adds regex helpers

lib/regex.js

@@ -0,0 +1,50 @@
+'use strict';
+
+var util = require('handlebars-utils');
+var utils = require('./utils');
+var helpers = module.exports;
+
+/**
+ * Convert the given string to a regular expression.
+ *
+ * ```handlebars
+ * {{toRegex "foo"}}
+ * //=> /foo/
+ * ```
+ * @param {String} `str`
+ * @return {RegExp}
+ * @api public
+ */
+
+helpers.toRegex = function(str, locals, options) {
+  var opts = util.options({}, locals, options);
+  return new RegExp(str, opts.flags);
+};
+
+/**
+ * Returns true if the given `str` matches the given regex. A regex can
+ * be passed on the context, or using the [toRegex](#toregex) helper as a
+ * subexpression.
+ *
+ * ```handlebars
+ * {{test "bar" (toRegex "foo")}}
+ * //=> false
+ * {{test "foobar" (toRegex "foo")}}
+ * //=> true
+ * {{test "foobar" (toRegex "^foo$")}}
+ * //=> false
+ * ```
+ * @param {String} `str`
+ * @return {RegExp}
+ * @api public
+ */
+
+helpers.test = function(str, regex) {
+  if (!util.isString(str)) {
+    return false;
+  }
+  if (!utils.typeOf(regex) === 'regexp') {
+    throw new TypeError('expected a regular expression');
+  }
+  return regex.test(str);
+};