27 lines
790 B
TypeScript
27 lines
790 B
TypeScript
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const polyfill = () => {
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if (!Array.prototype.at) {
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// Taken from https://github.com/tc39/proposal-relative-indexing-method#polyfill so that it works in tests
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/* eslint-disable */
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Object.defineProperty(Array.prototype, "at", {
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value: function (n: number) {
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// ToInteger() abstract op
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n = Math.trunc(n) || 0;
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// Allow negative indexing from the end
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if (n < 0) {
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n += this.length;
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}
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// OOB access is guaranteed to return undefined
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if (n < 0 || n >= this.length) {
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return undefined;
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}
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// Otherwise, this is just normal property access
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return this[n];
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},
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writable: true,
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enumerable: false,
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configurable: true,
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});
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}
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};
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export default polyfill;
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