Fixed validation of JTokens with type Uri

src/NJsonSchema.Tests/Validation/FormatUriTests.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Linq;
 using Newtonsoft.Json.Linq;
 using NJsonSchema.Validation;
@@ -40,5 +41,22 @@ public void When_format_uri_correct_then_validation_succeeds()
             //// Assert
             Assert.Empty(errors);
         }
+
+        [Fact]
+        public void When_uri_token_is_of_type_uri_then_validation_succeeds()
+        {
+            //// Arrange
+            var schema = new JsonSchema();
+            schema.Type = JsonObjectType.String;
+            schema.Format = JsonFormatStrings.Uri;
+
+            var token = new JValue(new Uri("http://rsuter.com"));
+
+            //// Act
+            var errors = schema.Validate(token);
+
+            //// Assert
+            Assert.Empty(errors);
+        }
     }
 }

src/NJsonSchema/Validation/JsonSchemaValidator.cs

@@ -222,7 +222,23 @@ private void ValidateString(JToken token, JsonSchema schema, JsonObjectType type
 
             if (isString)
             {
-                var value = token.Type == JTokenType.Date ? (token as JValue).ToString("yyyy-MM-ddTHH:mm:ssK") : token.Value<string>();
+                string value;
+
+                switch (token.Type)
+                {
+                    case JTokenType.Date:
+                        value = (token as JValue)?.ToString("yyyy-MM-ddTHH:mm:ssK");
+                        break;
+
+                    case JTokenType.Uri:
+                        value = (token as JValue)?.ToString();
+                        break;
+
+                    default:
+                        value = token.Value<string>();
+                        break;
+                }
+
                 if (value != null)
                 {
                     if (!string.IsNullOrEmpty(schema.Pattern))