30 lines
1.3 KiB
JavaScript
30 lines
1.3 KiB
JavaScript
'use strict';
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var $ = require('../internals/export');
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var uncurryThis = require('../internals/function-uncurry-this');
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var $isCallable = require('../internals/is-callable');
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var inspectSource = require('../internals/inspect-source');
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var hasOwn = require('../internals/has-own-property');
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var DESCRIPTORS = require('../internals/descriptors');
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// eslint-disable-next-line es/no-object-getownpropertydescriptor -- safe
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var getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor;
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var classRegExp = /^\s*class\b/;
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var exec = uncurryThis(classRegExp.exec);
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var isClassConstructor = function (argument) {
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try {
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// `Function#toString` throws on some built-it function in some legacy engines
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// (for example, `DOMQuad` and similar in FF41-)
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if (!DESCRIPTORS || !exec(classRegExp, inspectSource(argument))) return false;
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} catch (error) { /* empty */ }
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var prototype = getOwnPropertyDescriptor(argument, 'prototype');
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return !!prototype && hasOwn(prototype, 'writable') && !prototype.writable;
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};
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// `Function.isCallable` method
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// https://github.com/caitp/TC39-Proposals/blob/trunk/tc39-reflect-isconstructor-iscallable.md
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$({ target: 'Function', stat: true, sham: true, forced: true }, {
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isCallable: function isCallable(argument) {
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return $isCallable(argument) && !isClassConstructor(argument);
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}
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});
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