On the other hand, in the old implementation, TS2792 was hardcoded to be ignored, and we need to replicate this in the new implementation: https://github.com/microsoft/vscode/pull/171547/files#diff-59eb51223528724f029725ed9e90b92046cde69ea26e07e8059fd4f349a320e5L102-L105