将SeedData注入自定义WebApplicationFactory的最佳方法

Question

我在集成测试中剽窃了来自mightysoft docs站点的以下代码，并对其稍加修改以满足我的需求：

public class CustomWebApplicationFactory<TStartup>
    : WebApplicationFactory<TStartup> where TStartup : class
{
    private readonly SeedDataClass _seed;

    public CustomWebApplicationFactory(SeedDataClass seed)
    {
        _seed = seed;
    }

    protected override void ConfigureWebHost(IWebHostBuilder builder)
    {
        base.ConfigureWebHost(builder);
        builder.UseEnvironment("Development");
        builder.ConfigureServices(services =>
        {
            var serviceProvider = new ServiceCollection()
                .AddEntityFrameworkInMemoryDatabase()
                .BuildServiceProvider();

            services.AddSingleton(_seed);

            services.AddDbContextPool<GatewayContext>(options =>
            {
                options.UseInMemoryDatabase("InMemoryDbForTesting");
                options.UseInternalServiceProvider(serviceProvider);
                options.EnableSensitiveDataLogging();
            });

            var sp = services.BuildServiceProvider();

            using (var scope = sp.CreateScope())
            {
                var scopedServices = scope.ServiceProvider;
                var db = scopedServices.GetRequiredService<GatewayContext>();
                var logger = scopedServices
                    .GetRequiredService<ILogger<CustomWebApplicationFactory<TStartup>>>();

                var seed = scopedServices.GetRequiredService<SeedDataClass>();

                db.Database.EnsureCreated();

                try
                {
                    seed.InitializeDbForTests(db);
                }
                catch (Exception ex)
                {
                    logger.LogError(ex, $"An error occurred seeding the database with test messages. Error: {ex.Message}");
                }
            }
        });
    }
}

用于测试，如：

_client = new CustomWebApplicationFactory<Startup>(new SeedDataClass()).CreateClient();

这一切都是可行的，但我希望将泛型添加到定制的web应用程序工厂类中，并将这段代码移动到我正在进行内部测试工作的nuget包中。

就像这样：

public class CustomWebApplicationFactory<TStartup, TContext>
    : WebApplicationFactory<TStartup> 
    where TStartup : class 
    where TContext : DbContext

我被困在如何将SeedDataClass类实例提供/注入到我的新的通用自定义web应用程序工厂中。

Answer 1

这就是我要做的：

弹药厂：

public class GenericWebApplicationFactory<TStartup, TContext, TSeed>
    : WebApplicationFactory<TStartup>
    where TStartup : class
    where TContext : DbContext
    where TSeed : class, ISeedDataClass
{
    protected override void ConfigureWebHost(IWebHostBuilder builder)
    {
        base.ConfigureWebHost(builder);
        builder.UseEnvironment("Development");
        builder.ConfigureServices(services =>
        {
            var serviceProvider = new ServiceCollection()
                .AddEntityFrameworkInMemoryDatabase()
                .BuildServiceProvider();

            services.AddSingleton<ISeedDataClass,TSeed >();

            services.AddDbContextPool<TContext>(options =>
            {
                options.UseInMemoryDatabase("InMemoryDbForTesting");
                options.UseInternalServiceProvider(serviceProvider);
                options.EnableSensitiveDataLogging();
            });

            var sp = services.BuildServiceProvider();
            using (var scope = sp.CreateScope())
            {
                var scopedServices = scope.ServiceProvider;
                var db = scopedServices.GetRequiredService<TContext>();
                var logger = scopedServices.GetRequiredService<ILogger<GenericWebApplicationFactory<TStartup, TContext, TSeed>>>();

                var seeder = scopedServices.GetRequiredService<ISeedDataClass>();

                db.Database.EnsureCreated();

                try
                {
                    seeder.InitializeDbForTests();
                }
                catch (Exception ex)
                {
                    logger.LogError(ex, $"An error occurred seeding the database with test messages. Error: {ex.Message}");
                }
            }
        });
    }
}

已核实的用法：

    _client = new GenericWebApplicationFactory<Startup, GatewayContext, SeedDataClass>().CreateClient();

使用示例种子类：

public interface ISeedDataClass
{
    void InitializeDbForTests();
}

public class SeedDataClass : ISeedDataClass
{
    private readonly GatewayContext _db;

    public SeedDataClass(GatewayContext db)
    {
        _db = db;
    }

    public void InitializeDbForTests()
    {
        _db.Users.AddRange(
            // add some users here
        );

        _db.SaveChanges(true);
    }
}

现在，我可以为内存中的数据库添加种子，但是我认为合适，每个使用它的项目，现在可以将我的GenericWebApplicationFactory推入到helper lib/nuget包中，这些包可以在其他项目中重新使用。

Answer 2

如果您只是试图使类似的构造函数适应您的CustomWebApplicationFactory<TStartup>类的前一个实现

_client = new CustomWebApplicationFactory<Startup>(new SeedDataClass()).CreateClient();

那么您的新构造函数将如下所示：

public class CustomWebApplicationFactory<TStartup, TContext> : WebApplicationFactory<TStartup> 
    where TStartup : class 
    where TContext : DbContext
{
    private readonly SeedDataClass _seed;

    public CustomWebApplicationFactory(SeedDataClass seed)
    {
        if (seed == null) throw new ArgumentNullException(nameof(seed));

        _seed = seed;
    }
}

然后更新对构造函数的调用，如下

new CustomWebApplicationFactory<Startup, YourDbContext>(new SeedDataClass()).CreateClient();