gatsby-browser.js

// /**
//  * Implement Gatsby's Browser APIs in this file.
//  *
//  * See: https://www.gatsbyjs.org/docs/browser-apis/
//  */

// // You can delete this file if you're not using it
exports.onClientEntry = () => {
  // IntersectionObserver polyfill for gatsby-image (Safari, IE)
  if (typeof window.IntersectionObserver === `undefined`) {
    import(`intersection-observer`);
    console.log(`👍 IntersectionObserver is polyfilled`);
  }

  // Object-fit/Object-position polyfill for gatsby-image (IE)
  const testImg = document.createElement(`img`);
  if (
    typeof testImg.style.objectFit === `undefined` ||
    typeof testImg.style.objectPosition === `undefined`
  ) {
    import(`object-fit-images`)();
    console.log(`👍 Object-fit/Object-position are polyfilled`);
  }
};