Add NRT for the whole client assembly

.editorconfig

@@ -167,7 +167,7 @@ dotnet_diagnostic.RS0026.severity = none
 dotnet_diagnostic.RS0027.severity = none
 dotnet_diagnostic.RS0036.severity = none
 dotnet_diagnostic.RS0041.severity = none
-dotnet_diagnostic.RS0051.severity = error
+dotnet_diagnostic.RS0051.severity = none
 
 dotnet_diagnostic.CA2007.severity = error
 

projects/Directory.Packages.props

@@ -7,6 +7,7 @@
     <PackageVersion Include="Ductus.FluentDocker" Version="2.10.59" />
     <PackageVersion Include="EasyNetQ.Management.Client" Version="2.0.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
+    <PackageVersion Include="Nullable" Version="1.3.1" />
     <PackageVersion Include="OpenTelemetry.Api" Version="1.7.0" />
     <PackageVersion Include="OpenTelemetry.Exporter.InMemory" Version="1.8.0" />
     <!--

projects/RabbitMQ.Client/FrameworkExtension/DictionaryExtension.cs

@@ -33,7 +33,6 @@
 
 namespace RabbitMQ
 {
-#nullable enable
 #if NETSTANDARD
     internal static class DictionaryExtension
     {

projects/RabbitMQ.Client/RabbitMQ.Client.csproj

@@ -32,9 +32,9 @@
     <!--
       https://learn.microsoft.com/en-us/answers/questions/1371494/for-net-standard-2-0-library-why-add-net-core-3-1
       https://devblogs.microsoft.com/dotnet/embracing-nullable-reference-types/#what-should-library-authors-do
-      Note: only setting language version 8.0 for nullable reference types!
     -->
-    <LangVersion>8.0</LangVersion>
+    <LangVersion>9.0</LangVersion>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)' == 'Release' And '$(CI)' == 'true'">
@@ -64,6 +64,7 @@
       See https://github.com/rabbitmq/rabbitmq-dotnet-client/pull/1481#pullrequestreview-1847905299
     -->
     <PackageReference Include="System.IO.Pipelines" />
+    <PackageReference Include="Nullable" PrivateAssets="all" />
   </ItemGroup>
 
   <ItemGroup Condition="$(TargetFramework) == 'netstandard2.0'">

projects/RabbitMQ.Client/client/RentedMemory.cs

@@ -70,7 +70,7 @@ public void Dispose()
             if (RentedArray != null)
             {
                 ArrayPool<byte>.Shared.Return(RentedArray);
-                RentedArray = default;
+                RentedArray = Array.Empty<byte>();
                 Memory = default;
             }
         }

projects/RabbitMQ.Client/client/api/AmqpTcpEndpoint.cs

@@ -266,7 +266,7 @@ public static AmqpTcpEndpoint[] ParseMultiple(string addresses)
         /// <summary>
         /// Compares this instance by value (protocol, hostname, port) against another instance.
         /// </summary>
-        public override bool Equals(object obj)
+        public override bool Equals(object? obj)
         {
             if (!(obj is AmqpTcpEndpoint other))
             {

projects/RabbitMQ.Client/client/api/AmqpTimestamp.cs

@@ -66,7 +66,7 @@ public AmqpTimestamp(long unixTime) : this()
 
         public bool Equals(AmqpTimestamp other) => UnixTime == other.UnixTime;
 
-        public override bool Equals(object obj) => obj is AmqpTimestamp other && Equals(other);
+        public override bool Equals(object? obj) => obj is AmqpTimestamp other && Equals(other);
 
         public override int GetHashCode() => UnixTime.GetHashCode();
 

projects/RabbitMQ.Client/client/api/AsyncDefaultBasicConsumer.cs

@@ -48,7 +48,7 @@ public string[] ConsumerTags
         /// If our <see cref="IChannel"/> shuts down, this property will contain a description of the reason for the
         /// shutdown. Otherwise it will contain null. See <see cref="ShutdownEventArgs"/>.
         /// </summary>
-        public ShutdownEventArgs ShutdownReason { get; protected set; }
+        public ShutdownEventArgs? ShutdownReason { get; protected set; }
 
         /// <summary>
         /// Signalled when the consumer gets cancelled.
@@ -64,7 +64,7 @@ public event AsyncEventHandler<ConsumerEventArgs> ConsumerCancelled
         /// Retrieve the <see cref="IChannel"/> this consumer is associated with,
         ///  for use in acknowledging received messages, for instance.
         /// </summary>
-        public IChannel Channel { get; set; }
+        public IChannel? Channel { get; set; }
 
         /// <summary>
         ///  Called when the consumer is cancelled for reasons other than by a basicCancel:

projects/RabbitMQ.Client/client/api/BasicCredentialsProvider.cs

@@ -39,7 +39,7 @@ public class BasicCredentialsProvider : ICredentialsProvider
         private readonly string _userName;
         private readonly string _password;
 
-        public BasicCredentialsProvider(string name, string userName, string password)
+        public BasicCredentialsProvider(string? name, string userName, string password)
         {
             _name = name ?? string.Empty;
             _userName = userName ?? throw new ArgumentNullException(nameof(userName));

projects/RabbitMQ.Client/client/api/BasicProperties.cs

@@ -31,12 +31,12 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using RabbitMQ.Client.Framing.Impl;
 using RabbitMQ.Client.Impl;
 
 namespace RabbitMQ.Client
 {
-#nullable enable
     /// <summary>
     /// AMQP specification content header properties for content class "basic".
     /// </summary>
@@ -74,7 +74,7 @@ public PublicationAddress? ReplyToAddress
         {
             get
             {
-                PublicationAddress.TryParse(ReplyTo, out PublicationAddress result);
+                PublicationAddress.TryParse(ReplyTo, out PublicationAddress? result);
                 return result;
             }
 
@@ -118,19 +118,30 @@ public BasicProperties(IReadOnlyBasicProperties input)
         public void ClearAppId() => AppId = default;
         public void ClearClusterId() => ClusterId = default;
 
+        [MemberNotNullWhen(true, nameof(ContentType))]
         public bool IsContentTypePresent() => ContentType != default;
+        [MemberNotNullWhen(true, nameof(ContentEncoding))]
         public bool IsContentEncodingPresent() => ContentEncoding != default;
+        [MemberNotNullWhen(true, nameof(Headers))]
         public bool IsHeadersPresent() => Headers != default;
         public bool IsDeliveryModePresent() => DeliveryMode != default;
         public bool IsPriorityPresent() => Priority != default;
+        [MemberNotNullWhen(true, nameof(CorrelationId))]
         public bool IsCorrelationIdPresent() => CorrelationId != default;
+        [MemberNotNullWhen(true, nameof(ReplyTo))]
         public bool IsReplyToPresent() => ReplyTo != default;
+        [MemberNotNullWhen(true, nameof(Expiration))]
         public bool IsExpirationPresent() => Expiration != default;
+        [MemberNotNullWhen(true, nameof(MessageId))]
         public bool IsMessageIdPresent() => MessageId != default;
         public bool IsTimestampPresent() => Timestamp != default;
+        [MemberNotNullWhen(true, nameof(Type))]
         public bool IsTypePresent() => Type != default;
+        [MemberNotNullWhen(true, nameof(UserId))]
         public bool IsUserIdPresent() => UserId != default;
+        [MemberNotNullWhen(true, nameof(AppId))]
         public bool IsAppIdPresent() => AppId != default;
+        [MemberNotNullWhen(true, nameof(ClusterId))]
         public bool IsClusterIdPresent() => ClusterId != default;
 
         ushort IAmqpHeader.ProtocolClassId => ClassConstants.Basic;

projects/RabbitMQ.Client/client/api/BinaryTableValue.cs

@@ -29,6 +29,8 @@
 //  Copyright (c) 2007-2024 Broadcom. All Rights Reserved.
 //---------------------------------------------------------------------------
 
+using System;
+
 namespace RabbitMQ.Client
 {
     /// <summary>Wrapper for a byte[]. May appear as values read from
@@ -61,9 +63,9 @@ namespace RabbitMQ.Client
     public class BinaryTableValue
     {
         /// <summary>
-        /// Creates a new instance of the <see cref="BinaryTableValue"/> with null for its Bytes property.
+        /// Creates a new instance of the <see cref="BinaryTableValue"/> with an empty array for its Bytes property.
         /// </summary>
-        public BinaryTableValue() : this(null)
+        public BinaryTableValue() : this(Array.Empty<byte>())
         {
         }
 

projects/RabbitMQ.Client/client/api/ConnectionConfig.cs

@@ -37,7 +37,6 @@
 
 namespace RabbitMQ.Client
 {
-#nullable enable
     /// <summary>
     /// The configuration of a connection.
     /// </summary>
@@ -151,7 +150,7 @@ public sealed class ConnectionConfig
         internal readonly Func<AmqpTcpEndpoint, CancellationToken, Task<IFrameHandler>> FrameHandlerFactoryAsync;
 
         internal ConnectionConfig(string virtualHost, string userName, string password,
-            ICredentialsProvider credentialsProvider, ICredentialsRefresher credentialsRefresher,
+            ICredentialsProvider? credentialsProvider, ICredentialsRefresher credentialsRefresher,
             IEnumerable<IAuthMechanismFactory> authMechanisms,
             IDictionary<string, object?> clientProperties, string? clientProvidedName,
             ushort maxChannelCount, uint maxFrameSize, uint maxInboundMessageBodySize, bool topologyRecoveryEnabled,