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