55 lines
1.3 KiB
JavaScript
55 lines
1.3 KiB
JavaScript
"use strict";
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var toPosInt = require("../number/to-pos-integer");
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var test = function (arg1, arg2) { return arg2; };
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var desc, defineProperty, generate, mixin;
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try {
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Object.defineProperty(test, "length", {
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configurable: true,
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writable: false,
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enumerable: false,
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value: 1
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});
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}
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catch (ignore) {}
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if (test.length === 1) {
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// ES6
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desc = { configurable: true, writable: false, enumerable: false };
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defineProperty = Object.defineProperty;
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module.exports = function (fn, length) {
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length = toPosInt(length);
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if (fn.length === length) return fn;
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desc.value = length;
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return defineProperty(fn, "length", desc);
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};
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} else {
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mixin = require("../object/mixin");
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generate = (function () {
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var cache = [];
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return function (length) {
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var args, i = 0;
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if (cache[length]) return cache[length];
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args = [];
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while (length--) args.push("a" + (++i).toString(36));
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// eslint-disable-next-line no-new-func
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return new Function(
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"fn",
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"return function (" + args.join(", ") + ") { return fn.apply(this, arguments); };"
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);
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};
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})();
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module.exports = function (src, length) {
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var target;
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length = toPosInt(length);
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if (src.length === length) return src;
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target = generate(length)(src);
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try { mixin(target, src); }
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catch (ignore) {}
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return target;
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};
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}
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