Convert IMG tags with SVG files into inline SVG tags

convertImages.js

const convertImages = (query, callback) => {
  const images = document.querySelectorAll(query);

  images.forEach(image => {
    fetch(image.src)
    .then(res => res.text())
    .then(data => {
      const parser = new DOMParser();
      const svg = parser.parseFromString(data, 'image/svg+xml').querySelector('svg');

      if (image.id) svg.id = image.id;
      if (image.className) svg.classList = image.classList;

      image.parentNode.replaceChild(svg, image);
    })
    .then(callback)
    .catch(error => console.error(error))
  });
}