Fix missing error when deserializing JToken with a contract type mismatch (#2494)

Author: JamesNK

Src/Newtonsoft.Json.Tests/Issues/Issue2484.cs

@@ -0,0 +1,55 @@
+#region License
+// Copyright (c) 2007 James Newton-King
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the "Software"), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+#endregion
+
+#if (NET45 || NET50)
+#if DNXCORE50
+using Xunit;
+using Test = Xunit.FactAttribute;
+using Assert = Newtonsoft.Json.Tests.XUnitAssert;
+#else
+using NUnit.Framework;
+#endif
+using System.Collections.Generic;
+using Newtonsoft.Json.Serialization;
+using Newtonsoft.Json.Converters;
+using System.Collections;
+using System;
+using Newtonsoft.Json.Linq;
+
+namespace Newtonsoft.Json.Tests.Issues
+{
+    [TestFixture]
+    public class Issue2484
+    {
+        [Test]
+        public void Test()
+        {
+            var json = "[]";
+            var ex = ExceptionAssert.Throws<JsonSerializationException>(() => JsonConvert.DeserializeObject(json, typeof(JObject)));
+            Assert.AreEqual("Deserialized JSON type 'Newtonsoft.Json.Linq.JArray' is not compatible with expected type 'Newtonsoft.Json.Linq.JObject'. Path '', line 1, position 2.", ex.Message);
+        }
+    }
+}
+#endif

Src/Newtonsoft.Json.Tests/Serialization/JsonSerializerTest.cs

@@ -3515,13 +3515,9 @@ public void CannotDeserializeArrayIntoLinqToJson()
         {
             string json = @"[]";
 
-            ExceptionAssert.Throws<InvalidCastException>(
+            ExceptionAssert.Throws<JsonSerializationException>(
                 () => { JsonConvert.DeserializeObject<JObject>(json); },
-                new[]
-                {
-                    "Unable to cast object of type 'Newtonsoft.Json.Linq.JArray' to type 'Newtonsoft.Json.Linq.JObject'.",
-                    "Cannot cast from source type to destination type." // mono
-                });
+                "Deserialized JSON type 'Newtonsoft.Json.Linq.JArray' is not compatible with expected type 'Newtonsoft.Json.Linq.JObject'. Path '', line 1, position 2.");
         }
 
         [Test]

Src/Newtonsoft.Json/Serialization/JsonSerializerInternalReader.cs

@@ -238,6 +238,15 @@ private JsonSerializerProxy GetInternalSerializer()
                 token = writer.Token;
             }
 
+            if (contract != null && token != null)
+            {
+                if (!contract.UnderlyingType.IsAssignableFrom(token.GetType()))
+                {
+                    throw JsonSerializationException.Create(reader, "Deserialized JSON type '{0}' is not compatible with expected type '{1}'."
+                        .FormatWith(CultureInfo.InvariantCulture, token.GetType().FullName, contract.UnderlyingType.FullName));
+                }
+            }
+
             return token;
         }