From 9cec86b624f4327675e604d84864edbe91948e63 Mon Sep 17 00:00:00 2001
From: emantzoros <emantzoros94@gmail.com>
Date: Fri, 19 Sep 2025 22:20:09 +0300
Subject: [PATCH] Tests for exception handling middleware.

---
 .../Controllers/CustomerControllerTests.cs    |  1 +
 .../ErrorHandlingMiddlewareTests.cs           | 94 +++++++++++++++++++
 2 files changed, 95 insertions(+)
 create mode 100644 BlazorApp.Tests/Middlewares/ErrorHandlingMiddlewareTests.cs

diff --git a/BlazorApp.Tests/Controllers/CustomerControllerTests.cs b/BlazorApp.Tests/Controllers/CustomerControllerTests.cs
index 6419253..8f8a4cb 100644
--- a/BlazorApp.Tests/Controllers/CustomerControllerTests.cs
+++ b/BlazorApp.Tests/Controllers/CustomerControllerTests.cs
@@ -2,6 +2,7 @@ using BlazorApp.Controllers;
 using BlazorApp.Interfaces.Services;
 using BlazorApp.Shared.Models;
 using BlazorApp.Shared.Models.Pagination;
+using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
 using Moq;
 
diff --git a/BlazorApp.Tests/Middlewares/ErrorHandlingMiddlewareTests.cs b/BlazorApp.Tests/Middlewares/ErrorHandlingMiddlewareTests.cs
new file mode 100644
index 0000000..fd5537a
--- /dev/null
+++ b/BlazorApp.Tests/Middlewares/ErrorHandlingMiddlewareTests.cs
@@ -0,0 +1,94 @@
+using BlazorApp.Middlewares;
+using BlazorApp.Models.Exceptions;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Logging;
+using Moq;
+using System.Net;
+using System.Text;
+
+namespace BlazorApp.Tests.Middlewares
+{
+    public class ErrorHandlingMiddlewareTests
+    {
+        private readonly Mock<ILogger<ErrorHandlingMiddleware>> _loggerMock;
+
+        public ErrorHandlingMiddlewareTests()
+        {
+            _loggerMock = new Mock<ILogger<ErrorHandlingMiddleware>>();
+        }
+
+        private HttpContext CreateHttpContext()
+        {
+            var context = new DefaultHttpContext();
+            context.Response.Body = new MemoryStream();
+            return context;
+        }
+
+        private string GetResponseBody(HttpContext context)
+        {
+            context.Response.Body.Seek(0, SeekOrigin.Begin);
+            using var reader = new StreamReader(context.Response.Body, Encoding.UTF8);
+            return reader.ReadToEnd();
+        }
+
+        [Fact]
+        public async Task Invoke_WhenNotFoundException_Returns404()
+        {
+            var context = CreateHttpContext();
+            RequestDelegate next = (ctx) => throw new NotFoundException("blabla");
+
+            var middleware = new ErrorHandlingMiddleware(next, _loggerMock.Object);
+
+            await middleware.Invoke(context);
+
+            Assert.Equal((int)HttpStatusCode.NotFound, context.Response.StatusCode);
+            var body = GetResponseBody(context);
+            Assert.Contains("blabla", body);
+        }
+
+        [Fact]
+        public async Task Invoke_WhenBusinessException_Returns500()
+        {
+            var context = CreateHttpContext();
+            RequestDelegate next = (ctx) => throw new BusinessException("blabla");
+
+            var middleware = new ErrorHandlingMiddleware(next, _loggerMock.Object);
+
+            await middleware.Invoke(context);
+
+            Assert.Equal((int)HttpStatusCode.InternalServerError, context.Response.StatusCode);
+            var body = GetResponseBody(context);
+            Assert.Contains("blabla", body);
+        }
+
+        [Fact]
+        public async Task Invoke_WhenValidationException_Returns400()
+        {
+            var context = CreateHttpContext();
+            RequestDelegate next = (ctx) => throw new ValidationException("blabla");
+
+            var middleware = new ErrorHandlingMiddleware(next, _loggerMock.Object);
+
+            await middleware.Invoke(context);
+
+            Assert.Equal((int)HttpStatusCode.BadRequest, context.Response.StatusCode);
+            var body = GetResponseBody(context);
+            Assert.Contains("blabla", body);
+        }
+
+        [Fact]
+        public async Task Invoke_WhenUnhandledException_Returns500()
+        {
+            var context = CreateHttpContext();
+            RequestDelegate next = (ctx) => throw new Exception("blabla");
+
+            var middleware = new ErrorHandlingMiddleware(next, _loggerMock.Object);
+
+            await middleware.Invoke(context);
+
+            Assert.Equal((int)HttpStatusCode.InternalServerError, context.Response.StatusCode);
+            var body = GetResponseBody(context);
+            Assert.Contains("blabla", body);
+        }
+    }
+}