CustomHttpStatusCodeResultTests.cs

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Http.Features;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Primitives;
using System.Text.Json;

namespace Teapot.Web.Tests.UnitTests;

public class CustomHttpStatusCodeResultTests
{
    private HttpContext _httpContext;
    private HttpResponseFeature _httpResponseFeature;
    private Stream _body;

    [SetUp]
    public void Setup()
    {
        Mock<ILogger> logger = new();
        Mock<ILoggerFactory> loggerFactory = new();
        Mock<IServiceProvider> serviceProvider = new();
        loggerFactory.Setup(x => x.CreateLogger(It.IsAny<string>())).Returns(logger.Object);
        serviceProvider.Setup(x => x.GetService(typeof(ILogger))).Returns(logger.Object);
        serviceProvider.Setup(x => x.GetService(typeof(ILoggerFactory))).Returns(loggerFactory.Object);

        FeatureCollection featureCollection = new();
        _httpResponseFeature = new HttpResponseFeature();
        _body = new MemoryStream();
        featureCollection.Set<IHttpRequestFeature>(new HttpRequestFeature());
        featureCollection.Set<IHttpResponseFeature>(_httpResponseFeature);
        featureCollection.Set<IHttpResponseBodyFeature>(new StreamResponseBodyFeature(_body));

        _httpContext = new DefaultHttpContext(featureCollection)
        {
            RequestServices = serviceProvider.Object
        };
    }

    [TestCaseSource(typeof(TestCases), nameof(TestCases.StatusCodesAll))]
    public async Task Response_Is_Correct(TestCase testCase)
    {
        CustomHttpStatusCodeResult target = new(testCase.Code, testCase.TeapotStatusCodeMetadata, null, null, []);

        await target.ExecuteAsync(_httpContext);
        Assert.Multiple(() =>
        {
            Assert.That(_httpContext.Response.StatusCode, Is.EqualTo(testCase.Code));
            Assert.That(_httpContext.Response.ContentType, Is.EqualTo(testCase.TeapotStatusCodeMetadata.ExcludeBody ? null : "text/plain"));
            Assert.That(_httpResponseFeature.ReasonPhrase, Is.EqualTo(testCase.Description));
        });

        if (testCase.TeapotStatusCodeMetadata.ExcludeBody)
        {
            Assert.That(_httpContext.Response.ContentLength, Is.Null);
        }
        else
        {
            _body.Position = 0;
            StreamReader sr = new(_body);
            string body = sr.ReadToEnd();
            Assert.Multiple(() =>
            {
                Assert.That(body, Is.EqualTo(testCase.Body));
                Assert.That(_httpContext.Response.ContentLength, Is.EqualTo(body?.Length));
            });
        }
    }

    [TestCaseSource(typeof(TestCases), nameof(TestCases.StatusCodesAll))]
    public async Task Response_Json_Is_Correct(TestCase testCase)
    {
        CustomHttpStatusCodeResult target = new(testCase.Code, testCase.TeapotStatusCodeMetadata, null, null, []);

        _httpContext.Request.Headers.Accept = "application/json";

        await target.ExecuteAsync(_httpContext);
        Assert.Multiple(() =>
        {
            Assert.That(_httpContext.Response.StatusCode, Is.EqualTo(testCase.Code));
            Assert.That(_httpContext.Response.ContentType, Is.EqualTo(testCase.TeapotStatusCodeMetadata.ExcludeBody ? null : "application/json"));
            Assert.That(_httpResponseFeature.ReasonPhrase, Is.EqualTo(testCase.Description));
        });
        if (testCase.TeapotStatusCodeMetadata.ExcludeBody)
        {
            Assert.That(_httpContext.Response.ContentLength, Is.Null);
        }
        else
        {
            _body.Position = 0;
            StreamReader sr = new(_body);
            string body = sr.ReadToEnd();
            string expectedBody = JsonSerializer.Serialize(new { code = testCase.Code, description = testCase.TeapotStatusCodeMetadata.Body ?? testCase.TeapotStatusCodeMetadata.Description });
            Assert.Multiple(() =>
            {
                Assert.That(body, Is.EqualTo(expectedBody));
                Assert.That(_httpContext.Response.ContentLength, Is.EqualTo(body.Length));
            });
        }
    }

    [TestCaseSource(typeof(TestCases), nameof(TestCases.StatusCodesNoContent))]
    public async Task Response_No_Content(TestCase testCase)
    {
        _httpContext.Response.Headers.ContentType = "text/plain";
        _httpContext.Response.Headers["Content-Length"] = "42";

        CustomHttpStatusCodeResult target = new(testCase.Code, testCase.TeapotStatusCodeMetadata, null, null, []);

        await target.ExecuteAsync(_httpContext);
        Assert.Multiple(() =>
        {
            Assert.That(_httpContext.Response.StatusCode, Is.EqualTo(testCase.Code));
            Assert.That(_httpContext.Response.ContentType, Is.Null);
            Assert.That(_httpResponseFeature.ReasonPhrase, Is.EqualTo(testCase.Description));
        });
        _body.Position = 0;
        StreamReader sr = new(_body);
        string body = sr.ReadToEnd();
        Assert.Multiple(() =>
        {
            Assert.That(body, Is.Empty);
            Assert.That(_httpContext.Response.ContentLength, Is.Null);
        });
    }

    [TestCaseSource(typeof(TestCases), nameof(TestCases.StatusCodesWithRetryAfter))]
    public async Task Response_Retry_After_Single_Header(TestCase testCase)
    {
        Dictionary<string, StringValues> customHeaders = new() {
            { "Retry-After", new StringValues("42") }
        };

        CustomHttpStatusCodeResult target = new(testCase.Code, testCase.TeapotStatusCodeMetadata, sleep: null, suppressBody: null, customHeaders);
        await target.ExecuteAsync(_httpContext);
        Assert.That(_httpContext.Response.Headers.RetryAfter, Has.Count.EqualTo(1));
    }
}