40 lines
1000 B
JavaScript
40 lines
1000 B
JavaScript
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'use strict';
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var has = require('has');
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var regexExec = RegExp.prototype.exec;
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var gOPD = Object.getOwnPropertyDescriptor;
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var tryRegexExecCall = function tryRegexExec(value) {
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try {
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var lastIndex = value.lastIndex;
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value.lastIndex = 0; // eslint-disable-line no-param-reassign
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regexExec.call(value);
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return true;
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} catch (e) {
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return false;
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} finally {
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value.lastIndex = lastIndex; // eslint-disable-line no-param-reassign
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}
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};
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var toStr = Object.prototype.toString;
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var regexClass = '[object RegExp]';
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var hasToStringTag = typeof Symbol === 'function' && typeof Symbol.toStringTag === 'symbol';
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module.exports = function isRegex(value) {
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if (!value || typeof value !== 'object') {
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return false;
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}
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if (!hasToStringTag) {
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return toStr.call(value) === regexClass;
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}
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var descriptor = gOPD(value, 'lastIndex');
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var hasLastIndexDataProperty = descriptor && has(descriptor, 'value');
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if (!hasLastIndexDataProperty) {
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return false;
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}
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return tryRegexExecCall(value);
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};
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