Task<ActionResult<T> action result is now resolved correctly (closes #370)

Author: ivaylokenov

samples/Blog/Blog.Web/Startup.cs

@@ -5,7 +5,6 @@
     using Data;
     using Data.Models;
     using Infrastructure;
-    using Services;
     using Microsoft.AspNetCore.Builder;
     using Microsoft.AspNetCore.Hosting;
     using Microsoft.AspNetCore.Http;
@@ -15,14 +14,15 @@
     using Microsoft.Extensions.Configuration;
     using Microsoft.Extensions.DependencyInjection;
     using Microsoft.Extensions.Hosting;
+    using Services;
 
     public class Startup
     {
         public Startup(IConfiguration configuration)
             => this.Configuration = configuration;
 
         public IConfiguration Configuration { get; }
-        
+
         public void ConfigureServices(IServiceCollection services)
         {
             services
@@ -67,7 +67,7 @@ public void ConfigureServices(IServiceCollection services)
 
             services.AddRazorPages();
         }
-        
+
         public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
         {
             if (env.IsDevelopment())

src/MyTested.AspNetCore.Mvc.Abstractions/Utilities/Extensions/ActionTestContextExtensions.cs

@@ -1,6 +1,7 @@
 namespace MyTested.AspNetCore.Mvc.Utilities.Extensions
 {
     using System;
+    using System.Threading.Tasks;
     using Internal.TestContexts;
     using Microsoft.AspNetCore.Mvc;
 
@@ -13,7 +14,8 @@ public static ActionTestContext ConvertMethodResult(this ActionTestContext testC
         {
             var methodReturnType = testContext.Method.ReturnType;
 
-            if (Reflection.AreAssignableByGeneric(ActionResultGenericType, methodReturnType))
+            if (Reflection.AreAssignableByGeneric(ActionResultGenericType, methodReturnType)
+                || Reflection.AreAssignableByTaskGeneric(ActionResultGenericType, methodReturnType))
             {
                 var methodResultType = testContext.MethodResult.GetType();
 

src/MyTested.AspNetCore.Mvc.Abstractions/Utilities/Reflection.cs

@@ -8,6 +8,7 @@
     using System.Linq.Expressions;
     using System.Reflection;
     using System.Runtime.CompilerServices;
+    using System.Threading.Tasks;
     using Extensions;
     using Internal;
     using Microsoft.AspNetCore.Routing;
@@ -122,6 +123,24 @@ public static bool AreAssignableByGeneric(Type baseType, Type inheritedType)
                 && IsGeneric(baseType) 
                 && baseType.IsAssignableFrom(inheritedType.GetGenericTypeDefinition());
 
+        /// <summary>
+        /// Checks whether two types are assignable by generic task definition.
+        /// </summary>
+        /// <param name="baseTaskType">Base type to be checked.</param>
+        /// <param name="inheritedTaskType">Inherited type to be checked.</param>
+        /// <returns>True or false.</returns>
+        public static bool AreAssignableByTaskGeneric(Type baseTaskType, Type inheritedTaskType)
+        {
+            if (!AreAssignableByGeneric(typeof(Task<>), inheritedTaskType))
+            {
+                return false;
+            }
+
+            var inheritedGenericArgument = inheritedTaskType.GetGenericArguments().First();
+
+            return AreAssignableByGeneric(baseTaskType, inheritedGenericArgument);
+        }
+
         /// <summary>
         /// Checks whether two generic types have different generic arguments.
         /// </summary>

src/MyTested.AspNetCore.Mvc.Abstractions/Utilities/Validators/InvocationResultValidator.cs

@@ -52,6 +52,7 @@ public static void ValidateInvocationResultTypes(
             ComponentTestContext testContext,
             bool canBeAssignable = false,
             bool allowDifferentGenericTypeDefinitions = false,
+            Type typeOfActualReturnValue = null,
             params Type[] typesOfExpectedReturnValue)
         {
             var invalid = false;
@@ -62,7 +63,8 @@ public static void ValidateInvocationResultTypes(
                     testContext,
                     type,
                     canBeAssignable,
-                    allowDifferentGenericTypeDefinitions);
+                    allowDifferentGenericTypeDefinitions,
+                    typeOfActualReturnValue);
 
                 if (!invalid)
                 {
@@ -76,7 +78,8 @@ public static void ValidateInvocationResultTypes(
                     " or ", 
                     typesOfExpectedReturnValue.Select(t => t.ToFriendlyTypeName()));
 
-                var actualTypeName = testContext.MethodResult?.GetType().ToFriendlyTypeName();
+                var actualTypeName = typeOfActualReturnValue?.ToFriendlyTypeName() 
+                    ?? testContext.MethodResult?.GetType().ToFriendlyTypeName();
 
                 ThrowNewInvocationResultAssertionException(
                     testContext,

src/MyTested.AspNetCore.Mvc.Controllers/Builders/ActionResults/ActionResult/ActionResultOfTTestBuilder.cs

@@ -20,10 +20,8 @@ public class ActionResultOfTTestBuilder<TResult>
         /// <see cref="ControllerTestContext"/> containing data about the currently executed assertion chain.
         /// </param>
         public ActionResultOfTTestBuilder(ControllerTestContext testContext) 
-            : base(testContext)
-        {
-            testContext.ConvertMethodResult();
-        }
+            : base(testContext) 
+            => testContext.ConvertMethodResult();
 
         /// <inheritdoc />
         public IActionResultOfTTestBuilder<TResult> AndAlso() => this;

src/MyTested.AspNetCore.Mvc.Controllers/Builders/Actions/ShouldReturn/ShouldReturnActionResultTestBuilder.cs

@@ -1,6 +1,7 @@
 namespace MyTested.AspNetCore.Mvc.Builders.Actions.ShouldReturn
 {
     using System;
+    using System.Threading.Tasks;
     using ActionResults.ActionResult;
     using And;
     using Contracts.ActionResults.ActionResult;
@@ -84,8 +85,13 @@ private void ValidateActionResults()
                 typesOfExpectedReturnValue: new[] { ActionResultType, GenericActionResultType });
 
         private void ValidateActionResult<TResult>()
-            => InvocationResultValidator.ValidateInvocationResultType<ActionResult<TResult>>(
+            => InvocationResultValidator.ValidateInvocationResultTypes(
                 this.TestContext,
-                typeOfActualReturnValue: this.TestContext.Method.ReturnType);
+                typeOfActualReturnValue: this.TestContext.Method.ReturnType,
+                typesOfExpectedReturnValue: new[]
+                {
+                    typeof(ActionResult<TResult>), 
+                    typeof(Task<ActionResult<TResult>>)
+                });
     }
 }

test/MyTested.AspNetCore.Mvc.Controllers.ActionResults.Test/BuildersTests/ActionResultsTests/ActionResultTests/ActionResultOfTTestBuilderTests.cs

@@ -42,5 +42,40 @@ public void ShouldReturnActionResultOfTWithDetailsShouldThrowExceptionWithIncorr
                 },
                 "When calling ActionResultOfT action in MvcController expected the response model to be the given model, but in fact it was a different one. Difference occurs at 'ResponseModel.IntegerValue'. Expected a value of '2', but in fact it was '1'.");
         }
+
+        [Fact]
+        public void ShouldReturnActionResultOfAsyncTWithDetailsShouldNotThrowExceptionWithEqualResult()
+        {
+            MyController<MvcController>
+                .Instance()
+                .Calling(c => c.ActionResultOfTAsync(1))
+                .ShouldReturn()
+                .ActionResult<ResponseModel>(result => result
+                    .EqualTo(new ResponseModel
+                    {
+                        IntegerValue = 1,
+                        StringValue = "Test"
+                    }));
+        }
+
+        [Fact]
+        public void ShouldReturnActionResultOfTAsyncWithDetailsShouldThrowExceptionWithIncorrectResult()
+        {
+            Test.AssertException<ResponseModelAssertionException>(
+                () =>
+                {
+                    MyController<MvcController>
+                        .Instance()
+                        .Calling(c => c.ActionResultOfTAsync(1))
+                        .ShouldReturn()
+                        .ActionResult<ResponseModel>(result => result
+                            .EqualTo(new ResponseModel
+                            {
+                                IntegerValue = 2,
+                                StringValue = "Test"
+                            }));
+                },
+                "When calling ActionResultOfTAsync action in MvcController expected the response model to be the given model, but in fact it was a different one. Difference occurs at 'ResponseModel.IntegerValue'. Expected a value of '2', but in fact it was '1'.");
+        }
     }
 }