Added check to allow non spec compliant consumers to send us null for params. When a null is given we won't error, instead we will just pretend we never got any params at all.

Author: david-driscoll

src/JsonRpc/Reciever.cs

@@ -79,11 +79,18 @@ protected virtual Renor GetRenor(JToken @object)
             }
 
             var hasParams = request.TryGetValue("params", out var @params);
-            if (hasParams && @params?.Type != JTokenType.Array && @params?.Type != JTokenType.Object)
+            if (hasParams && @params?.Type != JTokenType.Array && @params?.Type != JTokenType.Object && @params?.Type != JTokenType.Null)
             {
                 return new InvalidRequest(requestId, "Invalid params");
             }
 
+            // Special case params such that if we get a null value (from a non spec compliant system)
+            // that we don't fall over and throw an error.
+            if (@params?.Type == JTokenType.Null)
+            {
+                @params = null;
+            }
+
             // id == request
             // !id == notification
             if (!hasRequestId)

test/JsonRpc.Tests/Server/SpecifictionRecieverTests.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using FluentAssertions;
@@ -56,6 +56,24 @@ public override IEnumerable<ValueTuple<string, Renor[]>> GetValues()
                         new Request(4, "subtract", JObject.FromObject(new {minuend = 42, subtrahend = 23}))
                     });
 
+                yield return (
+                    @"{""jsonrpc"": ""2.0"", ""method"": ""subtract"", ""id"": 4}",
+                    new Renor[]
+                    {
+                        new Request(4, "subtract", null)
+                    });
+
+                // http://www.jsonrpc.org/specification says:
+                //      If present, parameters for the rpc call MUST be provided as a Structured value.
+                // Some clients may serialize params as null, instead of omitting it
+                // We're going to pretend we never got the null in the first place.
+                yield return (
+                    @"{""jsonrpc"": ""2.0"", ""method"": ""subtract"", ""params"": null, ""id"": 4}",
+                    new Renor[]
+                    {
+                        new Request(4, "subtract", null)
+                    });
+
                 yield return (
                     @"{""jsonrpc"": ""2.0"", ""method"": ""update"", ""params"": [1,2,3,4,5]}",
                     new Renor[]
@@ -70,6 +88,17 @@ public override IEnumerable<ValueTuple<string, Renor[]>> GetValues()
                         new Notification("foobar", null)
                     });
 
+                // http://www.jsonrpc.org/specification says:
+                //      If present, parameters for the rpc call MUST be provided as a Structured value.
+                // Some clients may serialize params as null, instead of omitting it
+                // We're going to pretend we never got the null in the first place.
+                yield return (
+                    @"{""jsonrpc"": ""2.0"", ""method"": ""foobar"", ""params"": null}",
+                    new Renor[]
+                    {
+                        new Notification("foobar", null)
+                    });
+
                 yield return (
                     @"{""jsonrpc"": ""2.0"", ""method"": 1, ""params"": ""bar""}",
                     new Renor[]
@@ -144,4 +173,4 @@ public override IEnumerable<ValueTuple<string, bool>> GetValues()
             }
         }
     }
-}
+}