WebAPISignalRChat/Backend/Tests/ExceptionHandlingMiddlewareTest.cs

using Diligent.WebAPI.Host.Exceptions;
using Diligent.WebAPI.Host.Middlewares;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Moq;
using System.Net;

namespace Tests
{
    [TestFixture]
    public class ExceptionHandlingMiddlewareTest
    {
        [SetUp]
        public void Setup()
        {

        }

        [Test]
        public async Task ExceptionHandlingMiddleware_Returns500StatusCode_WhenArgumentNullExceptionIsThrown()
        {
            //arrange
            var expectedException = new ArgumentNullException();
            RequestDelegate mockNext = (HttpContext) =>
            {
                return Task.FromException(expectedException);
            };
            var httpContext = new DefaultHttpContext();

            var logger = new Mock<ILogger<ExceptionHandlingMiddleware>>();

            var exceptionHandlingMiddleware = new ExceptionHandlingMiddleware(mockNext, logger.Object); ;

            //act
            await exceptionHandlingMiddleware.InvokeAsync(httpContext);

            //assert
            Assert.AreEqual(HttpStatusCode.InternalServerError, (HttpStatusCode)httpContext.Response.StatusCode);
        }

        [Test]
        public async Task ExceptionHandlingMiddleware_Returns404StatusCode_WhenNotFoundExceptionIsThrown()
        {
            //arrange
            var expectedException = new NotFoundException();
            RequestDelegate mockNext = (HttpContext) =>
            {
                return Task.FromException(expectedException);
            };
            var httpContext = new DefaultHttpContext();

            var logger = new Mock<ILogger<ExceptionHandlingMiddleware>>();

            var exceptionHandlingMiddleware = new ExceptionHandlingMiddleware(mockNext, logger.Object); ;

            //act
            await exceptionHandlingMiddleware.InvokeAsync(httpContext);

            //assert
            Assert.AreEqual(HttpStatusCode.NotFound, (HttpStatusCode)httpContext.Response.StatusCode);
        }

        [Test]
        public async Task ExceptionHandlingMiddleware_ReturnsOkStatusCode_WhenNoExceptionIsThrown()
        {
            //arrange
            var expectedException = new NotFoundException();
            
            RequestDelegate mockNextMiddleware = (HttpContext) =>
            {
                return Task.CompletedTask;
            };

            var httpContext = new DefaultHttpContext();
            var logger = new Mock<ILogger<ExceptionHandlingMiddleware>>();

            var exceptionHandlingMiddleware = new ExceptionHandlingMiddleware(mockNextMiddleware, logger.Object); ;

            //act
            await exceptionHandlingMiddleware.InvokeAsync(httpContext);

            //assert
            Assert.Less((HttpStatusCode)httpContext.Response.StatusCode, 300);
        }
    }

}