Merge pull request #372 from grumpydev/ErrorHandlersCollection

Swithed error handler to be a collection

Author: thecodejunkie

Diff for: src/Nancy.Demo.Hosting.Aspnet/CustomErrorHandler.cs

@@ -0,0 +1,27 @@
+namespace Nancy.Demo.Hosting.Aspnet
+{
+    using Nancy.ErrorHandling;
+
+    public class CustomErrorHandler : IErrorHandler
+    {
+        /// <summary>
+        /// Whether then 
+        /// </summary>
+        /// <param name="statusCode">Status code</param>
+        /// <returns>True if handled, false otherwise</returns>
+        public bool HandlesStatusCode(HttpStatusCode statusCode)
+        {
+            return statusCode == HttpStatusCode.ImATeapot;
+        }
+
+        /// <summary>
+        /// Handle the error code
+        /// </summary>
+        /// <param name="statusCode">Status code</param>
+        /// <param name="context">Current context</param>
+        public void Handle(HttpStatusCode statusCode, NancyContext context)
+        {
+            context.Response = "Response generated by a custom error handler";
+        }
+    }
+}

Diff for: src/Nancy.Demo.Hosting.Aspnet/MainModule.cs

@@ -129,6 +129,8 @@ public MainModule(IRouteCacheProvider routeCacheProvider)
                     throw new NotSupportedException("This is an exception thrown in a route.");
                 };
 
+            Get["/customErrorHandler"] = _ => HttpStatusCode.ImATeapot;
+
             Get["/csrf"] = x => this.View["csrf", new { Blurb = "CSRF without an expiry using the 'session' token" }];
 
             Post["/csrf"] = x =>

Diff for: src/Nancy.Demo.Hosting.Aspnet/Nancy.Demo.Hosting.Aspnet.csproj

@@ -117,6 +117,7 @@
       <Link>Properties\SharedAssemblyInfo.cs</Link>
     </Compile>
     <Compile Include="ApplicationDependencyClass.cs" />
+    <Compile Include="CustomErrorHandler.cs" />
     <Compile Include="HereBeAResponseYouScurvyDog.cs" />
     <Compile Include="DemoBootstrapper.cs" />
     <Compile Include="DependencyModule.cs" />

Diff for: src/Nancy.Testing/ConfigurableBootstrapper.cs

@@ -504,12 +504,11 @@ public ConfigurableBoostrapperConfigurator DisableAutoRegistration()
             /// <summary>
             /// Configures the bootstrapper to use the provided instance of <see cref="IErrorHandler"/>.
             /// </summary>
-            /// <param name="errorHandler">The <see cref="IErrorHandler"/> instance that should be used by the bootstrapper.</param>
+            /// <param name="errorHandlers">The <see cref="IErrorHandler"/> types that should be used by the bootstrapper.</param>
             /// <returns>A reference to the current <see cref="ConfigurableBoostrapperConfigurator"/>.</returns>
-            public ConfigurableBoostrapperConfigurator ErrorHandler(IErrorHandler errorHandler)
+            public ConfigurableBoostrapperConfigurator ErrorHandlers(params Type[] errorHandlers)
             {
-                this.bootstrapper.registeredInstances.Add(
-                    new InstanceRegistration(typeof(IErrorHandler), errorHandler));
+                this.bootstrapper.configuration.ErrorHandlers = new List<Type>(errorHandlers);
 
                 return this;
             }
@@ -521,7 +520,7 @@ public ConfigurableBoostrapperConfigurator ErrorHandler(IErrorHandler errorHandl
             /// <returns>A reference to the current <see cref="ConfigurableBoostrapperConfigurator"/>.</returns>
             public ConfigurableBoostrapperConfigurator ErrorHandler<T>() where T : IErrorHandler
             {
-                this.bootstrapper.configuration.ErrorHandler = typeof(T);
+                this.bootstrapper.configuration.ErrorHandlers = new List<Type>( new[] { typeof(T) } );
                 return this;
             }
 

Diff for: src/Nancy.Tests/Unit/NancyEngineFixture.cs

@@ -40,7 +40,7 @@ public NancyEngineFixture()
             var applicationPipelines = new Pipelines();
 
             this.engine = 
-                new NancyEngine(resolver, A.Fake<IRouteCache>(), contextFactory, this.errorHandler)
+                new NancyEngine(resolver, A.Fake<IRouteCache>(), contextFactory, new IErrorHandler[] { this.errorHandler })
                 {
                     RequestPipelinesFactory = ctx => applicationPipelines
                 };
@@ -51,7 +51,7 @@ public void Should_throw_argumentnullexception_when_created_with_null_resolver()
         {
             // Given, When
             var exception =
-                Record.Exception(() => new NancyEngine(null, A.Fake<IRouteCache>(), A.Fake<INancyContextFactory>(), this.errorHandler));
+                Record.Exception(() => new NancyEngine(null, A.Fake<IRouteCache>(), A.Fake<INancyContextFactory>(), new IErrorHandler[] { this.errorHandler }));
 
             // Then
             exception.ShouldBeOfType<ArgumentNullException>();
@@ -62,7 +62,7 @@ public void Should_throw_argumentnullexception_when_created_with_null_routecache
         {
             // Given, When
             var exception =
-                Record.Exception(() => new NancyEngine(A.Fake<IRouteResolver>(), null, A.Fake<INancyContextFactory>(), this.errorHandler));
+                Record.Exception(() => new NancyEngine(A.Fake<IRouteResolver>(), null, A.Fake<INancyContextFactory>(), new IErrorHandler[] { this.errorHandler }));
 
             // Then
             exception.ShouldBeOfType<ArgumentNullException>();
@@ -73,7 +73,7 @@ public void Should_throw_argumentnullexception_when_created_with_null_context_fa
         {
             // Given, When
             var exception =
-                Record.Exception(() => new NancyEngine(A.Fake<IRouteResolver>(), A.Fake<IRouteCache>(), null, this.errorHandler));
+                Record.Exception(() => new NancyEngine(A.Fake<IRouteResolver>(), A.Fake<IRouteCache>(), null, new IErrorHandler[] { this.errorHandler }));
 
             // Then
             exception.ShouldBeOfType<ArgumentNullException>();
@@ -159,7 +159,7 @@ public void Should_not_throw_exception_when_setting_nancy_version_header_and_it_
             var pipelines = new Pipelines();
 
             var localEngine =
-                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, this.errorHandler)
+                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, new IErrorHandler[] { this.errorHandler })
                 {
                     RequestPipelinesFactory = ctx => pipelines
                 };
@@ -315,7 +315,7 @@ public void HandleRequest_should_call_route_prereq_then_invoke_route_then_call_r
             var pipelines = new Pipelines();
 
             var localEngine =
-                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, this.errorHandler)
+                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, new IErrorHandler[] { this.errorHandler })
                 {
                     RequestPipelinesFactory = ctx => pipelines
                 };
@@ -343,7 +343,7 @@ public void HandleRequest_should_not_invoke_route_if_route_prereq_returns_respon
             var pipelines = new Pipelines();
 
             var localEngine =
-                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, this.errorHandler)
+                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, new IErrorHandler[] { this.errorHandler })
                 {
                     RequestPipelinesFactory = ctx => pipelines
                 };
@@ -366,7 +366,7 @@ public void HandleRequest_should_return_response_from_route_prereq_if_one_return
             var pipelines = new Pipelines();
 
             var localEngine =
-                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, this.errorHandler)
+                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, new IErrorHandler[] { this.errorHandler })
                 {
                     RequestPipelinesFactory = ctx => pipelines
                 };
@@ -389,7 +389,7 @@ public void HandleRequest_should_allow_route_postreq_to_change_response()
             var pipelines = new Pipelines();
 
             var localEngine =
-                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, this.errorHandler)
+                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, new IErrorHandler[] { this.errorHandler })
                 {
                     RequestPipelinesFactory = ctx => pipelines
                 };
@@ -411,7 +411,7 @@ public void HandleRequest_should_allow_route_postreq_to_add_items_to_context()
             var pipelines = new Pipelines();
 
             var localEngine =
-                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, this.errorHandler)
+                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, new IErrorHandler[] { this.errorHandler })
                 {
                     RequestPipelinesFactory = ctx => pipelines
                 };
@@ -460,7 +460,7 @@ public void HandleRequest_route_prereq_returns_response_should_still_run_route_p
             pipelines.AfterRequest.AddItemToStartOfPipeline(postHook);
 
             var localEngine =
-                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, this.errorHandler)
+                new NancyEngine(prePostResolver, A.Fake<IRouteCache>(), contextFactory, new IErrorHandler[] { this.errorHandler })
                 {
                     RequestPipelinesFactory = ctx => pipelines
                 };

Diff for: src/Nancy/Bootstrapper/NancyInternalConfiguration.cs

@@ -47,7 +47,7 @@ public static NancyInternalConfiguration Default
                         RenderContextFactory = typeof(DefaultRenderContextFactory),
                         ViewLocationCache = typeof(DefaultViewLocationCache),
                         ViewLocationProvider = typeof(FileSystemViewLocationProvider),
-                        ErrorHandler = typeof(DefaultErrorHandler),
+                        ErrorHandlers = new List<Type>(new[] { typeof(DefaultErrorHandler) }.Concat(AppDomainAssemblyTypeScanner.TypesOf<IErrorHandler>(true))),
                         CsrfTokenValidator = typeof(DefaultCsrfTokenValidator),
                         ObjectSerializer = typeof(DefaultObjectSerializer),
                         Serializers = new List<Type>(new[] { typeof(DefaultJsonSerializer), typeof(DefaultXmlSerializer) }),
@@ -95,7 +95,7 @@ public static NancyInternalConfiguration Default
 
         public Type ViewLocationProvider { get; set; }
 
-        public Type ErrorHandler { get; set; }
+        public IList<Type> ErrorHandlers { get; set; }
 
         public Type CsrfTokenValidator { get; set; }
 
@@ -163,7 +163,6 @@ public IEnumerable<TypeRegistration> GetTypeRegistations()
                 new TypeRegistration(typeof(IRenderContextFactory), this.RenderContextFactory),
                 new TypeRegistration(typeof(IViewLocationCache), this.ViewLocationCache),
                 new TypeRegistration(typeof(IViewLocationProvider), this.ViewLocationProvider),
-                new TypeRegistration(typeof(IErrorHandler), this.ErrorHandler), 
                 new TypeRegistration(typeof(ICsrfTokenValidator), this.CsrfTokenValidator), 
                 new TypeRegistration(typeof(IObjectSerializer), this.ObjectSerializer), 
             };
@@ -178,6 +177,7 @@ public IEnumerable<CollectionTypeRegistration> GetCollectionTypeRegistrations()
             return new[]
             {
                 new CollectionTypeRegistration(typeof(ISerializer), this.Serializers), 
+                new CollectionTypeRegistration(typeof(IErrorHandler), this.ErrorHandlers), 
             };
         }
     }

Diff for: src/Nancy/NancyEngine.cs

@@ -1,6 +1,8 @@
 namespace Nancy
 {
     using System;
+    using System.Collections.Generic;
+    using System.Linq;
     using System.Threading;
     using Bootstrapper;
     using Nancy.ErrorHandling;
@@ -16,16 +18,16 @@ public class NancyEngine : INancyEngine
         private readonly IRouteResolver resolver;
         private readonly IRouteCache routeCache;
         private readonly INancyContextFactory contextFactory;
-        private readonly IErrorHandler errorHandler;
+        private readonly IEnumerable<IErrorHandler> errorHandlers;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="NancyEngine"/> class.
         /// </summary>
         /// <param name="resolver">An <see cref="IRouteResolver"/> instance that will be used to resolve a route, from the modules, that matches the incoming <see cref="Request"/>.</param>
         /// <param name="routeCache">Cache of all available routes</param>
         /// <param name="contextFactory">A factory for creating contexts</param>
-        /// <param name="errorHandler">Error handler</param>
-        public NancyEngine(IRouteResolver resolver, IRouteCache routeCache, INancyContextFactory contextFactory, IErrorHandler errorHandler)
+        /// <param name="errorHandlers">Error handlers</param>
+        public NancyEngine(IRouteResolver resolver, IRouteCache routeCache, INancyContextFactory contextFactory, IEnumerable<IErrorHandler> errorHandlers)
         {
             if (resolver == null)
             {
@@ -42,15 +44,15 @@ public NancyEngine(IRouteResolver resolver, IRouteCache routeCache, INancyContex
                 throw new ArgumentNullException("contextFactory");
             }
 
-            if (errorHandler == null)
+            if (errorHandlers == null)
             {
-                throw new ArgumentNullException("errorHandler");
+                throw new ArgumentNullException("errorHandlers");
             }
 
             this.resolver = resolver;
             this.routeCache = routeCache;
             this.contextFactory = contextFactory;
-            this.errorHandler = errorHandler;
+            this.errorHandlers = errorHandlers;
         }
 
         /// <summary>
@@ -129,9 +131,9 @@ private void CheckErrorHandler(NancyContext context)
                 return;
             }
 
-            if (this.errorHandler.HandlesStatusCode(context.Response.StatusCode))
+            foreach (var errorHandler in this.errorHandlers.Where(e => e.HandlesStatusCode(context.Response.StatusCode)))
             {
-                this.errorHandler.Handle(context.Response.StatusCode, context);
+                errorHandler.Handle(context.Response.StatusCode, context);
             }
         }