Fixes JasperFx#171

Author: Christian Bergum Bergersen

src/Alba.Testing/Assertions/BodyTextAssertionTests.cs

@@ -19,7 +19,7 @@ public void sad_path()
         {
             var assertion = new BodyTextAssertion("Hey!");
             AssertionRunner.Run(assertion, env => env.Response.Write("Hey! You!"))
-                .Messages.Single().ShouldContain("Expected the content to be 'Hey!'");
+                .Messages.Single().ShouldBe("Expected the content to be 'Hey!', but was 'Hey! You!'");
         }
     }
 }

src/Alba/Assertions/BodyTextAssertion.cs

@@ -1,5 +1,3 @@
-using Microsoft.AspNetCore.Http;
-
 namespace Alba.Assertions;
 
 internal sealed class BodyTextAssertion : IScenarioAssertion
@@ -16,7 +14,7 @@ public void Assert(Scenario scenario, AssertionContext context)
         var body = context.ReadBodyAsString();
         if (!body.Equals(Text))
         {
-            context.AddFailure($"Expected the content to be '{Text}'");
+            context.AddFailure($"Expected the content to be '{Text}', but was '{body}'");
         }
     }
 }