public void ClientRulesWithRegexAttribute() { // Arrange var metadata = ModelMetadataProviders.Current.GetMetadataForProperty(() => null, typeof(string), "Length"); var context = new ControllerContext(); var attribute = new RegularExpressionAttribute("the_pattern"); var adapter = new RegularExpressionAttribute4Adapter(metadata, context, attribute); // Act var rules = adapter.GetClientValidationRules() .OrderBy(r => r.ValidationType) .ToArray(); // Assert Assert.AreEqual(1, rules.Length); Assert.AreEqual("regularExpression", rules[0].ValidationType); Assert.AreEqual(1, rules[0].ValidationParameters.Count); Assert.AreEqual("the_pattern", rules[0].ValidationParameters["pattern"]); Assert.AreEqual(@"The field Length must match the regular expression 'the_pattern'.", rules[0].ErrorMessage); }