Add comprehensive test coverage for course creation feature

api/CourseRegistration.API.Tests/Controllers/CoursesControllerIntegrationTests.cs

@@ -0,0 +1,117 @@
+using System.Net;
+using System.Net.Http.Json;
+using System.Text.Json;
+using CourseRegistration.Application.DTOs;
+using FluentAssertions;
+using Microsoft.AspNetCore.Mvc.Testing;
+using Xunit;
+
+namespace CourseRegistration.API.Tests.Controllers;
+
+/// <summary>
+/// Integration tests for CoursesController focusing on CreateCourse endpoint
+/// </summary>
+public class CoursesControllerIntegrationTests : IClassFixture<WebApplicationFactory<Program>>
+{
+    private readonly WebApplicationFactory<Program> _factory;
+    private readonly HttpClient _client;
+
+    public CoursesControllerIntegrationTests(WebApplicationFactory<Program> factory)
+    {
+        _factory = factory;
+        _client = factory.CreateClient();
+    }
+
+    [Fact]
+    public async Task CreateCourse_WithValidData_ShouldReturn201Created()
+    {
+        // Arrange
+        var createCourseDto = new CreateCourseDto
+        {
+            CourseName = "Integration Test Course",
+            Description = "This is a test course created during integration testing",
+            InstructorName = "Dr. Test",
+            StartDate = DateTime.UtcNow.AddDays(30),
+            EndDate = DateTime.UtcNow.AddDays(60),
+            Schedule = "MWF 10:00-11:30"
+        };
+
+        // Act
+        var response = await _client.PostAsJsonAsync("/api/courses", createCourseDto);
+
+        // Assert
+        response.StatusCode.Should().Be(HttpStatusCode.Created);
+
+        var content = await response.Content.ReadAsStringAsync();
+        content.Should().NotBeNullOrEmpty();
+
+        var apiResponse = JsonSerializer.Deserialize<JsonElement>(content);
+        apiResponse.GetProperty("success").GetBoolean().Should().BeTrue();
+        apiResponse.GetProperty("data").GetProperty("courseName").GetString().Should().Be(createCourseDto.CourseName);
+    }
+
+    [Fact]
+    public async Task CreateCourse_WithStartDateInPast_ShouldReturn400BadRequest()
+    {
+        // Arrange
+        var createCourseDto = new CreateCourseDto
+        {
+            CourseName = "Invalid Course",
+            Description = "Course with past start date",
+            InstructorName = "Dr. Test",
+            StartDate = DateTime.UtcNow.AddDays(-5),
+            EndDate = DateTime.UtcNow.AddDays(30),
+            Schedule = "MWF 10:00-11:30"
+        };
+
+        // Act
+        var response = await _client.PostAsJsonAsync("/api/courses", createCourseDto);
+
+        // Assert
+        response.StatusCode.Should().Be(HttpStatusCode.BadRequest);
+    }
+
+    [Fact]
+    public async Task CreateCourse_WithEndDateBeforeStartDate_ShouldReturn400BadRequest()
+    {
+        // Arrange
+        var createCourseDto = new CreateCourseDto
+        {
+            CourseName = "Invalid Course",
+            Description = "Course with end date before start date",
+            InstructorName = "Dr. Test",
+            StartDate = DateTime.UtcNow.AddDays(60),
+            EndDate = DateTime.UtcNow.AddDays(30),
+            Schedule = "MWF 10:00-11:30"
+        };
+
+        // Act
+        var response = await _client.PostAsJsonAsync("/api/courses", createCourseDto);
+
+        // Assert
+        response.StatusCode.Should().Be(HttpStatusCode.BadRequest);
+    }
+
+    [Fact]
+    public async Task CreateCourse_ShouldReturnLocationHeader()
+    {
+        // Arrange
+        var createCourseDto = new CreateCourseDto
+        {
+            CourseName = "Location Header Test Course",
+            Description = "Testing location header",
+            InstructorName = "Dr. Location",
+            StartDate = DateTime.UtcNow.AddDays(30),
+            EndDate = DateTime.UtcNow.AddDays(60),
+            Schedule = "MWF 09:00-10:30"
+        };
+
+        // Act
+        var response = await _client.PostAsJsonAsync("/api/courses", createCourseDto);
+
+        // Assert
+        response.StatusCode.Should().Be(HttpStatusCode.Created);
+        response.Headers.Location.Should().NotBeNull();
+        response.Headers.Location!.ToString().Should().Contain("/api/Courses/");
+    }
+}

api/CourseRegistration.API.Tests/CourseRegistration.API.Tests.csproj

@@ -0,0 +1,30 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="6.0.4" />
+    <PackageReference Include="FluentAssertions" Version="8.8.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="10.0.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageReference Include="Moq" Version="4.20.72" />
+    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.4" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\CourseRegistration.API\CourseRegistration.API.csproj" />
+    <ProjectReference Include="..\CourseRegistration.Application\CourseRegistration.Application.csproj" />
+    <ProjectReference Include="..\CourseRegistration.Domain\CourseRegistration.Domain.csproj" />
+  </ItemGroup>
+
+</Project>

api/CourseRegistration.API/Program.cs

@@ -299,3 +299,6 @@ static async Task SeedDatabase(CourseRegistrationDbContext context)
     Log.Information("Database seeded successfully with {StudentCount} students, {CourseCount} courses, and {RegistrationCount} registrations.", 
         students.Length, courses.Length, registrations.Length);
 }
+
+// Make Program accessible for integration tests
+public partial class Program { }

api/CourseRegistration.Application.Tests/CourseRegistration.Application.Tests.csproj

@@ -0,0 +1,29 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="AutoMapper" Version="15.1.0" />
+    <PackageReference Include="coverlet.collector" Version="6.0.4" />
+    <PackageReference Include="FluentAssertions" Version="8.8.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageReference Include="Moq" Version="4.20.72" />
+    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.4" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\CourseRegistration.Application\CourseRegistration.Application.csproj" />
+    <ProjectReference Include="..\CourseRegistration.Domain\CourseRegistration.Domain.csproj" />
+  </ItemGroup>
+
+</Project>