Add shared list products integration test with Theory-based pagination testing

01-VerticalSlice/src/OrderDemo.Api/Program.cs

@@ -71,3 +71,6 @@
 
 app.MapDefaultEndpoints(); // Important for Aspire health checks
 app.Run();
+
+// Make the implicit Program class public for integration tests
+public partial class Program { }

02-CleanArchitecture/tests/OrderDemo.CleanArch.IntegrationTests/Products/ListProductsIntegrationTests.cs

@@ -0,0 +1,110 @@
+using OrderDemo.CleanArch.Core.ProductAggregate;
+using OrderDemo.CleanArch.Infrastructure.Data;
+using OrderDemo.CleanArch.Infrastructure.Data.Queries;
+
+namespace OrderDemo.CleanArch.IntegrationTests.Products;
+
+public class ListProductsIntegrationTests
+{
+  private static DbContextOptions<AppDbContext> CreateNewContextOptions()
+  {
+    var fakeEventDispatcher = Substitute.For<IDomainEventDispatcher>();
+    var serviceProvider = new ServiceCollection()
+        .AddEntityFrameworkInMemoryDatabase()
+        .AddScoped<IDomainEventDispatcher>(_ => fakeEventDispatcher)
+        .AddScoped<EventDispatchInterceptor>()
+        .BuildServiceProvider();
+
+    var interceptor = serviceProvider.GetRequiredService<EventDispatchInterceptor>();
+
+    var builder = new DbContextOptionsBuilder<AppDbContext>();
+    builder.UseInMemoryDatabase($"listproductstest-{Guid.NewGuid()}")
+           .UseInternalServiceProvider(serviceProvider)
+           .AddInterceptors(interceptor);
+
+    return builder.Options;
+  }
+
+  private static async Task SeedTestProducts(AppDbContext dbContext, int count = 10)
+  {
+    for (int i = 1; i <= count; i++)
+    {
+      var product = new Product(ProductId.From(0), $"Product {i}", 10m + i);
+      dbContext.Products.Add(product);
+    }
+    await dbContext.SaveChangesAsync();
+  }
+
+  [Theory]
+  [InlineData(1, 5, 5, 10, 2)]  // page 1, pageSize 5, expectedItems 5, totalCount 10, totalPages 2
+  [InlineData(2, 5, 5, 10, 2)]  // page 2, pageSize 5, expectedItems 5, totalCount 10, totalPages 2
+  [InlineData(1, 10, 10, 10, 1)] // page 1, pageSize 10, expectedItems 10, totalCount 10, totalPages 1
+  [InlineData(1, 3, 3, 10, 4)]  // page 1, pageSize 3, expectedItems 3, totalCount 10, totalPages 4
+  public async Task ListProducts_ReturnsPagedListOfProducts(
+    int page, 
+    int pageSize, 
+    int expectedItems, 
+    int expectedTotalCount, 
+    int expectedTotalPages)
+  {
+    // Arrange
+    var options = CreateNewContextOptions();
+    var dbContext = new AppDbContext(options);
+    await SeedTestProducts(dbContext);
+    var queryService = new ListProductsQueryService(dbContext);
+
+    // Act
+    var result = await queryService.ListAsync(page, pageSize);
+
+    // Assert
+    result.ShouldNotBeNull();
+    result.Items.Count.ShouldBe(expectedItems);
+    result.TotalCount.ShouldBe(expectedTotalCount);
+    result.Page.ShouldBe(page);
+    result.PerPage.ShouldBe(pageSize);
+    result.TotalPages.ShouldBe(expectedTotalPages);
+
+    // Verify each product has required properties
+    foreach (var product in result.Items)
+    {
+      product.Id.ShouldNotBeNull();
+      product.Name.ShouldNotBeNullOrWhiteSpace();
+      product.UnitPrice.ShouldBeGreaterThan(0);
+    }
+  }
+
+  [Fact]
+  public async Task ListProducts_FirstPage_ReturnsProductsInOrder()
+  {
+    // Arrange
+    var options = CreateNewContextOptions();
+    var dbContext = new AppDbContext(options);
+    await SeedTestProducts(dbContext);
+    var queryService = new ListProductsQueryService(dbContext);
+
+    // Act
+    var result = await queryService.ListAsync(1, 10);
+
+    // Assert
+    result.Items.Count.ShouldBe(10);
+    result.Items.First().Name.ShouldBe("Product 1");
+    result.Items.Last().Name.ShouldBe("Product 10");
+  }
+
+  [Fact]
+  public async Task ListProducts_EmptyDatabase_ReturnsEmptyList()
+  {
+    // Arrange
+    var options = CreateNewContextOptions();
+    var emptyDbContext = new AppDbContext(options);
+    var emptyQueryService = new ListProductsQueryService(emptyDbContext);
+
+    // Act
+    var result = await emptyQueryService.ListAsync(1, 10);
+
+    // Assert
+    result.Items.Count.ShouldBe(0);
+    result.TotalCount.ShouldBe(0);
+    result.TotalPages.ShouldBe(0);
+  }
+}