Made all tests pass

Had to use Moq framework to simplify the creation of the TempDataCollection. Was nearly impossible to test without that.

Author: Gimly

src/FluentAssertions.AspNetCore.Mvc/PartialViewResultAssertions.cs

@@ -111,7 +111,7 @@ public PartialViewResultAssertions WithTempData(string key, object expectedValue
         /// <returns>The typed model.</returns>
         public TModel ModelAs<TModel>()
         {
-            var model = PartialViewResultSubject.ViewData.Model;
+            var model = PartialViewResultSubject.ViewData?.Model;
 
             if (model == null)
                 Execute.Assertion.FailWith(FailureMessages.ViewResultBase_NullModel, typeof(TModel).Name);

tests/FluentAssertions.AspNetCore.Mvc.Tests/TestController.cs

@@ -10,9 +10,12 @@ namespace FluentAssertions.Mvc.Tests
 {
     public class TestController : Controller
     {
+        private Mock<ITempDataDictionary> _mockTempDataDictionary;
+
         public TestController()
         {
-            TempData = new Mock<ITempDataDictionary>().Object;
+            _mockTempDataDictionary = new Mock<ITempDataDictionary>();
+            TempData = _mockTempDataDictionary.Object;
         }
 
         public PartialViewResult PartialViewSimpleModel()
@@ -27,14 +30,22 @@ public ViewResult ViewSimpleModel()
 
         public ViewResult ViewWithOneTempData()
         {
-            TempData.Add("key1", "value1");
+            var mock = new Mock<ITempDataDictionary>();
+            mock.Setup(t => t.ContainsKey("key1")).Returns(true);
+            mock.Setup(t => t["key1"]).Returns("value1");
+            TempData = mock.Object;
             return View();
         }
 
         public ViewResult ViewWithTwoTempData()
         {
-            TempData.Add("key1", "value1");
-            TempData.Add("key2", "value2");
+            var mock = new Mock<ITempDataDictionary>();
+            mock.Setup(t => t.ContainsKey("key1")).Returns(true);
+            mock.Setup(t => t.ContainsKey("key2")).Returns(true);
+            mock.Setup(t => t["key1"]).Returns("value1");
+            mock.Setup(t => t["key2"]).Returns("value2");
+
+            TempData = mock.Object;
             return View();
         }
 

tests/FluentAssertions.Mvc.Tests.Shared/PartialViewResultAssertions_Tests.cs

@@ -104,7 +104,10 @@ public void ModelAs_Null_ShouldFail()
             ActionResult result = new PartialViewResult();
             string failureMessage = FailureMessageHelper.Format(FailureMessages.ViewResultBase_NullModel, typeof(Object).Name);
 
-            Action a = () => result.Should().BePartialViewResult().ModelAs<Object>();
+            Action a = () =>
+            {
+                result.Should().BePartialViewResult().ModelAs<Object>();
+            };
 
             a.ShouldThrow<Exception>()
                     .WithMessage(failureMessage);