src/assets.js
function scss(source: string, dest: string): Promise {
  return new Promise((resolve, reject) => {
    sass.render(
      {
        file       : source,
        outFile    : dest,
        outputStyle: 'compressed',
      },
      (err, result) => {
        if (err) reject(err);
        fs.ensureFile(dest).then(fs.writeFile(dest, result.css)).then(resolve).catch(reject);
      },
    );
  });
}
function scss(source: string, dest: string): Promise {
  return new Promise((resolve, reject) => {
    sass.render(
      {
        file       : source,
        outFile    : dest,
        outputStyle: 'compressed',
      },
      (err, result) => {
        if (err) reject(err);
        fs.ensureFile(dest).then(fs.writeFile(dest, result.css)).then(resolve).catch(reject);
      },
    );
  });
}
Compile scss assets