文档：fonts 属性

document.fonts.ready.then((fontFaceSet) => {
  // Any operation that needs to be done only after all used fonts
  // have finished loading can go here.
  const fontFaces = [...fontFaceSet];
  console.log(fontFaces);
  // some fonts may still be unloaded if they aren't used on the site
  console.log(fontFaces.map((f) => f.status));
});