Merge pull request #127 from WalletConnect/feat/ensure-type-is-valid

feat: add type safe check when sending custom request / response types

Core Modules/WalletConnectSharp.Common/Utils/TypeSafety.cs

@@ -0,0 +1,27 @@
+using Newtonsoft.Json;
+
+namespace WalletConnectSharp.Common.Utils;
+
+public static class TypeSafety
+{
+    private static JsonSerializerSettings Settings =
+        new JsonSerializerSettings() { TypeNameHandling = TypeNameHandling.Auto };
+
+    public static void EnsureTypeSerializerSafe<T>(T testObject)
+    {
+        // unwrapping and rewrapping the object
+        // to / from JSON should tell us
+        // if it's serializer safe, since
+        // we are using the serializer to test
+        UnsafeJsonRewrap<T, T>(testObject, Settings);
+    }
+
+    public static TR UnsafeJsonRewrap<T, TR>(this T source, JsonSerializerSettings settings = null)
+    {
+        var json = settings == null ? 
+            JsonConvert.SerializeObject(source) : 
+            JsonConvert.SerializeObject(source, settings);
+
+        return JsonConvert.DeserializeObject<TR>(json);
+    }
+}

WalletConnectSharp.Core/Controllers/TypedMessageHandler.cs

@@ -1,6 +1,7 @@
 using Newtonsoft.Json;
 using WalletConnectSharp.Common.Logging;
 using WalletConnectSharp.Common.Model.Errors;
+using WalletConnectSharp.Common.Utils;
 using WalletConnectSharp.Core.Interfaces;
 using WalletConnectSharp.Core.Models.Relay;
 using WalletConnectSharp.Crypto.Models;
@@ -14,6 +15,7 @@ public class TypedMessageHandler : ITypedMessageHandler
     {
         private bool _initialized = false;
         private Dictionary<string, DecodeOptions> _decodeOptionsMap = new Dictionary<string, DecodeOptions>();
+        private HashSet<string> _typeSafeCache = new HashSet<string>();
 
         public EventDelegator Events { get; }
 
@@ -303,6 +305,8 @@ public DecodeOptions DecodeOptionForTopic(string topic)
         /// <returns>The id of the request sent</returns>
         public async Task<long> SendRequest<T, TR>(string topic, T parameters, long? expiry = null, EncodeOptions options = null)
         {
+            EnsureTypeIsSerializerSafe(parameters);
+
             var method = RpcMethodAttribute.MethodForType<T>();
 
             var payload = new JsonRpcRequest<T>(method, parameters);
@@ -339,6 +343,8 @@ public async Task<long> SendRequest<T, TR>(string topic, T parameters, long? exp
         /// <typeparam name="TR">The response type</typeparam>
         public async Task SendResult<T, TR>(long id, string topic, TR result, EncodeOptions options = null)
         {
+            EnsureTypeIsSerializerSafe(result);
+
             var payload = new JsonRpcResponse<TR>(id, null, result);
             var message = await this.Core.Crypto.Encode(topic, payload, options);
             var opts = RpcResponseOptionsFromTypes<T, TR>();
@@ -356,6 +362,9 @@ public async Task SendResult<T, TR>(long id, string topic, TR result, EncodeOpti
         /// <typeparam name="TR">The response type</typeparam>
         public async Task SendError<T, TR>(long id, string topic, Error error, EncodeOptions options = null)
         {
+            // Type Error is always serializer safe
+            // EnsureTypeIsSerializerSafe(error);
+
             var payload = new JsonRpcResponse<TR>(id, error, default);
             var message = await this.Core.Crypto.Encode(topic, payload, options);
             var opts = RpcResponseOptionsFromTypes<T, TR>();
@@ -367,5 +376,18 @@ public void Dispose()
         {
             Events?.Dispose();
         }
+
+        private void EnsureTypeIsSerializerSafe<T>(T testObject)
+        {
+            var typeString = typeof(T).FullName;
+            if (_typeSafeCache.Contains(typeString))
+                return;
+
+            // Throw any serialization exceptions now
+            // before it's too late
+            TypeSafety.EnsureTypeSerializerSafe(testObject);
+
+            _typeSafeCache.Add(typeString);
+        }
     }
 }