37 lines
1.2 KiB
JavaScript
37 lines
1.2 KiB
JavaScript
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'use strict';
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var GetIntrinsic = require('get-intrinsic');
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var $concat = GetIntrinsic('%Array.prototype.concat%');
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var callBind = require('call-bind');
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var callBound = require('call-bind/callBound');
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var $slice = callBound('Array.prototype.slice');
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var hasSymbols = require('has-symbols/shams')();
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var isConcatSpreadable = hasSymbols && Symbol.isConcatSpreadable;
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var empty = [];
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var $concatApply = isConcatSpreadable ? callBind.apply($concat, empty) : null;
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var $concatCall = isConcatSpreadable ? null : callBind($concat, empty);
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var isArray = isConcatSpreadable ? require('isarray') : null;
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module.exports = isConcatSpreadable
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// eslint-disable-next-line no-unused-vars
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? function safeArrayConcat(item) {
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for (var i = 0; i < arguments.length; i += 1) {
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var arg = arguments[i];
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if (arg && typeof arg === 'object' && typeof arg[isConcatSpreadable] === 'boolean') {
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if (!empty[isConcatSpreadable]) {
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empty[isConcatSpreadable] = true;
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}
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var arr = isArray(arg) ? $slice(arg) : [arg];
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arr[isConcatSpreadable] = true; // shadow the property. TODO: use [[Define]]
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arguments[i] = arr;
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}
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}
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return $concatApply(arguments);
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}
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: $concatCall;
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