[Group 4] Enable nullable annotations for `Microsoft.Extensions.Http` (#66891)

* Annotate things

* InnerHandler not null

* Fix build

src/libraries/Microsoft.Extensions.Http/ref/Microsoft.Extensions.Http.cs

@@ -66,7 +66,8 @@ public abstract partial class HttpMessageHandlerBuilder
     {
         protected HttpMessageHandlerBuilder() { }
         public abstract System.Collections.Generic.IList<System.Net.Http.DelegatingHandler> AdditionalHandlers { get; }
-        public abstract string Name { get; set; }
+        [System.Diagnostics.CodeAnalysis.DisallowNull]
+        public abstract string? Name { get; set; }
         public abstract System.Net.Http.HttpMessageHandler PrimaryHandler { get; set; }
         public virtual System.IServiceProvider Services { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
         public abstract System.Net.Http.HttpMessageHandler Build();

src/libraries/Microsoft.Extensions.Http/ref/Microsoft.Extensions.Http.csproj

 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppMinimum);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>

src/libraries/Microsoft.Extensions.Http/src/ActiveHandlerTrackingEntry.cs

@@ -13,16 +13,16 @@ namespace Microsoft.Extensions.Http
     // for the 'expiry' pool simplifies the threading requirements significantly.
     internal sealed class ActiveHandlerTrackingEntry
     {
-        private static readonly TimerCallback _timerCallback = (s) => ((ActiveHandlerTrackingEntry)s).Timer_Tick();
+        private static readonly TimerCallback _timerCallback = (s) => ((ActiveHandlerTrackingEntry)s!).Timer_Tick();
         private readonly object _lock;
         private bool _timerInitialized;
-        private Timer _timer;
-        private TimerCallback _callback;
+        private Timer? _timer;
+        private TimerCallback? _callback;
 
         public ActiveHandlerTrackingEntry(
             string name,
             LifetimeTrackingHttpMessageHandler handler,
-            IServiceScope scope,
+            IServiceScope? scope,
             TimeSpan lifetime)
         {
             Name = name;
@@ -39,7 +39,7 @@ internal sealed class ActiveHandlerTrackingEntry
 
         public string Name { get; }
 
-        public IServiceScope Scope { get; }
+        public IServiceScope? Scope { get; }
 
         public void StartExpiryTimer(TimerCallback callback)
         {

src/libraries/Microsoft.Extensions.Http/src/DefaultHttpClientFactory.cs

@@ -17,7 +17,7 @@ namespace Microsoft.Extensions.Http
 {
     internal class DefaultHttpClientFactory : IHttpClientFactory, IHttpMessageHandlerFactory
     {
-        private static readonly TimerCallback _cleanupCallback = (s) => ((DefaultHttpClientFactory)s).CleanupTimer_Tick();
+        private static readonly TimerCallback _cleanupCallback = (s) => ((DefaultHttpClientFactory)s!).CleanupTimer_Tick();
         private readonly ILogger _logger;
         private readonly IServiceProvider _services;
         private readonly IServiceScopeFactory _scopeFactory;
@@ -37,7 +37,7 @@ internal class DefaultHttpClientFactory : IHttpClientFactory, IHttpMessageHandle
         //
         // There's no need for the factory itself to be disposable. If you stop using it, eventually everything will
         // get reclaimed.
-        private Timer _cleanupTimer;
+        private Timer? _cleanupTimer;
         private readonly object _cleanupTimerLock;
         private readonly object _cleanupActiveLock;
 
@@ -116,7 +116,7 @@ public HttpMessageHandler CreateHandler(string name!!)
         internal ActiveHandlerTrackingEntry CreateHandlerEntry(string name)
         {
             IServiceProvider services = _services;
-            var scope = (IServiceScope)null;
+            var scope = (IServiceScope?)null;
 
             HttpClientFactoryOptions options = _optionsMonitor.Get(name);
             if (!options.SuppressHandlerScope)
@@ -169,15 +169,15 @@ void Configure(HttpMessageHandlerBuilder b)
         }
 
         // Internal for tests
-        internal void ExpiryTimer_Tick(object state)
+        internal void ExpiryTimer_Tick(object? state)
         {
-            var active = (ActiveHandlerTrackingEntry)state;
+            var active = (ActiveHandlerTrackingEntry)state!;
 
             // The timer callback should be the only one removing from the active collection. If we can't find
             // our entry in the collection, then this is a bug.
-            bool removed = _activeHandlers.TryRemove(active.Name, out Lazy<ActiveHandlerTrackingEntry> found);
+            bool removed = _activeHandlers.TryRemove(active.Name, out Lazy<ActiveHandlerTrackingEntry>? found);
             Debug.Assert(removed, "Entry not found. We should always be able to remove the entry");
-            Debug.Assert(object.ReferenceEquals(active, found.Value), "Different entry found. The entry should not have been replaced");
+            Debug.Assert(object.ReferenceEquals(active, found!.Value), "Different entry found. The entry should not have been replaced");
 
             // At this point the handler is no longer 'active' and will not be handed out to any new clients.
             // However we haven't dropped our strong reference to the handler, so we can't yet determine if
@@ -216,7 +216,7 @@ internal virtual void StopCleanupTimer()
         {
             lock (_cleanupTimerLock)
             {
-                _cleanupTimer.Dispose();
+                _cleanupTimer!.Dispose();
                 _cleanupTimer = null;
             }
         }
@@ -257,7 +257,7 @@ internal void CleanupTimer_Tick()
                 for (int i = 0; i < initialCount; i++)
                 {
                     // Since we're the only one removing from _expired, TryDequeue must always succeed.
-                    _expiredHandlers.TryDequeue(out ExpiredHandlerTrackingEntry entry);
+                    _expiredHandlers.TryDequeue(out ExpiredHandlerTrackingEntry? entry);
                     Debug.Assert(entry != null, "Entry was null, we should always get an entry back from TryDequeue");
 
                     if (entry.CanDispose)
@@ -305,12 +305,12 @@ public static class EventIds
                 public static readonly EventId HandlerExpired = new EventId(103, "HandlerExpired");
             }
 
-            private static readonly Action<ILogger, int, Exception> _cleanupCycleStart = LoggerMessage.Define<int>(
+            private static readonly Action<ILogger, int, Exception?> _cleanupCycleStart = LoggerMessage.Define<int>(
                 LogLevel.Debug,
                 EventIds.CleanupCycleStart,
                 "Starting HttpMessageHandler cleanup cycle with {InitialCount} items");
 
-            private static readonly Action<ILogger, double, int, int, Exception> _cleanupCycleEnd = LoggerMessage.Define<double, int, int>(
+            private static readonly Action<ILogger, double, int, int, Exception?> _cleanupCycleEnd = LoggerMessage.Define<double, int, int>(
                 LogLevel.Debug,
                 EventIds.CleanupCycleEnd,
                 "Ending HttpMessageHandler cleanup cycle after {ElapsedMilliseconds}ms - processed: {DisposedCount} items - remaining: {RemainingItems} items");
@@ -320,7 +320,7 @@ public static class EventIds
                 EventIds.CleanupItemFailed,
                 "HttpMessageHandler.Dispose() threw an unhandled exception for client: '{ClientName}'");
 
-            private static readonly Action<ILogger, double, string, Exception> _handlerExpired = LoggerMessage.Define<double, string>(
+            private static readonly Action<ILogger, double, string, Exception?> _handlerExpired = LoggerMessage.Define<double, string>(
                 LogLevel.Debug,
                 EventIds.HandlerExpired,
                 "HttpMessageHandler expired after {HandlerLifetime}ms for client '{ClientName}'");

src/libraries/Microsoft.Extensions.Http/src/DefaultHttpMessageHandlerBuilder.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Net.Http;
 
 namespace Microsoft.Extensions.Http
@@ -14,9 +15,10 @@ public DefaultHttpMessageHandlerBuilder(IServiceProvider services)
             Services = services;
         }
 
-        private string _name;
+        private string? _name;
 
-        public override string Name
+        [DisallowNull]
+        public override string? Name
         {
             get => _name;
             set

src/libraries/Microsoft.Extensions.Http/src/DefaultTypedHttpClientFactory.cs

@@ -33,15 +33,15 @@ public class Cache
         {
             private static readonly Func<ObjectFactory> _createActivator = () => ActivatorUtilities.CreateFactory(typeof(TClient), new Type[] { typeof(HttpClient), });
 
-            private ObjectFactory _activator;
+            private ObjectFactory? _activator;
             private bool _initialized;
-            private object _lock;
+            private object? _lock;
 
             public ObjectFactory Activator => LazyInitializer.EnsureInitialized(
                 ref _activator,
                 ref _initialized,
                 ref _lock,
-                _createActivator);
+                _createActivator)!;
         }
     }
 }

src/libraries/Microsoft.Extensions.Http/src/DependencyInjection/HttpClientBuilderExtensions.cs

@@ -488,11 +488,11 @@ public static IHttpClientBuilder SetHandlerLifetime(this IHttpClientBuilder buil
         // See comments on HttpClientMappingRegistry.
         private static void ReserveClient(IHttpClientBuilder builder, Type type, string name, bool validateSingleType)
         {
-            var registry = (HttpClientMappingRegistry)builder.Services.Single(sd => sd.ServiceType == typeof(HttpClientMappingRegistry)).ImplementationInstance;
+            var registry = (HttpClientMappingRegistry?)builder.Services.Single(sd => sd.ServiceType == typeof(HttpClientMappingRegistry)).ImplementationInstance;
             Debug.Assert(registry != null);
 
             // Check for same name registered to two types. This won't work because we rely on named options for the configuration.
-            if (registry.NamedClientRegistrations.TryGetValue(name, out Type otherType) &&
+            if (registry.NamedClientRegistrations.TryGetValue(name, out Type? otherType) &&
 
                 // Allow using the same name with multiple types in some cases (see callers).
                 validateSingleType &&

src/libraries/Microsoft.Extensions.Http/src/DependencyInjection/HttpClientFactoryServiceCollectionExtensions.cs

@@ -508,7 +508,7 @@ public static IHttpClientBuilder AddHttpClient(this IServiceCollection services!
 
             var builder = new DefaultHttpClientBuilder(services, name);
             builder.ConfigureHttpClient(configureClient);
-            builder.AddTypedClientCore<TClient>(validateSingleType: false); // name was explictly provided
+            builder.AddTypedClientCore<TClient>(validateSingleType: false); // name was explicitly provided
             return builder;
         }
 

src/libraries/Microsoft.Extensions.Http/src/ExpiredHandlerTrackingEntry.cs

@@ -20,7 +20,7 @@ public ExpiredHandlerTrackingEntry(ActiveHandlerTrackingEntry other)
             Scope = other.Scope;
 
             _livenessTracker = new WeakReference(other.Handler);
-            InnerHandler = other.Handler.InnerHandler;
+            InnerHandler = other.Handler.InnerHandler!;
         }
 
         public bool CanDispose => !_livenessTracker.IsAlive;
@@ -29,6 +29,6 @@ public ExpiredHandlerTrackingEntry(ActiveHandlerTrackingEntry other)
 
         public string Name { get; }
 
-        public IServiceScope Scope { get; }
+        public IServiceScope? Scope { get; }
     }
 }

src/libraries/Microsoft.Extensions.Http/src/HttpMessageHandlerBuilder.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Net.Http;
 
@@ -26,7 +27,8 @@ public abstract class HttpMessageHandlerBuilder
         /// and is public for unit testing purposes only. Setting the <see cref="Name"/> outside of
         /// testing scenarios may have unpredictable results.
         /// </remarks>
-        public abstract string Name { get; set; }
+        [DisallowNull]
+        public abstract string? Name { get; set; }
 
         /// <summary>
         /// Gets or sets the primary <see cref="HttpMessageHandler"/>.
@@ -50,7 +52,7 @@ public abstract class HttpMessageHandlerBuilder
         /// (default) this will be a reference to a scoped service provider that has the same
         /// lifetime as the handler being created.
         /// </remarks>
-        public virtual IServiceProvider Services { get; }
+        public virtual IServiceProvider Services { get; } = null!;
 
         /// <summary>
         /// Creates an <see cref="HttpMessageHandler"/>.

src/libraries/Microsoft.Extensions.Http/src/Logging/HttpHeadersLogValue.cs

@@ -14,10 +14,10 @@ internal sealed class HttpHeadersLogValue : IReadOnlyList<KeyValuePair<string, o
         private readonly Kind _kind;
         private readonly Func<string, bool> _shouldRedactHeaderValue;
 
-        private string _formatted;
-        private List<KeyValuePair<string, object>> _values;
+        private string? _formatted;
+        private List<KeyValuePair<string, object>>? _values;
 
-        public HttpHeadersLogValue(Kind kind, HttpHeaders headers, HttpHeaders contentHeaders, Func<string, bool> shouldRedactHeaderValue)
+        public HttpHeadersLogValue(Kind kind, HttpHeaders headers, HttpHeaders? contentHeaders, Func<string, bool> shouldRedactHeaderValue)
         {
             _kind = kind;
             _shouldRedactHeaderValue = shouldRedactHeaderValue;
@@ -28,7 +28,7 @@ public HttpHeadersLogValue(Kind kind, HttpHeaders headers, HttpHeaders contentHe
 
         public HttpHeaders Headers { get; }
 
-        public HttpHeaders ContentHeaders { get; }
+        public HttpHeaders? ContentHeaders { get; }
 
         private List<KeyValuePair<string, object>> Values
         {

src/libraries/Microsoft.Extensions.Http/src/Logging/LoggingHttpMessageHandler.cs

@@ -16,7 +16,7 @@ namespace Microsoft.Extensions.Http.Logging
     public class LoggingHttpMessageHandler : DelegatingHandler
     {
         private ILogger _logger;
-        private readonly HttpClientFactoryOptions _options;
+        private readonly HttpClientFactoryOptions? _options;
 
         private static readonly Func<string, bool> _shouldNotRedactHeaderValue = (header) => false;
 
@@ -72,13 +72,13 @@ public static class EventIds
 
             private static readonly LogDefineOptions _skipEnabledCheckLogDefineOptions = new LogDefineOptions() { SkipEnabledCheck = true };
 
-            private static readonly Action<ILogger, HttpMethod, string, Exception> _requestStart = LoggerMessage.Define<HttpMethod, string>(
+            private static readonly Action<ILogger, HttpMethod, string?, Exception?> _requestStart = LoggerMessage.Define<HttpMethod, string?>(
                 LogLevel.Information,
                 EventIds.RequestStart,
                 "Sending HTTP request {HttpMethod} {Uri}",
                 _skipEnabledCheckLogDefineOptions);
 
-            private static readonly Action<ILogger, double, int, Exception> _requestEnd = LoggerMessage.Define<double, int>(
+            private static readonly Action<ILogger, double, int, Exception?> _requestEnd = LoggerMessage.Define<double, int>(
                 LogLevel.Information,
                 EventIds.RequestEnd,
                 "Received HTTP response headers after {ElapsedMilliseconds}ms - {StatusCode}");

src/libraries/Microsoft.Extensions.Http/src/Logging/LoggingScopeHttpMessageHandler.cs

@@ -16,7 +16,7 @@ namespace Microsoft.Extensions.Http.Logging
     public class LoggingScopeHttpMessageHandler : DelegatingHandler
     {
         private ILogger _logger;
-        private readonly HttpClientFactoryOptions _options;
+        private readonly HttpClientFactoryOptions? _options;
 
         private static readonly Func<string, bool> _shouldNotRedactHeaderValue = (header) => false;
 
@@ -72,19 +72,19 @@ public static class EventIds
                 public static readonly EventId ResponseHeader = new EventId(103, "RequestPipelineResponseHeader");
             }
 
-            private static readonly Func<ILogger, HttpMethod, string, IDisposable> _beginRequestPipelineScope = LoggerMessage.DefineScope<HttpMethod, string>("HTTP {HttpMethod} {Uri}");
+            private static readonly Func<ILogger, HttpMethod, string?, IDisposable?> _beginRequestPipelineScope = LoggerMessage.DefineScope<HttpMethod, string?>("HTTP {HttpMethod} {Uri}");
 
-            private static readonly Action<ILogger, HttpMethod, string, Exception> _requestPipelineStart = LoggerMessage.Define<HttpMethod, string>(
+            private static readonly Action<ILogger, HttpMethod, string?, Exception?> _requestPipelineStart = LoggerMessage.Define<HttpMethod, string?>(
                 LogLevel.Information,
                 EventIds.PipelineStart,
                 "Start processing HTTP request {HttpMethod} {Uri}");
 
-            private static readonly Action<ILogger, double, int, Exception> _requestPipelineEnd = LoggerMessage.Define<double, int>(
+            private static readonly Action<ILogger, double, int, Exception?> _requestPipelineEnd = LoggerMessage.Define<double, int>(
                 LogLevel.Information,
                 EventIds.PipelineEnd,
                 "End processing HTTP request after {ElapsedMilliseconds}ms - {StatusCode}");
 
-            public static IDisposable BeginRequestPipelineScope(ILogger logger, HttpRequestMessage request)
+            public static IDisposable? BeginRequestPipelineScope(ILogger logger, HttpRequestMessage request)
             {
                 return _beginRequestPipelineScope(logger, request.Method, GetUriString(request.RequestUri));
             }

src/libraries/Microsoft.Extensions.Http/src/Microsoft.Extensions.Http.csproj

@@ -2,11 +2,11 @@
 
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppMinimum);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
+    <Nullable>enable</Nullable>
     <EnableDefaultItems>true</EnableDefaultItems>
     <!-- Use targeting pack references instead of granular ones in the project file. -->
     <DisableImplicitAssemblyReferences>false</DisableImplicitAssemblyReferences>
     <IsPackable>true</IsPackable>
-    <Nullable>Annotations</Nullable>
     <PackageDescription>The HttpClient factory is a pattern for configuring and retrieving named HttpClients in a composable way. The HttpClient factory provides extensibility to plug in DelegatingHandlers that address cross-cutting concerns such as service location, load balancing, and reliability. The default HttpClient factory provides built-in diagnostics and logging and manages the lifetimes of connections in a performant way.
 
 Commonly Used Types: