Fixed HttpClient Injection which was slightly broken with a hard reference

Author: Tewr

src/BlazorWorker.Demo/Client/Pages/CoreExample.razor

@@ -94,7 +94,6 @@
                     var result = double.Parse(message.Substring($"{CoreMathsService.ResultMessage}:".Length).Trim());
                     output += $"{rn}{LogDate()} EstimatePI({piIterations}) = {result}";
                     StateHasChanged();
-                    StateHasChanged();
                 }
             }
 

src/BlazorWorker.Demo/Client/Pages/Http.razor

@@ -53,7 +53,7 @@
                 sw.Start();
                 backgroundService = await worker.CreateBackgroundServiceAsync<WebCallerService>(
                     options => options
-                        .UseConventionalServiceAssembly()
+                        .AddConventionalAssemblyOfService()
                         .AddHttpClient()
                 );
 

src/BlazorWorker.ServiceFactory/WorkerBackgroundServiceExtensions.cs

@@ -22,7 +22,7 @@ public static async Task<IWorkerBackgroundService<T>> CreateBackgroundServiceAsy
             var proxy = new WorkerBackgroundServiceProxy<T>(webWorkerProxy, new WebWorkerOptions());
             if (workerInitOptions == null)
             {
-                workerInitOptions = new WorkerInitOptions().AddConventionalDependencyFor<T>();
+                workerInitOptions = new WorkerInitOptions().AddAssemblyOf<T>();
             }
 
             await proxy.InitAsync(workerInitOptions);

src/BlazorWorker.ServiceFactory/WorkerBackgroundServiceProxy.cs

@@ -98,9 +98,9 @@ public async Task InitAsync(WorkerInitOptions workerInitOptions = null)
             {
                 initWorkerTask = new TaskCompletionSource<bool>();
 
-                if (workerInitOptions.ConventionalServiceAssembly)
+                if (workerInitOptions.UseConventionalServiceAssembly)
                 {
-                    workerInitOptions.AddConventionalDependencyFor<T>();
+                    workerInitOptions.AddAssemblyOf<T>();
                 }
 
                 await this.worker.InitAsync(new WorkerInitOptions() {

src/BlazorWorker.WorkerCore/BlazorWorker.WorkerCore.xml

@@ -40,7 +40,7 @@ public WorkerInitOptions()
         /// <summary>
         /// If set to true, deducts the name of the assembly containing the service using the service type assembly name + dll extension as file name, and adds it as a dependency.
         /// </summary>
-        public bool ConventionalServiceAssembly { get; set; }
+        public bool UseConventionalServiceAssembly { get; set; }
 
         public WorkerInitOptions MergeWith(WorkerInitOptions initOptions)
         {
@@ -52,7 +52,7 @@ public WorkerInitOptions MergeWith(WorkerInitOptions initOptions)
                     .Concat(initOptions.DependentAssemblyFilenames)
                     .Distinct()
                     .ToArray(),
-                ConventionalServiceAssembly = initOptions.ConventionalServiceAssembly,
+                UseConventionalServiceAssembly = initOptions.UseConventionalServiceAssembly,
                 MessageEndPoint = initOptions.MessageEndPoint ?? this.MessageEndPoint,
                 InitEndPoint = initOptions.InitEndPoint ?? this.InitEndPoint,
             };
@@ -64,40 +64,51 @@ public WorkerInitOptions MergeWith(WorkerInitOptions initOptions)
     /// </summary>
     public static class WorkerInitOptionsExtensions
     {
+
         /// <summary>
-        /// Deducts the name of the assembly containing the service using the  the service type assembly name + dll extension as file name, and adds it as a dependency.
+        /// Adds the specified assembly filesnames as dependencies
         /// </summary>
         /// <param name="source"></param>
+        /// <param name="dependentAssemblyFilenames"></param>
         /// <returns></returns>
-        public static WorkerInitOptions UseConventionalServiceAssembly(this WorkerInitOptions source)
+        public static WorkerInitOptions AddAssemblies(this WorkerInitOptions source, params string[] dependentAssemblyFilenames)
         {
-            source.ConventionalServiceAssembly = true;
+            source.DependentAssemblyFilenames =
+                source.DependentAssemblyFilenames.Concat(dependentAssemblyFilenames).ToArray();
             return source;
         }
 
         /// <summary>
-        /// Deducts the name of the assembly containing the specified type using the assembly name with dll extension as file name, and adds it as a dependency.
+        /// Deducts the name of the assembly containing the service using the the service type assembly name with dll extension as file name, and adds it as a dependency.
         /// </summary>
         /// <param name="source"></param>
         /// <returns></returns>
-        public static WorkerInitOptions AddConventionalDependencyFor<T>(this WorkerInitOptions source)
+        public static WorkerInitOptions AddConventionalAssemblyOfService(this WorkerInitOptions source)
         {
-            source.DependentAssemblyFilenames =
-                source.DependentAssemblyFilenames.Concat(new[] {$"{typeof(T).Assembly.GetName().Name}.dll" }).ToArray();
+            source.UseConventionalServiceAssembly = true;
+            return source;
+        }
+
+        /// <summary>
+        /// Deducts the name of the assembly containing the specified <typeparamref name="T"/> using the assembly name with dll extension as file name, and adds it as a dependency.
+        /// </summary>
+        /// <param name="source"></param>
+        /// <returns></returns>
+        public static WorkerInitOptions AddAssemblyOf<T>(this WorkerInitOptions source)
+        {
+            source.AddAssemblies($"{typeof(T).Assembly.GetName().Name}.dll");
             return source;
         }
 
         /// <summary>
-        /// Registers the neccessary dependencies for instanciating <see cref="System.Net.Http.HttpClient"/> in the background service.
+        /// Registers the neccessary dependencies for injecting or instanciating <see cref="System.Net.Http.HttpClient"/> in the background service.
         /// </summary>
         /// <param name="source"></param>
         /// <returns></returns>
+        /// <remarks>When this method has been called, <see cref="System.Net.Http.HttpClient"/> can be used inside the service either by instanciating it or by injection into the constructor.</remarks>
         public static WorkerInitOptions AddHttpClient(this WorkerInitOptions source)
         {
-            source.DependentAssemblyFilenames = 
-                source.DependentAssemblyFilenames.Concat(new[] {  
-                    "System.Net.Http.dll",
-                    "System.Net.Http.WebAssemblyHttpHandler.dll" }).ToArray();
+            source.AddAssemblies("System.Net.Http.dll", "System.Net.Http.WebAssemblyHttpHandler.dll");
             return source;
         }
     }

src/BlazorWorker.WorkerCore/InitOptions.cs

@@ -12,14 +12,24 @@ public class SimpleInstanceService
 
         public static readonly SimpleInstanceService Instance = new SimpleInstanceService();
         public readonly Dictionary<long, InstanceWrapper> instances = new Dictionary<long, InstanceWrapper>();
-
+        
         public static readonly string MessagePrefix = $"{typeof(SimpleInstanceService).FullName}::";
         public static readonly string InitServiceResultMessagePrefix = $"{nameof(InitServiceResult)}::";
         public static readonly string InitInstanceMessagePrefix = $"{nameof(InitInstance)}::";
         public static readonly string InitInstanceResultMessagePrefix = $"{nameof(InitInstanceResult)}::";
         public static readonly string DiposeMessagePrefix = $"{nameof(DisposeInstance)}::";
         public static readonly string DiposeResultMessagePrefix = $"{nameof(DisposeResult)}::";
 
+        private static Type _typeOfHttpClient;
+        private const string HttpClientFullName = "System.Net.Http.HttpClient, System.Net.Http";
+
+        // The type of HttpClient is lazy loaded as the image might not exist
+        private static Type TypeOfHttpClient() =>
+            _typeOfHttpClient ??= Type.GetType(HttpClientFullName, true);
+
+        private static object HttpClientFactory() =>
+            Activator.CreateInstance(TypeOfHttpClient());
+
         static SimpleInstanceService()
         {
             AppDomain.CurrentDomain.AssemblyResolve += LogFailedAssemblyResolve;
@@ -133,19 +143,37 @@ public DisposeResult DisposeInstance(DisposeInstanceRequest request)
             }   
         }
 
-        private class ServiceCollection: Dictionary<Type, Func<object>>
+        private class ServiceCollection : Dictionary<string, Func<object>>
         {
+
             public void Add<T>(Func<T> factory)
             {
-                this.Add(typeof(T), () => factory());
+                this.Add(GetQualifiedNameWithoutVersion(typeof(T)), () => factory());
+            }
+
+            internal bool ContainsKey(Type parameterType)
+            {
+                Console.WriteLine($"ContainsKey {GetQualifiedNameWithoutVersion(parameterType)}?");
+                Console.WriteLine($"Keys: {string.Join(';', this.Keys)}");
+                return this.ContainsKey(GetQualifiedNameWithoutVersion(parameterType));
+            }
+
+            internal Func<object> GetFactory(Type parameterType)
+            {
+                return this[GetQualifiedNameWithoutVersion(parameterType)];
+            }
+
+            private string GetQualifiedNameWithoutVersion(Type forType)
+            {
+                return $"{forType.FullName}, {forType.Assembly.GetName().Name}";
             }
         }
 
         private static InitInstanceResult InitInstance(long callId, string typeName, string assemblyName, Func<IWorkerMessageService> workerMessageServiceFactory)
         {
             var services = new ServiceCollection
             {
-                () => new HttpClient(),
+                { HttpClientFullName, HttpClientFactory },
                 workerMessageServiceFactory
             };
 
@@ -158,6 +186,7 @@ private static InitInstanceResult InitInstance(long callId, string typeName, str
                 foreach (var constructor in constructors)
                 {
                     var parameters = constructor.GetParameters();
+                    // Will favour the contructor with the highest count of supported arguments
                     if (lastMatchArgCount < parameters.Length)
                     {
                         if (parameters.All(parameter => services.ContainsKey(parameter.ParameterType)))
@@ -174,7 +203,7 @@ private static InitInstanceResult InitInstance(long callId, string typeName, str
                 }
 
                 // Create instances for each constructor argument matching a supported service.
-                var serviceInstances = constructorInfo.GetParameters().Select(parameter => services[parameter.ParameterType].Invoke()).ToArray();
+                var serviceInstances = constructorInfo.GetParameters().Select(parameter => services.GetFactory(parameter.ParameterType).Invoke()).ToArray();
 
                 var instance = constructorInfo.Invoke(serviceInstances);
 
@@ -198,10 +227,12 @@ private static InitInstanceResult InitInstance(long callId, string typeName, str
             }
         }
 
+
         private static Assembly LogFailedAssemblyResolve(object sender, ResolveEventArgs args)
         {
             Console.Error.WriteLine($"{typeof(SimpleInstanceService).FullName}: '{args.RequestingAssembly}' is requesting missing assembly '{args.Name}')");
 
+            //return null;
             // Nobody really cares about this exception for now, it can't be caught.
             throw new InvalidOperationException($"{typeof(SimpleInstanceService).FullName}: '{args.RequestingAssembly}' is requesting missing assembly '{args.Name}')");
         }