Fixed deserializing ObservableCollection in .NET Core 2.0 (#1353)

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

@@ -1085,6 +1085,20 @@ namespace Newtonsoft.Json.Tests.Serialization
             Assert.AreEqual("1", s[0]);
             Assert.AreEqual("2", s[1]);
         }
+
+        [Test]
+        public void SerializeObservableCollection()
+        {
+            ObservableCollection<string> c1 = new ObservableCollection<string> { "1", "2" };
+
+            string output = JsonConvert.SerializeObject(c1);
+            Assert.AreEqual("[\"1\",\"2\"]", output);
+
+            ObservableCollection<string> c2 = JsonConvert.DeserializeObject<ObservableCollection<string>>(output);
+            Assert.AreEqual(2, c2.Count);
+            Assert.AreEqual("1", c2[0]);
+            Assert.AreEqual("2", c2[1]);
+        }
 #endif
 
         [Test]

Src/Newtonsoft.Json/Serialization/DefaultContractResolver.cs

@@ -881,7 +881,7 @@ namespace Newtonsoft.Json.Serialization
             }
         }
 
-        private static bool IsConcurrentCollection(Type t)
+        private static bool IsConcurrentOrObservableCollection(Type t)
         {
             if (t.IsGenericType())
             {
@@ -893,6 +893,7 @@ namespace Newtonsoft.Json.Serialization
                     case "System.Collections.Concurrent.ConcurrentStack`1":
                     case "System.Collections.Concurrent.ConcurrentBag`1":
                     case "System.Collections.Concurrent.ConcurrentDictionary`2":
+                    case "System.Collections.ObjectModel.ObservableCollection`1":
                         return true;
                 }
             }
@@ -903,7 +904,7 @@ namespace Newtonsoft.Json.Serialization
         private static bool ShouldSkipDeserialized(Type t)
         {
             // ConcurrentDictionary throws an error in its OnDeserialized so ignore - http://json.codeplex.com/discussions/257093
-            if (IsConcurrentCollection(t))
+            if (IsConcurrentOrObservableCollection(t))
             {
                 return true;
             }
@@ -920,7 +921,7 @@ namespace Newtonsoft.Json.Serialization
 
         private static bool ShouldSkipSerializing(Type t)
         {
-            if (IsConcurrentCollection(t))
+            if (IsConcurrentOrObservableCollection(t))
             {
                 return true;
             }