From 806afeb64bcfda964f622cd737c5ab52304e711c Mon Sep 17 00:00:00 2001
From: ReubenBond <rebond@microsoft.com>
Date: Fri, 18 Jun 2021 08:13:22 -0700
Subject: [PATCH] Add C# 9 record support to serializer (#7108)

Co-authored-by: Oisin Grehan <oisin.grehan@hiloenergie.com>
---
 .../Generators/SerializerGenerator.cs                  |  2 +-
 .../SerializationTests/RoundTripSerializerTests.cs     |  8 ++++++++
 test/Grains/TestGrainInterfaces/IValueTypeTestGrain.cs | 10 +++++++++-
 test/Grains/TestGrainInterfaces/IsExternalInit.cs      |  5 +++++
 test/Grains/TestGrains/RoundtripSerializationGrain.cs  |  5 ++++-
 5 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 test/Grains/TestGrainInterfaces/IsExternalInit.cs

diff --git a/src/Orleans.CodeGenerator/Generators/SerializerGenerator.cs b/src/Orleans.CodeGenerator/Generators/SerializerGenerator.cs
index d6a2ae3d498..b443dbb3029 100644
--- a/src/Orleans.CodeGenerator/Generators/SerializerGenerator.cs
+++ b/src/Orleans.CodeGenerator/Generators/SerializerGenerator.cs
@@ -794,7 +794,7 @@ public FieldInfoMember(SerializerGenerator generator, SemanticModel model, IName
             /// <summary>
             /// Gets a value indicating whether or not this field represents a property with an accessible, non-obsolete setter. 
             /// </summary>
-            public bool IsSettableProperty => this.Property?.SetMethod != null && this.model.IsAccessible(0, this.Property.SetMethod) && !this.IsObsolete;
+            public bool IsSettableProperty => Property?.SetMethod is { } setMethod && model.IsAccessible(0, setMethod) && !setMethod.IsInitOnly && !IsObsolete;
 
             /// <summary>
             /// Gets syntax representing the type of this field.
diff --git a/test/DefaultCluster.Tests/SerializationTests/RoundTripSerializerTests.cs b/test/DefaultCluster.Tests/SerializationTests/RoundTripSerializerTests.cs
index b771be046d5..fff126af183 100644
--- a/test/DefaultCluster.Tests/SerializationTests/RoundTripSerializerTests.cs
+++ b/test/DefaultCluster.Tests/SerializationTests/RoundTripSerializerTests.cs
@@ -13,6 +13,14 @@ public RoundTripSerializerTests(DefaultClusterFixture fixture) : base(fixture)
         {
         }
 
+        [Fact]
+        public async Task Serialize_TestMethodResultRecord()
+        {
+            var grain = this.GrainFactory.GetGrain<IRoundtripSerializationGrain>(GetRandomGrainId());
+            RetVal retVal = await grain.GetRetValForParamVal(new ParamVal(42));
+            Assert.Equal(42, retVal.Value);
+        }
+
         [Fact]
         public async Task Serialize_TestMethodResultEnum()
         {
diff --git a/test/Grains/TestGrainInterfaces/IValueTypeTestGrain.cs b/test/Grains/TestGrainInterfaces/IValueTypeTestGrain.cs
index f21ebb74cb7..98e7814f08d 100644
--- a/test/Grains/TestGrainInterfaces/IValueTypeTestGrain.cs
+++ b/test/Grains/TestGrainInterfaces/IValueTypeTestGrain.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using Orleans;
@@ -144,8 +144,16 @@ public interface IRoundtripSerializationGrain : IGrainWithIntegerKey
         Task<CampaignEnemyTestType> GetEnemyType();
 
         Task<object> GetClosedGenericValue();
+
+        Task<RetVal> GetRetValForParamVal(ParamVal param);
     }
 
+    [Serializable]
+    public record ParamVal(int Value);
+
+    [Serializable]
+    public record RetVal(int Value);
+
     [Serializable]
     [Immutable]
     public class ImmutableType
diff --git a/test/Grains/TestGrainInterfaces/IsExternalInit.cs b/test/Grains/TestGrainInterfaces/IsExternalInit.cs
new file mode 100644
index 00000000000..f7fc37a017a
--- /dev/null
+++ b/test/Grains/TestGrainInterfaces/IsExternalInit.cs
@@ -0,0 +1,5 @@
+namespace System.Runtime.CompilerServices
+{
+    // required for record serialization support for downlevel
+    internal static class IsExternalInit {}
+}
\ No newline at end of file
diff --git a/test/Grains/TestGrains/RoundtripSerializationGrain.cs b/test/Grains/TestGrains/RoundtripSerializationGrain.cs
index 37f3f2e71ec..3bba2a99191 100644
--- a/test/Grains/TestGrains/RoundtripSerializationGrain.cs
+++ b/test/Grains/TestGrains/RoundtripSerializationGrain.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Threading.Tasks;
@@ -20,5 +20,8 @@ public Task<object> GetClosedGenericValue()
             var result = new List<ImmutableList<HashSet<Tuple<int, string>>>>();
             return Task.FromResult((object)result);
         }
+
+        // test record support
+        public Task<RetVal> GetRetValForParamVal(ParamVal param) => Task.FromResult(new RetVal(param.Value));
     }
 }