Commit

1 files changed, 58 insertions, 0 deletions

diff --git a/src/node_modules/is-regex/index.js b/src/node_modules/is-regex/index.js
new file mode 100644
index 0000000..3db4b92
--- /dev/null
+++ b/src/node_modules/is-regex/index.js
@@ -0,0 +1,58 @@
+'use strict';
+
+var hasSymbols = require('has-symbols')();
+var hasToStringTag = hasSymbols && typeof Symbol.toStringTag === 'symbol';
+var hasOwnProperty;
+var regexExec;
+var isRegexMarker;
+var badStringifier;
+
+if (hasToStringTag) {
+	hasOwnProperty = Function.call.bind(Object.prototype.hasOwnProperty);
+	regexExec = Function.call.bind(RegExp.prototype.exec);
+	isRegexMarker = {};
+
+	var throwRegexMarker = function () {
+		throw isRegexMarker;
+	};
+	badStringifier = {
+		toString: throwRegexMarker,
+		valueOf: throwRegexMarker
+	};
+
+	if (typeof Symbol.toPrimitive === 'symbol') {
+		badStringifier[Symbol.toPrimitive] = throwRegexMarker;
+	}
+}
+
+var toStr = Object.prototype.toString;
+var gOPD = Object.getOwnPropertyDescriptor;
+var regexClass = '[object RegExp]';
+
+module.exports = hasToStringTag
+	// eslint-disable-next-line consistent-return
+	? function isRegex(value) {
+		if (!value || typeof value !== 'object') {
+			return false;
+		}
+
+		var descriptor = gOPD(value, 'lastIndex');
+		var hasLastIndexDataProperty = descriptor && hasOwnProperty(descriptor, 'value');
+		if (!hasLastIndexDataProperty) {
+			return false;
+		}
+
+		try {
+			regexExec(value, badStringifier);
+		} catch (e) {
+			return e === isRegexMarker;
+		}
+	}
+	: function isRegex(value) {
+		// In older browsers, typeof regex incorrectly returns 'function'
+		if (!value || (typeof value !== 'object' && typeof value !== 'function')) {
+			return false;
+		}
+
+		return toStr.call(value) === regexClass;
+	};