@sequencemedia/css-purge/src/utils/format-font.mjs

A CSS tool written in Node JS as a command line app or library for the purging, burning, reducing, shortening, compressing, cleaning, trimming and formatting of duplicate, extra, excess or bloated CSS.

export default function formatFont (font) {
  const v = font.trim()

  return (
    v.includes(' ') && !(v.startsWith('"') || v.endsWith('"'))
      ? `"${v}"`
      : v
  )
}