BookStoreWebApplicationFactory.cs

using System.Data.Common;
using BookStoreAPI.Models;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc.Testing;
using Microsoft.Data.Sqlite;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;

namespace BookStoreAPI.Tests;

public class BookStoreWebApplicationFactory<TProgram> : WebApplicationFactory<TProgram> where TProgram : class
{
    protected override void ConfigureWebHost(IWebHostBuilder builder)
    {
        builder.ConfigureServices(services =>
        {
            var dbContextDescriptor =
                services.SingleOrDefault(d => d.ServiceType == typeof(DbContextOptions<BookStoreDatabaseContext>));

            services.Remove(dbContextDescriptor);

            var dbConnectionDescriptor = services.SingleOrDefault(
                d => d.ServiceType == typeof(DbConnection));

            services.Remove(dbConnectionDescriptor);

            services.AddSingleton<DbConnection>(container =>
            {
                var connection = new SqliteConnection("DataSource=:memory:");
                connection.Open();

                return connection;
            });

            services.AddDbContext<BookStoreDatabaseContext>((container, options) =>
            {
                var connection = container.GetRequiredService<DbConnection>();
                options.UseSqlite(connection);
            });

            services.AddAutoMapper(typeof(Program));
        });

        builder.UseEnvironment("Development");
    }
}