Enable nullable on server transports (#28348)

Author: JamesNK

src/Servers/Connections.Abstractions/src/IConnectionListener.cs

@@ -23,7 +23,7 @@ public interface IConnectionListener : IAsyncDisposable
         /// </summary>
         /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
         /// <returns>A <see cref="ValueTask{ConnectionContext}"/> that completes when a connection is accepted, yielding the <see cref="ConnectionContext" /> representing the connection.</returns>
-        ValueTask<ConnectionContext> AcceptAsync(CancellationToken cancellationToken = default);
+        ValueTask<ConnectionContext?> AcceptAsync(CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Stops listening for incoming connections.

src/Servers/Connections.Abstractions/src/IMulitplexedConnectionListener.cs

@@ -32,6 +32,6 @@ public interface IMultiplexedConnectionListener : IAsyncDisposable
         /// <param name="features">A feature collection to pass options when accepting a connection.</param>
         /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
         /// <returns>A <see cref="ValueTask{ConnectionContext}"/> that completes when a connection is accepted, yielding the <see cref="MultiplexedConnectionContext" /> representing the connection.</returns>
-        ValueTask<MultiplexedConnectionContext> AcceptAsync(IFeatureCollection? features = null, CancellationToken cancellationToken = default);
+        ValueTask<MultiplexedConnectionContext?> AcceptAsync(IFeatureCollection? features = null, CancellationToken cancellationToken = default);
     }
 }

src/Servers/Connections.Abstractions/src/MultiplexedConnectionContext.cs

@@ -18,7 +18,7 @@ public abstract class MultiplexedConnectionContext : BaseConnectionContext, IAsy
         /// </summary>
         /// <param name="cancellationToken"></param>
         /// <returns></returns>
-        public abstract ValueTask<ConnectionContext> AcceptAsync(CancellationToken cancellationToken = default);
+        public abstract ValueTask<ConnectionContext?> AcceptAsync(CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Creates an outbound connection 

src/Servers/Connections.Abstractions/src/PublicAPI.Shipped.txt

@@ -102,7 +102,7 @@ Microsoft.AspNetCore.Connections.IConnectionBuilder.Use(System.Func<Microsoft.As
 Microsoft.AspNetCore.Connections.IConnectionFactory
 Microsoft.AspNetCore.Connections.IConnectionFactory.ConnectAsync(System.Net.EndPoint! endpoint, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.ValueTask<Microsoft.AspNetCore.Connections.ConnectionContext!>
 Microsoft.AspNetCore.Connections.IConnectionListener
-Microsoft.AspNetCore.Connections.IConnectionListener.AcceptAsync(System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.ValueTask<Microsoft.AspNetCore.Connections.ConnectionContext!>
+Microsoft.AspNetCore.Connections.IConnectionListener.AcceptAsync(System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.ValueTask<Microsoft.AspNetCore.Connections.ConnectionContext?>
 Microsoft.AspNetCore.Connections.IConnectionListener.EndPoint.get -> System.Net.EndPoint!
 Microsoft.AspNetCore.Connections.IConnectionListener.UnbindAsync(System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.ValueTask
 Microsoft.AspNetCore.Connections.IConnectionListenerFactory

src/Servers/Connections.Abstractions/src/PublicAPI.Unshipped.txt

@@ -6,7 +6,7 @@ Microsoft.AspNetCore.Connections.Experimental.IMultiplexedConnectionBuilder.Use(
 Microsoft.AspNetCore.Connections.Experimental.IMultiplexedConnectionFactory
 Microsoft.AspNetCore.Connections.Experimental.IMultiplexedConnectionFactory.ConnectAsync(System.Net.EndPoint! endpoint, Microsoft.AspNetCore.Http.Features.IFeatureCollection? features = null, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.ValueTask<Microsoft.AspNetCore.Connections.Experimental.MultiplexedConnectionContext!>
 Microsoft.AspNetCore.Connections.Experimental.IMultiplexedConnectionListener
-Microsoft.AspNetCore.Connections.Experimental.IMultiplexedConnectionListener.AcceptAsync(Microsoft.AspNetCore.Http.Features.IFeatureCollection? features = null, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.ValueTask<Microsoft.AspNetCore.Connections.Experimental.MultiplexedConnectionContext!>
+Microsoft.AspNetCore.Connections.Experimental.IMultiplexedConnectionListener.AcceptAsync(Microsoft.AspNetCore.Http.Features.IFeatureCollection? features = null, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.ValueTask<Microsoft.AspNetCore.Connections.Experimental.MultiplexedConnectionContext?>
 Microsoft.AspNetCore.Connections.Experimental.IMultiplexedConnectionListener.EndPoint.get -> System.Net.EndPoint!
 Microsoft.AspNetCore.Connections.Experimental.IMultiplexedConnectionListener.UnbindAsync(System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.ValueTask
 Microsoft.AspNetCore.Connections.Experimental.IMultiplexedConnectionListenerFactory
@@ -19,5 +19,5 @@ Microsoft.AspNetCore.Connections.Experimental.MultiplexedConnectionBuilder.Use(S
 Microsoft.AspNetCore.Connections.Experimental.MultiplexedConnectionContext
 Microsoft.AspNetCore.Connections.Experimental.MultiplexedConnectionContext.MultiplexedConnectionContext() -> void
 Microsoft.AspNetCore.Connections.Experimental.MultiplexedConnectionDelegate
-abstract Microsoft.AspNetCore.Connections.Experimental.MultiplexedConnectionContext.AcceptAsync(System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.ValueTask<Microsoft.AspNetCore.Connections.ConnectionContext!>
+abstract Microsoft.AspNetCore.Connections.Experimental.MultiplexedConnectionContext.AcceptAsync(System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.ValueTask<Microsoft.AspNetCore.Connections.ConnectionContext?>
 abstract Microsoft.AspNetCore.Connections.Experimental.MultiplexedConnectionContext.ConnectAsync(Microsoft.AspNetCore.Http.Features.IFeatureCollection? features = null, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.ValueTask<Microsoft.AspNetCore.Connections.ConnectionContext!>

src/Servers/Kestrel/Core/src/Internal/Infrastructure/IConnectionListenerOfT.cs

@@ -18,6 +18,6 @@ internal interface IConnectionListener<T> : IConnectionListenerBase where T : Ba
         /// </summary>
         /// <param name="cancellationToken">The token to monitor for cancellation requests.</param>
         /// <returns>A <see cref="ValueTask{T}"/> that completes when a connection is accepted, yielding the <see cref="BaseConnectionContext" /> representing the connection.</returns>
-        ValueTask<T> AcceptAsync(CancellationToken cancellationToken = default);
+        ValueTask<T?> AcceptAsync(CancellationToken cancellationToken = default);
     }
 }

src/Servers/Kestrel/Core/src/Internal/Infrastructure/TransportManager.cs

@@ -162,7 +162,7 @@ public GenericConnectionListener(IConnectionListener connectionListener)
 
             public EndPoint EndPoint => _connectionListener.EndPoint;
 
-            public ValueTask<ConnectionContext> AcceptAsync(CancellationToken cancellationToken = default)
+            public ValueTask<ConnectionContext?> AcceptAsync(CancellationToken cancellationToken = default)
                  => _connectionListener.AcceptAsync(cancellationToken);
 
             public ValueTask UnbindAsync(CancellationToken cancellationToken = default)
@@ -183,7 +183,7 @@ public GenericMultiplexedConnectionListener(IMultiplexedConnectionListener multi
 
             public EndPoint EndPoint => _multiplexedConnectionListener.EndPoint;
 
-            public ValueTask<MultiplexedConnectionContext> AcceptAsync(CancellationToken cancellationToken = default)
+            public ValueTask<MultiplexedConnectionContext?> AcceptAsync(CancellationToken cancellationToken = default)
                  => _multiplexedConnectionListener.AcceptAsync(features: null, cancellationToken);
 
             public ValueTask UnbindAsync(CancellationToken cancellationToken = default)

src/Servers/Kestrel/Transport.Quic/src/Internal/FakeTlsConnectionFeature.cs

@@ -15,9 +15,9 @@ public FakeTlsConnectionFeature()
         {
         }
 
-        public X509Certificate2 ClientCertificate { get => throw new NotImplementedException(); set => throw new NotImplementedException(); }
+        public X509Certificate2? ClientCertificate { get => throw new NotImplementedException(); set => throw new NotImplementedException(); }
 
-        public Task<X509Certificate2> GetClientCertificateAsync(CancellationToken cancellationToken)
+        public Task<X509Certificate2?> GetClientCertificateAsync(CancellationToken cancellationToken)
         {
             throw new NotImplementedException();
         }

src/Servers/Kestrel/Transport.Quic/src/Internal/QuicConnectionContext.cs

@@ -74,7 +74,7 @@ public override void Abort(ConnectionAbortedException abortReason)
             _closeTask = _connection.CloseAsync(errorCode: Error);
         }
 
-        public override async ValueTask<ConnectionContext> AcceptAsync(CancellationToken cancellationToken = default)
+        public override async ValueTask<ConnectionContext?> AcceptAsync(CancellationToken cancellationToken = default)
         {
             try
             {
@@ -90,7 +90,7 @@ public override async ValueTask<ConnectionContext> AcceptAsync(CancellationToken
             return null;
         }
 
-        public override ValueTask<ConnectionContext> ConnectAsync(IFeatureCollection features = null, CancellationToken cancellationToken = default)
+        public override ValueTask<ConnectionContext> ConnectAsync(IFeatureCollection? features = null, CancellationToken cancellationToken = default)
         {
             QuicStream quicStream;
 

src/Servers/Kestrel/Transport.Quic/src/Internal/QuicConnectionListener.cs

@@ -26,6 +26,11 @@ internal class QuicConnectionListener : IMultiplexedConnectionListener, IAsyncDi
 
         public QuicConnectionListener(QuicTransportOptions options, IQuicTrace log, EndPoint endpoint)
         {
+            if (options.Alpn == null)
+            {
+                throw new InvalidOperationException("QuicTransportOptions.Alpn must be configured with a value.");
+            }
+
             _log = log;
             _context = new QuicTransportContext(_log, options);
             EndPoint = endpoint;
@@ -46,7 +51,7 @@ public QuicConnectionListener(QuicTransportOptions options, IQuicTrace log, EndP
 
         public EndPoint EndPoint { get; set; }
 
-        public async ValueTask<MultiplexedConnectionContext> AcceptAsync(IFeatureCollection features = null, CancellationToken cancellationToken = default)
+        public async ValueTask<MultiplexedConnectionContext?> AcceptAsync(IFeatureCollection? features = null, CancellationToken cancellationToken = default)
         {
             try
             {