masto-fe/app/javascript/mastodon/load_polyfills.js
Yamagishi Kazutoshi 0758b00bfd Refactor resizeImage method (#7236)
- Use URL.createObjectURL (replace from FileReader)
- Use HTMLCanvasElement.prototype.toBlob
  (replace from HTMLCanvasElement.prototype.toDataURL)
- Use Promise (replace callback interface)
2018-04-23 09:15:51 +02:00

41 lines
1.3 KiB
JavaScript

// Convenience function to load polyfills and return a promise when it's done.
// If there are no polyfills, then this is just Promise.resolve() which means
// it will execute in the same tick of the event loop (i.e. near-instant).
function importBasePolyfills() {
return import(/* webpackChunkName: "base_polyfills" */ './base_polyfills');
}
function importExtraPolyfills() {
return import(/* webpackChunkName: "extra_polyfills" */ './extra_polyfills');
}
function loadPolyfills() {
const needsBasePolyfills = !(
Array.prototype.includes &&
HTMLCanvasElement.prototype.toBlob &&
window.Intl &&
Number.isNaN &&
Object.assign &&
Object.values &&
window.Symbol
);
// Latest version of Firefox and Safari do not have IntersectionObserver.
// Edge does not have requestIdleCallback and object-fit CSS property.
// This avoids shipping them all the polyfills.
const needsExtraPolyfills = !(
window.IntersectionObserver &&
window.IntersectionObserverEntry &&
'isIntersecting' in IntersectionObserverEntry.prototype &&
window.requestIdleCallback &&
'object-fit' in (new Image()).style
);
return Promise.all([
needsBasePolyfills && importBasePolyfills(),
needsExtraPolyfills && importExtraPolyfills(),
]);
}
export default loadPolyfills;