sass-embedded issue

index.js

const fs = require('fs');
const path = require('path');
const dartSass = require('sass');
const dartEmbedded = require('sass-embedded');

const dartJson = path.resolve('./dist/dart.json');
const embeddedJson = path.resolve('./dist/embedded.json');

const srcFile = path.resolve('./scss/resolve-vars.scss');

function resolveVars(compiler, src, dest ) {
    let content = {};

    compiler.compile( src,  {
        functions: {
            'resolve-var($key, $type, $value)': (args) => {
                const _key = args[0].toString();
                const _type = args[1].toString();
                const _val = args[2].toString();

                console.log( _key, _type, _val );

                content[_key] = {
                    type: _type,
                    value: _val
                };

                return new compiler.SassString('');
            }
        },
        logger: compiler.Logger.silent
    });

    fs.writeFileSync( dest, JSON.stringify( content, null, 4 ) );
}

function resolveDart() {
    resolveVars( dartSass, srcFile, dartJson );
}
resolveDart();

function resolveEmbedded() {
    resolveVars( dartEmbedded, srcFile, embeddedJson );
}
resolveEmbedded();

resolve-vars.scss

@use "sass:meta";
@use "vars.scss";

$_vars: meta.module-variables("vars");

body {
    @each $key, $val in $_vars {
        var: resolve-var( unquote($key), meta.type-of( $val ), $val );
    }
}

vars.scss

$var-a: 3;
// $var-b: calc( 4px + 3em );