Fix.

node_modules/is-regex/test.js

@@ -0,0 +1,58 @@
+'use strict';
+
+var test = require('tape');
+var isRegex = require('./');
+var hasToStringTag = typeof Symbol === 'function' && typeof Symbol.toStringTag === 'symbol';
+
+test('not regexes', function (t) {
+	t.notOk(isRegex(), 'undefined is not regex');
+	t.notOk(isRegex(null), 'null is not regex');
+	t.notOk(isRegex(false), 'false is not regex');
+	t.notOk(isRegex(true), 'true is not regex');
+	t.notOk(isRegex(42), 'number is not regex');
+	t.notOk(isRegex('foo'), 'string is not regex');
+	t.notOk(isRegex([]), 'array is not regex');
+	t.notOk(isRegex({}), 'object is not regex');
+	t.notOk(isRegex(function () {}), 'function is not regex');
+	t.end();
+});
+
+test('@@toStringTag', { skip: !hasToStringTag }, function (t) {
+	var regex = /a/g;
+	var fakeRegex = {
+		toString: function () { return String(regex); },
+		valueOf: function () { return regex; }
+	};
+	fakeRegex[Symbol.toStringTag] = 'RegExp';
+	t.notOk(isRegex(fakeRegex), 'fake RegExp with @@toStringTag "RegExp" is not regex');
+	t.end();
+});
+
+test('regexes', function (t) {
+	t.ok(isRegex(/a/g), 'regex literal is regex');
+	t.ok(isRegex(new RegExp('a', 'g')), 'regex object is regex');
+	t.end();
+});
+
+test('does not mutate regexes', function (t) {
+	t.test('lastIndex is a marker object', function (st) {
+		var regex = /a/;
+		var marker = {};
+		regex.lastIndex = marker;
+		st.equal(regex.lastIndex, marker, 'lastIndex is the marker object');
+		st.ok(isRegex(regex), 'is regex');
+		st.equal(regex.lastIndex, marker, 'lastIndex is the marker object after isRegex');
+		st.end();
+	});
+
+	t.test('lastIndex is nonzero', function (st) {
+		var regex = /a/;
+		regex.lastIndex = 3;
+		st.equal(regex.lastIndex, 3, 'lastIndex is 3');
+		st.ok(isRegex(regex), 'is regex');
+		st.equal(regex.lastIndex, 3, 'lastIndex is 3 after isRegex');
+		st.end();
+	});
+
+	t.end();
+});