Created an Assertion for StatusCodeShouldBeSuccess (#161)

* Created an Assertion for StatusCodeShouldBeSuccess

* Rebase

---------

Co-authored-by: JT <Hawxy@users.noreply.github.com>

src/Alba.Testing/Acceptance/asserting_against_status_code.cs

@@ -69,5 +69,53 @@ public async Task happily_blows_up_on_an_unexpected_500()
             ex.Message.ShouldContain("Expected status code 200, but was 500");
             ex.Message.ShouldContain("the error text");
         }
+
+        [Fact]
+        public async Task using_scenario_with_StatusCodeShouldBeSuccess_happy_path()
+        {
+            router.Handlers["/one"] = c =>
+            {
+                c.Response.StatusCode = 204;
+                c.Response.ContentType("text/plain");
+                c.Response.Write("Some text");
+
+                return Task.CompletedTask;
+            };
+
+            var ex = await Exception<ScenarioAssertionException>.ShouldBeThrownBy(() =>
+            {
+                return host.Scenario(x =>
+                {
+                    x.Get.Url("/one");
+                    x.StatusCodeShouldBeSuccess();
+                });
+            });
+
+        }
+
+        [Fact]
+        public async Task using_scenario_with_StatusCodeShouldBeSuccess_sad_path()
+        {
+            router.Handlers["/one"] = c =>
+            {
+                c.Response.StatusCode = 500;
+                c.Response.ContentType("text/plain");
+                c.Response.Write("Some text");
+
+                return Task.CompletedTask;
+            };
+
+            var ex = await Exception<ScenarioAssertionException>.ShouldBeThrownBy(() =>
+            {
+                return host.Scenario(x =>
+                {
+                    x.Get.Url("/one");
+                    x.StatusCodeShouldBeSuccess();
+                });
+            });
+
+            ex.Message.ShouldContain("Expected status code 200, but was 500");
+        }
+
     }
 }

src/Alba.Testing/Assertions/StatusCodeSuccessAssertionTests.cs

@@ -0,0 +1,69 @@
+using Alba.Assertions;
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Alba.Testing.Assertions
+{
+    public class StatusCodeSuccessAssertionTests
+    {
+        [Theory]
+        [ClassData(typeof(SuccessStatusCodes))]
+        public void HappyPath(int statusCode)
+        {
+            var assertion = new StatusCodeSuccessAssertion();
+
+            AssertionRunner.Run(assertion, _ => _.StatusCode(statusCode))
+                .AssertAll();
+        }
+
+        [Theory]
+        [ClassData(typeof(FailureStatusCodes))]
+        public void SadPath(int statusCode)
+        {
+            var assertion = new StatusCodeSuccessAssertion();
+
+            AssertionRunner.Run(assertion, _ => _.StatusCode(statusCode))
+                .SingleMessageShouldBe($"Expected a status code between 200 and 299, but was {statusCode}");
+        }
+    }
+
+
+
+}
+
+public class SuccessStatusCodes : IEnumerable<object[]>
+{
+    public IEnumerator<object[]> GetEnumerator()
+    {
+        foreach (var code in Enumerable.Range(200, 99))
+        {
+            yield return new object[] { code };
+        }
+    }
+
+    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+
+}
+
+public class FailureStatusCodes : IEnumerable<object[]>
+{
+    public IEnumerator<object[]> GetEnumerator()
+    {
+        foreach (var code in Enumerable.Range(100, 99))
+        {
+            yield return new object[] { code };
+        }
+        foreach (var code in Enumerable.Range(300, 200))
+        {
+            yield return new object[] { code };
+        }
+    }
+
+    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+
+}

src/Alba/Assertions/StatusCodeSuccessAssertion.cs

@@ -0,0 +1,14 @@
+namespace Alba.Assertions;
+
+public sealed class StatusCodeSuccessAssertion : IScenarioAssertion
+{
+    public void Assert(Scenario scenario, AssertionContext context)
+    {
+        var statusCode = context.HttpContext.Response.StatusCode;
+        if(statusCode < 200 || statusCode >= 300)
+        {
+            context.AddFailure($"Expected a status code between 200 and 299, but was {statusCode}");
+            context.ReadBodyAsString();
+        }
+    }
+}

src/Alba/ScenarioExpectationsExtensions.cs

@@ -1,11 +1,12 @@
 using System.Net;
 using Alba.Assertions;
- 
+
 namespace Alba;
 
 public static class ScenarioExpectationsExtensions
 {
     #region sample_ContentShouldContain
+
     /// <summary>
     /// Assert that the Http response contains the designated text
     /// </summary>
@@ -16,6 +17,7 @@ public static Scenario ContentShouldContain(this Scenario scenario, string text)
     {
         return scenario.AssertThat(new BodyContainsAssertion(text));
     }
+
     #endregion
 
     /// <summary>
@@ -50,6 +52,16 @@ public static Scenario StatusCodeShouldBeOk(this Scenario scenario)
         return scenario.StatusCodeShouldBe(HttpStatusCode.OK);
     }
 
+    /// <summary>
+    /// Assert that the Http Status Code is between 200 and 299
+    /// </summary>
+    /// <param name="scenario"></param>
+    /// <returns></returns>
+    public static Scenario StatusCodeShouldBeSuccess(this Scenario scenario)
+    {
+        return scenario.AssertThat(new StatusCodeSuccessAssertion());
+    }
+
     /// <summary>
     /// Assert that the content-type header value of the Http response
     /// matches the expected value