webp-support.ts

export let hasWebPSupport = null;
export const loadImgSrc(src: string): Promise<void> {
  return new Promise((resolve, reject) => {
    const img = new Image();
    img.onload = () => resolve();
    img.onerror = () => reject();
    img.src = src;
  });
}
export const checkWebPSupport = () => {
  if (typeof hasWebPSupport === 'boolean') return;
  // lifted from modernizer src
  return loadImageSrc('data:image/webp;base64,UklGRkoAAABXRUJQVlA4WAoAAAAQAAAAAAAAAAAAQUxQSAwAAAABBxAR/Q9ERP8DAABWUDggGAAAADABAJ0BKgEAAQADADQlpAADcAD++/1QAA==')
    .then(() => {
      hasWebPSupport = true;
    })
    .catch(() => {
      hasWebPSupport = false;
    });
};