tool/updateFrontMatter.js

const fs = require('fs');
const globby = require('globby');
const matter = require('gray-matter');
const path = require('path');

async function update(root) {
    const baseDir = __dirname + '/../public/' + root + '/';

    const files = await globby([baseDir + '*.js']);

    for (let file of files) {
        const fileName = path.basename(file);
        const code = fs.readFileSync(file, 'utf-8');
        if (matter.test(code, {
            delimiters: ['/*', '*/']
        })) {
            continue;
        }

        const mdContent = fs.readFileSync(baseDir + 'meta/' + fileName.replace(/.js$/, '.md'), 'utf-8');

        const res = matter(mdContent);
        const comment = matter.stringify('', res.data, {
            delimiters: ['/*', '*/']
        });

        fs.writeFileSync(file, comment + code, 'utf-8');
    }
}

update('data').then(() => {
    update('data-gl');
});