From d6aff08a465c99d0a49f1797b6f20c7c34e8e911 Mon Sep 17 00:00:00 2001
From: Ilia Brahinets <ilia.brahinets@gmail.com>
Date: Fri, 5 Jul 2024 07:46:55 +0300
Subject: [PATCH] [Instrumentation.GrpcCore] Nullable support (#1936)

---
 .../.publicApi/PublicAPI.Shipped.txt          |  1 +
 .../.publicApi/PublicAPI.Unshipped.txt        | 28 ++++++-------
 .../AsyncStreamReaderProxy.cs                 |  8 ++--
 .../CHANGELOG.md                              |  2 +
 .../ClientStreamWriterProxy.cs                |  8 ++--
 .../ClientTracingInterceptor.cs               | 36 ++++++++++------
 .../ClientTracingInterceptorOptions.cs        |  2 +-
 .../GrpcCoreInstrumentation.cs                |  2 +-
 ...nTelemetry.Instrumentation.GrpcCore.csproj |  3 +-
 .../RpcScope.cs                               | 41 +++++++++++--------
 .../ServerStreamWriterProxy.cs                |  4 +-
 .../ServerTracingInterceptorOptions.cs        |  2 +-
 .../FoobarService.cs                          | 14 +++----
 .../GrpcCoreClientInterceptorTests.cs         | 37 +++++++++--------
 .../GrpcCoreServerInterceptorTests.cs         |  7 +++-
 .../InterceptorActivityListener.cs            |  2 +-
 ...etry.Instrumentation.GrpcCore.Tests.csproj |  3 +-
 .../TestActivityTags.cs                       |  4 +-
 18 files changed, 116 insertions(+), 88 deletions(-)

diff --git a/src/OpenTelemetry.Instrumentation.GrpcCore/.publicApi/PublicAPI.Shipped.txt b/src/OpenTelemetry.Instrumentation.GrpcCore/.publicApi/PublicAPI.Shipped.txt
index e69de29bb2..7dc5c58110 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcCore/.publicApi/PublicAPI.Shipped.txt
+++ b/src/OpenTelemetry.Instrumentation.GrpcCore/.publicApi/PublicAPI.Shipped.txt
@@ -0,0 +1 @@
+#nullable enable
diff --git a/src/OpenTelemetry.Instrumentation.GrpcCore/.publicApi/PublicAPI.Unshipped.txt b/src/OpenTelemetry.Instrumentation.GrpcCore/.publicApi/PublicAPI.Unshipped.txt
index 0fb3d72fd9..5415a53f00 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcCore/.publicApi/PublicAPI.Unshipped.txt
+++ b/src/OpenTelemetry.Instrumentation.GrpcCore/.publicApi/PublicAPI.Unshipped.txt
@@ -1,29 +1,29 @@
 OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptor
-OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptor.ClientTracingInterceptor(OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptorOptions options) -> void
+OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptor.ClientTracingInterceptor(OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptorOptions! options) -> void
 OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptorOptions
 OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptorOptions.ClientTracingInterceptorOptions() -> void
-OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptorOptions.Propagator.get -> OpenTelemetry.Context.Propagation.TextMapPropagator
+OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptorOptions.Propagator.get -> OpenTelemetry.Context.Propagation.TextMapPropagator!
 OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptorOptions.RecordException.get -> bool
 OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptorOptions.RecordException.set -> void
 OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptorOptions.RecordMessageEvents.get -> bool
 OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptorOptions.RecordMessageEvents.set -> void
 OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptor
-OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptor.ServerTracingInterceptor(OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptorOptions options) -> void
+OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptor.ServerTracingInterceptor(OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptorOptions! options) -> void
 OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptorOptions
-OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptorOptions.Propagator.get -> OpenTelemetry.Context.Propagation.TextMapPropagator
+OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptorOptions.Propagator.get -> OpenTelemetry.Context.Propagation.TextMapPropagator!
 OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptorOptions.RecordException.get -> bool
 OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptorOptions.RecordException.set -> void
 OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptorOptions.RecordMessageEvents.get -> bool
 OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptorOptions.RecordMessageEvents.set -> void
 OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptorOptions.ServerTracingInterceptorOptions() -> void
 OpenTelemetry.Trace.TracerProviderBuilderExtensions
-override OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptor.AsyncClientStreamingCall<TRequest, TResponse>(Grpc.Core.Interceptors.ClientInterceptorContext<TRequest, TResponse> context, Grpc.Core.Interceptors.Interceptor.AsyncClientStreamingCallContinuation<TRequest, TResponse> continuation) -> Grpc.Core.AsyncClientStreamingCall<TRequest, TResponse>
-override OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptor.AsyncDuplexStreamingCall<TRequest, TResponse>(Grpc.Core.Interceptors.ClientInterceptorContext<TRequest, TResponse> context, Grpc.Core.Interceptors.Interceptor.AsyncDuplexStreamingCallContinuation<TRequest, TResponse> continuation) -> Grpc.Core.AsyncDuplexStreamingCall<TRequest, TResponse>
-override OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptor.AsyncServerStreamingCall<TRequest, TResponse>(TRequest request, Grpc.Core.Interceptors.ClientInterceptorContext<TRequest, TResponse> context, Grpc.Core.Interceptors.Interceptor.AsyncServerStreamingCallContinuation<TRequest, TResponse> continuation) -> Grpc.Core.AsyncServerStreamingCall<TResponse>
-override OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptor.AsyncUnaryCall<TRequest, TResponse>(TRequest request, Grpc.Core.Interceptors.ClientInterceptorContext<TRequest, TResponse> context, Grpc.Core.Interceptors.Interceptor.AsyncUnaryCallContinuation<TRequest, TResponse> continuation) -> Grpc.Core.AsyncUnaryCall<TResponse>
-override OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptor.BlockingUnaryCall<TRequest, TResponse>(TRequest request, Grpc.Core.Interceptors.ClientInterceptorContext<TRequest, TResponse> context, Grpc.Core.Interceptors.Interceptor.BlockingUnaryCallContinuation<TRequest, TResponse> continuation) -> TResponse
-override OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptor.ClientStreamingServerHandler<TRequest, TResponse>(Grpc.Core.IAsyncStreamReader<TRequest> requestStream, Grpc.Core.ServerCallContext context, Grpc.Core.ClientStreamingServerMethod<TRequest, TResponse> continuation) -> System.Threading.Tasks.Task<TResponse>
-override OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptor.DuplexStreamingServerHandler<TRequest, TResponse>(Grpc.Core.IAsyncStreamReader<TRequest> requestStream, Grpc.Core.IServerStreamWriter<TResponse> responseStream, Grpc.Core.ServerCallContext context, Grpc.Core.DuplexStreamingServerMethod<TRequest, TResponse> continuation) -> System.Threading.Tasks.Task
-override OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptor.ServerStreamingServerHandler<TRequest, TResponse>(TRequest request, Grpc.Core.IServerStreamWriter<TResponse> responseStream, Grpc.Core.ServerCallContext context, Grpc.Core.ServerStreamingServerMethod<TRequest, TResponse> continuation) -> System.Threading.Tasks.Task
-override OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptor.UnaryServerHandler<TRequest, TResponse>(TRequest request, Grpc.Core.ServerCallContext context, Grpc.Core.UnaryServerMethod<TRequest, TResponse> continuation) -> System.Threading.Tasks.Task<TResponse>
-static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddGrpcCoreInstrumentation(this OpenTelemetry.Trace.TracerProviderBuilder builder) -> OpenTelemetry.Trace.TracerProviderBuilder
\ No newline at end of file
+override OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptor.AsyncClientStreamingCall<TRequest, TResponse>(Grpc.Core.Interceptors.ClientInterceptorContext<TRequest!, TResponse!> context, Grpc.Core.Interceptors.Interceptor.AsyncClientStreamingCallContinuation<TRequest!, TResponse!>! continuation) -> Grpc.Core.AsyncClientStreamingCall<TRequest!, TResponse!>!
+override OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptor.AsyncDuplexStreamingCall<TRequest, TResponse>(Grpc.Core.Interceptors.ClientInterceptorContext<TRequest!, TResponse!> context, Grpc.Core.Interceptors.Interceptor.AsyncDuplexStreamingCallContinuation<TRequest!, TResponse!>! continuation) -> Grpc.Core.AsyncDuplexStreamingCall<TRequest!, TResponse!>!
+override OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptor.AsyncServerStreamingCall<TRequest, TResponse>(TRequest! request, Grpc.Core.Interceptors.ClientInterceptorContext<TRequest!, TResponse!> context, Grpc.Core.Interceptors.Interceptor.AsyncServerStreamingCallContinuation<TRequest!, TResponse!>! continuation) -> Grpc.Core.AsyncServerStreamingCall<TResponse!>!
+override OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptor.AsyncUnaryCall<TRequest, TResponse>(TRequest! request, Grpc.Core.Interceptors.ClientInterceptorContext<TRequest!, TResponse!> context, Grpc.Core.Interceptors.Interceptor.AsyncUnaryCallContinuation<TRequest!, TResponse!>! continuation) -> Grpc.Core.AsyncUnaryCall<TResponse!>!
+override OpenTelemetry.Instrumentation.GrpcCore.ClientTracingInterceptor.BlockingUnaryCall<TRequest, TResponse>(TRequest! request, Grpc.Core.Interceptors.ClientInterceptorContext<TRequest!, TResponse!> context, Grpc.Core.Interceptors.Interceptor.BlockingUnaryCallContinuation<TRequest!, TResponse!>! continuation) -> TResponse!
+override OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptor.ClientStreamingServerHandler<TRequest, TResponse>(Grpc.Core.IAsyncStreamReader<TRequest!>! requestStream, Grpc.Core.ServerCallContext! context, Grpc.Core.ClientStreamingServerMethod<TRequest!, TResponse!>! continuation) -> System.Threading.Tasks.Task<TResponse!>!
+override OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptor.DuplexStreamingServerHandler<TRequest, TResponse>(Grpc.Core.IAsyncStreamReader<TRequest!>! requestStream, Grpc.Core.IServerStreamWriter<TResponse!>! responseStream, Grpc.Core.ServerCallContext! context, Grpc.Core.DuplexStreamingServerMethod<TRequest!, TResponse!>! continuation) -> System.Threading.Tasks.Task!
+override OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptor.ServerStreamingServerHandler<TRequest, TResponse>(TRequest! request, Grpc.Core.IServerStreamWriter<TResponse!>! responseStream, Grpc.Core.ServerCallContext! context, Grpc.Core.ServerStreamingServerMethod<TRequest!, TResponse!>! continuation) -> System.Threading.Tasks.Task!
+override OpenTelemetry.Instrumentation.GrpcCore.ServerTracingInterceptor.UnaryServerHandler<TRequest, TResponse>(TRequest! request, Grpc.Core.ServerCallContext! context, Grpc.Core.UnaryServerMethod<TRequest!, TResponse!>! continuation) -> System.Threading.Tasks.Task<TResponse!>!
+static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddGrpcCoreInstrumentation(this OpenTelemetry.Trace.TracerProviderBuilder! builder) -> OpenTelemetry.Trace.TracerProviderBuilder!
diff --git a/src/OpenTelemetry.Instrumentation.GrpcCore/AsyncStreamReaderProxy.cs b/src/OpenTelemetry.Instrumentation.GrpcCore/AsyncStreamReaderProxy.cs
index a0d1b03303..0885767c8a 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcCore/AsyncStreamReaderProxy.cs
+++ b/src/OpenTelemetry.Instrumentation.GrpcCore/AsyncStreamReaderProxy.cs
@@ -24,17 +24,17 @@ internal class AsyncStreamReaderProxy<T> : IAsyncStreamReader<T>
     /// <summary>
     /// The on message action.
     /// </summary>
-    private readonly Action<T> onMessage;
+    private readonly Action<T>? onMessage;
 
     /// <summary>
     /// The on stream end action.
     /// </summary>
-    private readonly Action onStreamEnd;
+    private readonly Action? onStreamEnd;
 
     /// <summary>
     /// The on exception action.
     /// </summary>
-    private readonly Action<Exception> onException;
+    private readonly Action<Exception>? onException;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="AsyncStreamReaderProxy{T}"/> class.
@@ -43,7 +43,7 @@ internal class AsyncStreamReaderProxy<T> : IAsyncStreamReader<T>
     /// <param name="onMessage">The on message action, if any.</param>
     /// <param name="onStreamEnd">The on stream end action, if any.</param>
     /// <param name="onException">The on exception action, if any.</param>
-    public AsyncStreamReaderProxy(IAsyncStreamReader<T> reader, Action<T> onMessage = null, Action onStreamEnd = null, Action<Exception> onException = null)
+    public AsyncStreamReaderProxy(IAsyncStreamReader<T> reader, Action<T>? onMessage = null, Action? onStreamEnd = null, Action<Exception>? onException = null)
     {
         this.reader = reader;
         this.onMessage = onMessage;
diff --git a/src/OpenTelemetry.Instrumentation.GrpcCore/CHANGELOG.md b/src/OpenTelemetry.Instrumentation.GrpcCore/CHANGELOG.md
index 2c50800621..276fedf468 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcCore/CHANGELOG.md
+++ b/src/OpenTelemetry.Instrumentation.GrpcCore/CHANGELOG.md
@@ -4,6 +4,8 @@
 
 * Updated OpenTelemetry core component version(s) to `1.9.0`.
   ([#1888](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/1888))
+* Updated minimal supported version of `Grpc.Core.Api` to `2.43.0`.
+  ([#1936](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/1936))
 
 ## 1.0.0-beta.6
 
diff --git a/src/OpenTelemetry.Instrumentation.GrpcCore/ClientStreamWriterProxy.cs b/src/OpenTelemetry.Instrumentation.GrpcCore/ClientStreamWriterProxy.cs
index 254b4ba709..eafbd3bb32 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcCore/ClientStreamWriterProxy.cs
+++ b/src/OpenTelemetry.Instrumentation.GrpcCore/ClientStreamWriterProxy.cs
@@ -24,17 +24,17 @@ internal class ClientStreamWriterProxy<T> : IClientStreamWriter<T>
     /// <summary>
     /// The on write action.
     /// </summary>
-    private readonly Action<T> onWrite;
+    private readonly Action<T>? onWrite;
 
     /// <summary>
     /// The on complete action.
     /// </summary>
-    private readonly Action onComplete;
+    private readonly Action? onComplete;
 
     /// <summary>
     /// The on exception action.
     /// </summary>
-    private readonly Action<Exception> onException;
+    private readonly Action<Exception>? onException;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="ClientStreamWriterProxy{T}"/> class.
@@ -43,7 +43,7 @@ internal class ClientStreamWriterProxy<T> : IClientStreamWriter<T>
     /// <param name="onWrite">The on write action if any.</param>
     /// <param name="onComplete">The on complete action, if any.</param>
     /// <param name="onException">The on exception action, if any.</param>
-    public ClientStreamWriterProxy(IClientStreamWriter<T> writer, Action<T> onWrite = null, Action onComplete = null, Action<Exception> onException = null)
+    public ClientStreamWriterProxy(IClientStreamWriter<T> writer, Action<T>? onWrite = null, Action? onComplete = null, Action<Exception>? onException = null)
     {
         this.writer = writer;
         this.onWrite = onWrite;
diff --git a/src/OpenTelemetry.Instrumentation.GrpcCore/ClientTracingInterceptor.cs b/src/OpenTelemetry.Instrumentation.GrpcCore/ClientTracingInterceptor.cs
index 7f5d7d7da9..ce87f3a3d8 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcCore/ClientTracingInterceptor.cs
+++ b/src/OpenTelemetry.Instrumentation.GrpcCore/ClientTracingInterceptor.cs
@@ -40,7 +40,7 @@ public override TResponse BlockingUnaryCall<TRequest, TResponse>(
         Guard.ThrowIfNull(context);
         Guard.ThrowIfNull(continuation);
 
-        ClientRpcScope<TRequest, TResponse> rpcScope = null;
+        ClientRpcScope<TRequest, TResponse>? rpcScope = null;
 
         try
         {
@@ -72,7 +72,7 @@ public override AsyncUnaryCall<TResponse> AsyncUnaryCall<TRequest, TResponse>(
         Guard.ThrowIfNull(context);
         Guard.ThrowIfNull(continuation);
 
-        ClientRpcScope<TRequest, TResponse> rpcScope = null;
+        ClientRpcScope<TRequest, TResponse>? rpcScope = null;
 
         try
         {
@@ -93,8 +93,14 @@ public override AsyncUnaryCall<TResponse> AsyncUnaryCall<TRequest, TResponse>(
                     }
                     catch (AggregateException ex)
                     {
-                        rpcScope.CompleteWithException(ex.InnerException);
-                        throw ex.InnerException;
+                        if (ex.InnerException != null)
+                        {
+                            rpcScope.CompleteWithException(ex.InnerException);
+                            throw ex.InnerException;
+                        }
+
+                        rpcScope.CompleteWithException(ex);
+                        throw;
                     }
                 },
                 TaskScheduler.Current);
@@ -125,7 +131,7 @@ public override AsyncClientStreamingCall<TRequest, TResponse> AsyncClientStreami
         Guard.ThrowIfNull(context);
         Guard.ThrowIfNull(continuation);
 
-        ClientRpcScope<TRequest, TResponse> rpcScope = null;
+        ClientRpcScope<TRequest, TResponse>? rpcScope = null;
 
         try
         {
@@ -150,8 +156,14 @@ public override AsyncClientStreamingCall<TRequest, TResponse> AsyncClientStreami
                     }
                     catch (AggregateException ex)
                     {
-                        rpcScope.CompleteWithException(ex.InnerException);
-                        throw ex.InnerException;
+                        if (ex.InnerException != null)
+                        {
+                            rpcScope.CompleteWithException(ex.InnerException);
+                            throw ex.InnerException;
+                        }
+
+                        rpcScope.CompleteWithException(ex);
+                        throw;
                     }
                 },
                 TaskScheduler.Current);
@@ -184,7 +196,7 @@ public override AsyncServerStreamingCall<TResponse> AsyncServerStreamingCall<TRe
         Guard.ThrowIfNull(context);
         Guard.ThrowIfNull(continuation);
 
-        ClientRpcScope<TRequest, TResponse> rpcScope = null;
+        ClientRpcScope<TRequest, TResponse>? rpcScope = null;
 
         try
         {
@@ -226,7 +238,7 @@ public override AsyncDuplexStreamingCall<TRequest, TResponse> AsyncDuplexStreami
         Guard.ThrowIfNull(context);
         Guard.ThrowIfNull(continuation);
 
-        ClientRpcScope<TRequest, TResponse> rpcScope = null;
+        ClientRpcScope<TRequest, TResponse>? rpcScope = null;
 
         try
         {
@@ -277,7 +289,7 @@ private sealed class ClientRpcScope<TRequest, TResponse> : RpcScope<TRequest, TR
         /// <summary>
         /// The metadata setter action.
         /// </summary>
-        private static readonly Action<Metadata, string, string> MetadataSetter = (metadata, key, value) => { metadata.Add(new Metadata.Entry(key, value)); };
+        private static readonly Action<Metadata?, string, string> MetadataSetter = (metadata, key, value) => { metadata?.Add(new Metadata.Entry(key, value)); };
 
         /// <summary>
         /// The context.
@@ -287,7 +299,7 @@ private sealed class ClientRpcScope<TRequest, TResponse> : RpcScope<TRequest, TR
         /// <summary>
         /// The parent activity.
         /// </summary>
-        private readonly Activity parentActivity;
+        private readonly Activity? parentActivity;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="ClientRpcScope{TRequest, TResponse}" /> class.
@@ -343,7 +355,7 @@ public ClientRpcScope(ClientInterceptorContext<TRequest, TResponse> context, Cli
 
             this.SetActivity(rpcActivity);
             options.Propagator.Inject(new PropagationContext(rpcActivity.Context, Baggage.Current), callOptions.Headers, MetadataSetter);
-            this.context = new ClientInterceptorContext<TRequest, TResponse>(context.Method, context.Host, callOptions);
+            this.context = new ClientInterceptorContext<TRequest, TResponse>(context.Method!, context.Host, callOptions);
         }
 
         /// <summary>
diff --git a/src/OpenTelemetry.Instrumentation.GrpcCore/ClientTracingInterceptorOptions.cs b/src/OpenTelemetry.Instrumentation.GrpcCore/ClientTracingInterceptorOptions.cs
index 02d214fea1..4e720ae237 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcCore/ClientTracingInterceptorOptions.cs
+++ b/src/OpenTelemetry.Instrumentation.GrpcCore/ClientTracingInterceptorOptions.cs
@@ -28,5 +28,5 @@ public class ClientTracingInterceptorOptions
     /// <summary>
     /// Gets or sets additional activity tags used during unit testing.
     /// </summary>
-    internal IReadOnlyDictionary<string, object> AdditionalTags { get; set; }
+    internal IReadOnlyDictionary<string, object?>? AdditionalTags { get; set; }
 }
diff --git a/src/OpenTelemetry.Instrumentation.GrpcCore/GrpcCoreInstrumentation.cs b/src/OpenTelemetry.Instrumentation.GrpcCore/GrpcCoreInstrumentation.cs
index a3a627133a..b7285ca7d3 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcCore/GrpcCoreInstrumentation.cs
+++ b/src/OpenTelemetry.Instrumentation.GrpcCore/GrpcCoreInstrumentation.cs
@@ -25,7 +25,7 @@ internal static class GrpcCoreInstrumentation
     /// <summary>
     /// The activity source name.
     /// </summary>
-    internal static readonly string ActivitySourceName = AssemblyName.Name;
+    internal static readonly string ActivitySourceName = AssemblyName.Name!;
 
     /// <summary>
     /// The activity source.
diff --git a/src/OpenTelemetry.Instrumentation.GrpcCore/OpenTelemetry.Instrumentation.GrpcCore.csproj b/src/OpenTelemetry.Instrumentation.GrpcCore/OpenTelemetry.Instrumentation.GrpcCore.csproj
index 099152bc14..c0bd481471 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcCore/OpenTelemetry.Instrumentation.GrpcCore.csproj
+++ b/src/OpenTelemetry.Instrumentation.GrpcCore/OpenTelemetry.Instrumentation.GrpcCore.csproj
@@ -4,7 +4,6 @@
     <Description>.NET gRPC Core based client and server interceptors for OpenTelemetry.</Description>
     <PackageTags>$(PackageTags);gRPC Core;interceptors</PackageTags>
     <MinVerTagPrefix>Instrumentation.GrpcCore-</MinVerTagPrefix>
-    <Nullable>disable</Nullable>
   </PropertyGroup>
 
   <!--Do not run Package Baseline Validation as this package has never released a stable version.
@@ -15,7 +14,7 @@
 
   <ItemGroup>
     <PackageReference Include="Google.Protobuf" Version="[3.15.0,4.0)" />
-    <PackageReference Include="Grpc.Core.Api" Version="[2.23.0,3.0)" />
+    <PackageReference Include="Grpc.Core.Api" Version="[2.43.0,3.0)" />
     <PackageReference Include="OpenTelemetry.Api" Version="$(OpenTelemetryCoreLatestVersion)" />
   </ItemGroup>
 
diff --git a/src/OpenTelemetry.Instrumentation.GrpcCore/RpcScope.cs b/src/OpenTelemetry.Instrumentation.GrpcCore/RpcScope.cs
index 5ca663ab81..24571bacb6 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcCore/RpcScope.cs
+++ b/src/OpenTelemetry.Instrumentation.GrpcCore/RpcScope.cs
@@ -4,6 +4,7 @@
 using System.Diagnostics;
 using Google.Protobuf;
 using Grpc.Core;
+using OpenTelemetry.Internal;
 using OpenTelemetry.Trace;
 using StatusCode = Grpc.Core.StatusCode;
 
@@ -31,7 +32,7 @@ internal abstract class RpcScope<TRequest, TResponse> : IDisposable
     /// <summary>
     /// The RPC activity.
     /// </summary>
-    private Activity activity;
+    private Activity? activity;
 
     /// <summary>
     /// The complete flag.
@@ -54,7 +55,7 @@ internal abstract class RpcScope<TRequest, TResponse> : IDisposable
     /// <param name="fullServiceName">Full name of the service.</param>
     /// <param name="recordMessageEvents">if set to <c>true</c> [record message events].</param>
     /// <param name="recordException">If set to <c>true</c> [record exception].</param>
-    protected RpcScope(string fullServiceName, bool recordMessageEvents, bool recordException)
+    protected RpcScope(string? fullServiceName, bool recordMessageEvents, bool recordException)
     {
         this.FullServiceName = fullServiceName?.TrimStart('/') ?? "unknownservice/unknownmethod";
         this.recordMessageEvents = recordMessageEvents;
@@ -72,6 +73,8 @@ protected RpcScope(string fullServiceName, bool recordMessageEvents, bool record
     /// <param name="request">The request.</param>
     public void RecordRequest(TRequest request)
     {
+        Guard.ThrowIfNull(request);
+
         this.requestMessageCounter++;
 
         if (this.activity == null || !this.activity.IsAllDataRequested || !this.recordMessageEvents)
@@ -79,7 +82,7 @@ public void RecordRequest(TRequest request)
             return;
         }
 
-        this.AddMessageEvent(typeof(TRequest).Name, request as IMessage, request: true);
+        this.AddMessageEvent(typeof(TRequest).Name, (request as IMessage)!, request: true);
     }
 
     /// <summary>
@@ -88,6 +91,8 @@ public void RecordRequest(TRequest request)
     /// <param name="response">The response.</param>
     public void RecordResponse(TResponse response)
     {
+        Guard.ThrowIfNull(response);
+
         this.responseMessageCounter++;
 
         if (this.activity == null || !this.activity.IsAllDataRequested || !this.recordMessageEvents)
@@ -95,7 +100,7 @@ public void RecordResponse(TResponse response)
             return;
         }
 
-        this.AddMessageEvent(typeof(TResponse).Name, response as IMessage, request: false);
+        this.AddMessageEvent(typeof(TResponse).Name, (response as IMessage)!, request: false);
     }
 
     /// <summary>
@@ -118,6 +123,8 @@ public void Complete()
     /// <param name="exception">The exception.</param>
     public void CompleteWithException(Exception exception)
     {
+        Guard.ThrowIfNull(exception);
+
         if (this.activity == null)
         {
             return;
@@ -142,7 +149,7 @@ public void Dispose()
     /// Sets the activity for this RPC scope. Should only be called once.
     /// </summary>
     /// <param name="activity">The activity.</param>
-    protected void SetActivity(Activity activity)
+    protected void SetActivity(Activity? activity)
     {
         this.activity = activity;
 
@@ -180,7 +187,7 @@ private void StopActivity(int statusCode, bool markAsCompleted = true)
             return;
         }
 
-        this.activity.SetTag(SemanticConventions.AttributeRpcGrpcStatusCode, statusCode);
+        this.activity!.SetTag(SemanticConventions.AttributeRpcGrpcStatusCode, statusCode);
         this.activity.Stop();
     }
 
@@ -206,10 +213,10 @@ private void StopActivity(Exception exception)
 
         if (!string.IsNullOrEmpty(description))
         {
-            this.activity.SetStatus(ActivityStatusCode.Error, description);
+            this.activity!.SetStatus(ActivityStatusCode.Error, description);
         }
 
-        if (this.activity.IsAllDataRequested && this.recordException)
+        if (this.activity!.IsAllDataRequested && this.recordException)
         {
             this.activity.RecordException(exception);
         }
@@ -236,17 +243,17 @@ private void AddMessageEvent(string eventName, IMessage message, bool request)
     {
         var messageSize = message.CalculateSize();
 
-        var attributes = new ActivityTagsCollection(new KeyValuePair<string, object>[5]
-        {
-            new KeyValuePair<string, object>("name", "message"),
-            new KeyValuePair<string, object>(SemanticConventions.AttributeMessageType, request ? "SENT" : "RECEIVED"),
-            new KeyValuePair<string, object>(SemanticConventions.AttributeMessageId, request ? this.requestMessageCounter : this.responseMessageCounter),
+        var attributes = new ActivityTagsCollection(
+        [
+            new("name", "message"),
+            new(SemanticConventions.AttributeMessageType, request ? "SENT" : "RECEIVED"),
+            new(SemanticConventions.AttributeMessageId, request ? this.requestMessageCounter : this.responseMessageCounter),
 
             // TODO how to get the real compressed or uncompressed sizes
-            new KeyValuePair<string, object>(SemanticConventions.AttributeMessageCompressedSize, messageSize),
-            new KeyValuePair<string, object>(SemanticConventions.AttributeMessageUncompressedSize, messageSize),
-        });
+            new(SemanticConventions.AttributeMessageCompressedSize, messageSize),
+            new(SemanticConventions.AttributeMessageUncompressedSize, messageSize),
+        ]);
 
-        this.activity.AddEvent(new ActivityEvent(eventName, default, attributes));
+        this.activity!.AddEvent(new ActivityEvent(eventName, default, attributes));
     }
 }
diff --git a/src/OpenTelemetry.Instrumentation.GrpcCore/ServerStreamWriterProxy.cs b/src/OpenTelemetry.Instrumentation.GrpcCore/ServerStreamWriterProxy.cs
index f07e17c0f6..2fdbf22b13 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcCore/ServerStreamWriterProxy.cs
+++ b/src/OpenTelemetry.Instrumentation.GrpcCore/ServerStreamWriterProxy.cs
@@ -24,14 +24,14 @@ internal class ServerStreamWriterProxy<T> : IServerStreamWriter<T>
     /// <summary>
     /// The on write action.
     /// </summary>
-    private readonly Action<T> onWrite;
+    private readonly Action<T>? onWrite;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="ServerStreamWriterProxy{T}"/> class.
     /// </summary>
     /// <param name="writer">The writer.</param>
     /// <param name="onWrite">The on write action, if any.</param>
-    public ServerStreamWriterProxy(IServerStreamWriter<T> writer, Action<T> onWrite = null)
+    public ServerStreamWriterProxy(IServerStreamWriter<T> writer, Action<T>? onWrite = null)
     {
         this.writer = writer;
         this.onWrite = onWrite;
diff --git a/src/OpenTelemetry.Instrumentation.GrpcCore/ServerTracingInterceptorOptions.cs b/src/OpenTelemetry.Instrumentation.GrpcCore/ServerTracingInterceptorOptions.cs
index 9b0b6ca360..b759cb8fff 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcCore/ServerTracingInterceptorOptions.cs
+++ b/src/OpenTelemetry.Instrumentation.GrpcCore/ServerTracingInterceptorOptions.cs
@@ -28,5 +28,5 @@ public class ServerTracingInterceptorOptions
     /// <summary>
     /// Gets or sets additional activity tags used during unit testing.
     /// </summary>
-    internal IReadOnlyDictionary<string, object> AdditionalTags { get; set; }
+    internal IReadOnlyDictionary<string, object?>? AdditionalTags { get; set; }
 }
diff --git a/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/FoobarService.cs b/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/FoobarService.cs
index 871299dd68..1942f5f88f 100644
--- a/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/FoobarService.cs
+++ b/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/FoobarService.cs
@@ -58,7 +58,7 @@ internal class FoobarService : Foobar.FoobarBase
     /// </summary>
     /// <param name="serverInterceptor">The server interceptor.</param>
     /// <returns>A tuple.</returns>
-    public static DisposableServer Start(Interceptor serverInterceptor = null)
+    public static DisposableServer Start(Interceptor? serverInterceptor = null)
     {
         // Disable SO_REUSEPORT to prevent https://github.com/grpc/grpc/issues/10755
         var serviceDefinition = Foobar.BindService(new FoobarService());
@@ -90,8 +90,8 @@ public static DisposableServer Start(Interceptor serverInterceptor = null)
     /// </returns>
     public static Foobar.FoobarClient ConstructRpcClient(
         string target,
-        ClientTracingInterceptor clientTracingInterceptor = null,
-        IEnumerable<Metadata.Entry> additionalMetadata = null)
+        ClientTracingInterceptor? clientTracingInterceptor = null,
+        IEnumerable<Metadata.Entry>? additionalMetadata = null)
     {
         var channel = new Channel(target, ChannelCredentials.Insecure);
         var callInvoker = channel.CreateCallInvoker();
@@ -125,7 +125,7 @@ public static Foobar.FoobarClient ConstructRpcClient(
     /// <param name="client">The client.</param>
     /// <param name="additionalMetadata">The additional metadata.</param>
     /// <returns>A Task.</returns>
-    public static async Task MakeUnaryAsyncRequest(Foobar.FoobarClient client, Metadata additionalMetadata)
+    public static async Task MakeUnaryAsyncRequest(Foobar.FoobarClient client, Metadata? additionalMetadata)
     {
         using var call = client.UnaryAsync(DefaultRequestMessage, headers: additionalMetadata);
         _ = await call.ResponseAsync.ConfigureAwait(false);
@@ -137,7 +137,7 @@ public static async Task MakeUnaryAsyncRequest(Foobar.FoobarClient client, Metad
     /// <param name="client">The client.</param>
     /// <param name="additionalMetadata">The additional metadata.</param>
     /// <returns>A Task.</returns>
-    public static async Task MakeClientStreamingRequest(Foobar.FoobarClient client, Metadata additionalMetadata)
+    public static async Task MakeClientStreamingRequest(Foobar.FoobarClient client, Metadata? additionalMetadata)
     {
         using var call = client.ClientStreaming(headers: additionalMetadata);
         await call.RequestStream.WriteAsync(DefaultRequestMessage).ConfigureAwait(false);
@@ -151,7 +151,7 @@ public static async Task MakeClientStreamingRequest(Foobar.FoobarClient client,
     /// <param name="client">The client.</param>
     /// <param name="additionalMetadata">The additional metadata.</param>
     /// <returns>A Task.</returns>
-    public static async Task MakeServerStreamingRequest(Foobar.FoobarClient client, Metadata additionalMetadata)
+    public static async Task MakeServerStreamingRequest(Foobar.FoobarClient client, Metadata? additionalMetadata)
     {
         using var call = client.ServerStreaming(DefaultRequestMessage, headers: additionalMetadata);
         while (await call.ResponseStream.MoveNext().ConfigureAwait(false))
@@ -165,7 +165,7 @@ public static async Task MakeServerStreamingRequest(Foobar.FoobarClient client,
     /// <param name="client">The client.</param>
     /// <param name="additionalMetadata">The additional metadata.</param>
     /// <returns>A Task.</returns>
-    public static async Task MakeDuplexStreamingRequest(Foobar.FoobarClient client, Metadata additionalMetadata)
+    public static async Task MakeDuplexStreamingRequest(Foobar.FoobarClient client, Metadata? additionalMetadata)
     {
         using var call = client.DuplexStreaming(headers: additionalMetadata);
         await call.RequestStream.WriteAsync(DefaultRequestMessage).ConfigureAwait(false);
diff --git a/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/GrpcCoreClientInterceptorTests.cs b/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/GrpcCoreClientInterceptorTests.cs
index f0bf45e463..150f20a358 100644
--- a/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/GrpcCoreClientInterceptorTests.cs
+++ b/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/GrpcCoreClientInterceptorTests.cs
@@ -227,7 +227,7 @@ public async Task DownstreamInterceptorActivityAccess()
             metadata =>
             {
                 // This Func is called as part of an internal MetadataInjector interceptor created by gRPC Core.
-                Assert.True(Activity.Current.Source == GrpcCoreInstrumentation.ActivitySource);
+                Assert.True(Activity.Current?.Source == GrpcCoreInstrumentation.ActivitySource);
                 Assert.Equal(parentActivity.Id, Activity.Current.ParentId);
 
                 // Set a tag on the Activity and make sure we can see it afterwards
@@ -243,7 +243,8 @@ public async Task DownstreamInterceptorActivityAccess()
         static void ValidateNewTagOnActivity(InterceptorActivityListener listener)
         {
             var createdActivity = listener.Activity;
-            Assert.Contains(createdActivity.TagObjects, t => t.Key == "foo" && (string)t.Value == "bar");
+            Assert.NotNull(createdActivity);
+            Assert.Contains(createdActivity.TagObjects, t => t.Key == "foo" && (string?)t.Value == "bar");
         }
 
         // Check the blocking async call
@@ -307,7 +308,7 @@ static void ValidateNewTagOnActivity(InterceptorActivityListener listener)
     /// <param name="recordedMessages">if set to <c>true</c> [recorded messages].</param>
     /// <param name="recordedExceptions">if set to <c>true</c> [recorded exceptions].</param>
     internal static void ValidateCommonActivityTags(
-        Activity activity,
+        Activity? activity,
         StatusCode expectedStatusCode = StatusCode.OK,
         bool recordedMessages = false,
         bool recordedExceptions = false)
@@ -320,10 +321,10 @@ internal static void ValidateCommonActivityTags(
 
         // TagObjects contain non string values
         // Tags contains only string values
-        Assert.Contains(activity.TagObjects, t => t.Key == SemanticConventions.AttributeRpcSystem && (string)t.Value == "grpc");
-        Assert.Contains(activity.TagObjects, t => t.Key == SemanticConventions.AttributeRpcService && (string)t.Value == "OpenTelemetry.Instrumentation.GrpcCore.Tests.Foobar");
+        Assert.Contains(activity.TagObjects, t => t.Key == SemanticConventions.AttributeRpcSystem && (string?)t.Value == "grpc");
+        Assert.Contains(activity.TagObjects, t => t.Key == SemanticConventions.AttributeRpcService && (string?)t.Value == "OpenTelemetry.Instrumentation.GrpcCore.Tests.Foobar");
         Assert.Contains(activity.TagObjects, t => t.Key == SemanticConventions.AttributeRpcMethod);
-        Assert.Contains(activity.TagObjects, t => t.Key == SemanticConventions.AttributeRpcGrpcStatusCode && (int)t.Value == (int)expectedStatusCode);
+        Assert.Contains(activity.TagObjects, t => t.Key == SemanticConventions.AttributeRpcGrpcStatusCode && (int?)t.Value == (int)expectedStatusCode);
 
         // Cancelled is not an error.
         if (expectedStatusCode != StatusCode.OK && expectedStatusCode != StatusCode.Cancelled)
@@ -341,20 +342,20 @@ internal static void ValidateCommonActivityTags(
             static void ValidateCommonEventAttributes(ActivityEvent activityEvent)
             {
                 Assert.NotNull(activityEvent.Tags);
-                Assert.Contains(activityEvent.Tags, t => t.Key == "name" && (string)t.Value == "message");
-                Assert.Contains(activityEvent.Tags, t => t.Key == SemanticConventions.AttributeMessageId && (int)t.Value == 1);
+                Assert.Contains(activityEvent.Tags, t => t.Key == "name" && (string?)t.Value == "message");
+                Assert.Contains(activityEvent.Tags, t => t.Key == SemanticConventions.AttributeMessageId && (int?)t.Value == 1);
             }
 
             Assert.NotEqual(default, requestMessage);
             Assert.NotEqual(default, responseMessage);
 
             ValidateCommonEventAttributes(requestMessage);
-            Assert.Contains(requestMessage.Tags, t => t.Key == SemanticConventions.AttributeMessageType && (string)t.Value == "SENT");
-            Assert.Contains(requestMessage.Tags, t => t.Key == SemanticConventions.AttributeMessageCompressedSize && (int)t.Value == FoobarService.DefaultRequestMessageSize);
+            Assert.Contains(requestMessage.Tags, t => t.Key == SemanticConventions.AttributeMessageType && (string?)t.Value == "SENT");
+            Assert.Contains(requestMessage.Tags, t => t.Key == SemanticConventions.AttributeMessageCompressedSize && (int?)t.Value == FoobarService.DefaultRequestMessageSize);
 
             ValidateCommonEventAttributes(responseMessage);
-            Assert.Contains(responseMessage.Tags, t => t.Key == SemanticConventions.AttributeMessageType && (string)t.Value == "RECEIVED");
-            Assert.Contains(requestMessage.Tags, t => t.Key == SemanticConventions.AttributeMessageCompressedSize && (int)t.Value == FoobarService.DefaultResponseMessageSize);
+            Assert.Contains(responseMessage.Tags, t => t.Key == SemanticConventions.AttributeMessageType && (string?)t.Value == "RECEIVED");
+            Assert.Contains(requestMessage.Tags, t => t.Key == SemanticConventions.AttributeMessageCompressedSize && (int?)t.Value == FoobarService.DefaultResponseMessageSize);
         }
 
         if (recordedExceptions)
@@ -364,7 +365,7 @@ static void ValidateCommonEventAttributes(ActivityEvent activityEvent)
 
             var exceptionEvent = activity.Events.First(e => e.Name == SemanticConventions.AttributeExceptionEventName);
             Assert.NotNull(exceptionEvent.Tags);
-            Assert.Contains(exceptionEvent.Tags, t => t.Key == SemanticConventions.AttributeExceptionType && (string)t.Value == typeof(RpcException).FullName);
+            Assert.Contains(exceptionEvent.Tags, t => t.Key == SemanticConventions.AttributeExceptionType && (string?)t.Value == typeof(RpcException).FullName);
             Assert.Contains(exceptionEvent.Tags, t => t.Key == SemanticConventions.AttributeExceptionMessage);
             Assert.Contains(exceptionEvent.Tags, t => t.Key == SemanticConventions.AttributeExceptionStacktrace);
         }
@@ -380,7 +381,7 @@ private static async Task TestHandlerSuccess(Func<Foobar.FoobarClient, Metadata,
     {
         var propagator = new TestTextMapPropagator();
         PropagationContext capturedPropagationContext = default;
-        Metadata capturedCarrier = null;
+        Metadata? capturedCarrier = null;
         var propagatorCalled = 0;
         var originalMetadataCount = additionalMetadata.Count;
 
@@ -431,11 +432,13 @@ private static async Task TestHandlerSuccess(Func<Foobar.FoobarClient, Metadata,
             // There was no parent activity, so these will be default
             Assert.NotEqual(default, capturedPropagationContext.ActivityContext.TraceId);
             Assert.NotEqual(default, capturedPropagationContext.ActivityContext.SpanId);
+            Assert.NotNull(activity);
             Assert.Null(activity.Parent);
             Assert.Equal(activity.TraceId, capturedPropagationContext.ActivityContext.TraceId);
             Assert.Equal(activity.SpanId, capturedPropagationContext.ActivityContext.SpanId);
 
             // Sanity check a valid metadata injection setter.
+            Assert.NotNull(capturedCarrier);
             Assert.NotEmpty(capturedCarrier);
 
             ValidateCommonActivityTags(activity, StatusCode.OK, interceptorOptions.RecordMessageEvents);
@@ -465,6 +468,7 @@ private static async Task TestHandlerSuccess(Func<Foobar.FoobarClient, Metadata,
 
             var activity = activityListener.Activity;
             ValidateCommonActivityTags(activity, StatusCode.OK, interceptorOptions.RecordMessageEvents);
+            Assert.NotNull(activity);
             Assert.Equal(parentActivity.Id, activity.ParentId);
         }
     }
@@ -480,10 +484,10 @@ private static async Task TestHandlerSuccess(Func<Foobar.FoobarClient, Metadata,
     /// A Task.
     /// </returns>
     private static async Task TestHandlerFailure(
-        Func<Foobar.FoobarClient, Metadata, Task> clientRequestFunc,
+        Func<Foobar.FoobarClient, Metadata?, Task> clientRequestFunc,
         StatusCode statusCode = StatusCode.ResourceExhausted,
         bool validateErrorDescription = true,
-        string serverUriString = null)
+        string? serverUriString = null)
     {
         using var server = FoobarService.Start();
         var testTags = new TestActivityTags();
@@ -505,6 +509,7 @@ private static async Task TestHandlerFailure(
 
         if (validateErrorDescription)
         {
+            Assert.NotNull(activity);
             Assert.Contains("fubar", activity.StatusDescription);
         }
     }
diff --git a/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/GrpcCoreServerInterceptorTests.cs b/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/GrpcCoreServerInterceptorTests.cs
index a3aa5af28d..bd892bd77a 100644
--- a/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/GrpcCoreServerInterceptorTests.cs
+++ b/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/GrpcCoreServerInterceptorTests.cs
@@ -98,7 +98,7 @@ public async Task DuplexStreamingServerHandlerFail()
     /// <param name="clientRequestFunc">The specific client request function.</param>
     /// <param name="additionalMetadata">The additional metadata, if any.</param>
     /// <returns>A Task.</returns>
-    private static async Task TestHandlerSuccess(Func<Foobar.FoobarClient, Metadata, Task> clientRequestFunc, Metadata additionalMetadata = null)
+    private static async Task TestHandlerSuccess(Func<Foobar.FoobarClient, Metadata?, Task> clientRequestFunc, Metadata? additionalMetadata = null)
     {
         // starts the server with the server interceptor
         var testTags = new TestActivityTags();
@@ -113,6 +113,7 @@ private static async Task TestHandlerSuccess(Func<Foobar.FoobarClient, Metadata,
 
             var activity = activityListener.Activity;
             GrpcCoreClientInterceptorTests.ValidateCommonActivityTags(activity, StatusCode.OK, interceptorOptions.RecordMessageEvents);
+            Assert.NotNull(activity);
             Assert.Equal(default, activity.ParentSpanId);
         }
 
@@ -130,6 +131,7 @@ private static async Task TestHandlerSuccess(Func<Foobar.FoobarClient, Metadata,
 
             var activity = activityListener.Activity;
             GrpcCoreClientInterceptorTests.ValidateCommonActivityTags(activity, StatusCode.OK, interceptorOptions.RecordMessageEvents);
+            Assert.NotNull(activity);
             Assert.Equal(FoobarService.DefaultParentFromTraceparentHeader.SpanId, activity.ParentSpanId);
         }
     }
@@ -140,7 +142,7 @@ private static async Task TestHandlerSuccess(Func<Foobar.FoobarClient, Metadata,
     /// <param name="clientRequestFunc">The specific client request function.</param>
     /// <param name="additionalMetadata">The additional metadata, if any.</param>
     /// <returns>A Task.</returns>
-    private static async Task TestHandlerFailure(Func<Foobar.FoobarClient, Metadata, Task> clientRequestFunc, Metadata additionalMetadata = null)
+    private static async Task TestHandlerFailure(Func<Foobar.FoobarClient, Metadata?, Task> clientRequestFunc, Metadata? additionalMetadata = null)
     {
         // starts the server with the server interceptor
         var testTags = new TestActivityTags();
@@ -161,6 +163,7 @@ private static async Task TestHandlerFailure(Func<Foobar.FoobarClient, Metadata,
 
         var activity = activityListener.Activity;
         GrpcCoreClientInterceptorTests.ValidateCommonActivityTags(activity, StatusCode.ResourceExhausted, interceptorOptions.RecordMessageEvents, interceptorOptions.RecordException);
+        Assert.NotNull(activity);
         Assert.Equal(FoobarService.DefaultParentFromTraceparentHeader.SpanId, activity.ParentSpanId);
     }
 }
diff --git a/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/InterceptorActivityListener.cs b/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/InterceptorActivityListener.cs
index 5a5c165881..78e749fcb9 100644
--- a/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/InterceptorActivityListener.cs
+++ b/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/InterceptorActivityListener.cs
@@ -41,7 +41,7 @@ public InterceptorActivityListener(TestActivityTags testTags)
     /// <summary>
     /// Gets the started Activity.
     /// </summary>
-    public Activity Activity { get; private set; }
+    public Activity? Activity { get; private set; }
 
     /// <inheritdoc/>
     public void Dispose()
diff --git a/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/OpenTelemetry.Instrumentation.GrpcCore.Tests.csproj b/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/OpenTelemetry.Instrumentation.GrpcCore.Tests.csproj
index ed572dc067..6dac68bae0 100644
--- a/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/OpenTelemetry.Instrumentation.GrpcCore.Tests.csproj
+++ b/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/OpenTelemetry.Instrumentation.GrpcCore.Tests.csproj
@@ -2,11 +2,10 @@
 
   <PropertyGroup>
     <TargetFramework>net6.0</TargetFramework>
-    <Nullable>disable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Grpc.Tools" Version="1.17.0" />
+    <PackageReference Include="Grpc.Tools" Version="2.38.0" />
     <PackageReference Include="Grpc" Version="[2.46.6,3.0)" />
   </ItemGroup>
 
diff --git a/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/TestActivityTags.cs b/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/TestActivityTags.cs
index 7f1425ab7a..76798b7c1b 100644
--- a/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/TestActivityTags.cs
+++ b/test/OpenTelemetry.Instrumentation.GrpcCore.Tests/TestActivityTags.cs
@@ -12,13 +12,13 @@ internal class TestActivityTags
 
     public TestActivityTags()
     {
-        this.Tags = new Dictionary<string, object>()
+        this.Tags = new Dictionary<string, object?>()
         {
             [ActivityIdentifierTag] = Guid.NewGuid(),
         };
     }
 
-    internal IReadOnlyDictionary<string, object> Tags { get; }
+    internal IReadOnlyDictionary<string, object?> Tags { get; }
 
     /// <summary>
     /// Checks whether the activity has test tags.