summaryrefslogtreecommitdiffstats
path: root/node_modules/is-regex/index.js
diff options
context:
space:
mode:
Diffstat (limited to 'node_modules/is-regex/index.js')
-rw-r--r--node_modules/is-regex/index.js58
1 files changed, 58 insertions, 0 deletions
diff --git a/node_modules/is-regex/index.js b/node_modules/is-regex/index.js
new file mode 100644
index 0000000..3db4b92
--- /dev/null
+++ b/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;
+ };