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如何在XUnit单元测试中使用microsoft.extensions.configuration.iconiguration

xunit.net xunit asp.net-core-2.0 asp.net-core-mvc unit-testing

Learning Curve · 技术社区 · 7 年前

在我的ASP.NET Core 2.0应用程序中,我尝试对使用 Microsoft.extensions.configuration.icon配置 依赖注入。我用的是Xunit,不知道怎么通过 IConfiguration 从我的单元测试课。我尝试了以下实现并得到了错误

消息:以下构造函数参数没有匹配的fixture数据:IConfiguration配置。

我对测试框架非常陌生,甚至不知道是否可以像我在代码片段中所做的那样使用依赖注入。

我的单元测试课程如下

public class SqlRestaurantDataCLUnitTest
{
    private readonly IConfiguration configuration;
    public SqlRestaurantDataCLUnitTest(IConfiguration configuration)
    {
        this.configuration = configuration;
    }
    [Fact]
    public void AddTest()
    {
        var restaurantDataCL = new SqlRestaurantDataCL(configuration);
        var restaurant = new Restaurant
        {
            Name = "TestName",
            Cuisine = CuisineType.None
        };

        var result = restaurantDataCL.Add(restaurant);

        Assert.IsNotType(null, result.Id);    
    }
}

我的数据服务层如下

public class SqlRestaurantDataCL : IRestaurantDataCL
{
    private readonly IConfiguration configuration;
    public SqlRestaurantDataCL(IConfiguration configuration)
    {
        this.configuration = configuration;
    }
    public Restaurant Add(Restaurant restaurant)
    {
        using (var db = GetConnection())
        {
            string insertSql = @"INSERT INTO [dbo].[RESTAURANTS]([Cuisine], [Name]) 
                                OUTPUT INSERTED.*
                                VALUES (@Cuisine, @Name)";

            restaurant = db.QuerySingle<Restaurant>(insertSql, new
            {
                Cuisine = restaurant.Cuisine,
                Name = restaurant.Name
            });

            return restaurant;
        }
    }

    private IDbConnection GetConnection()
    {
        return new SqlConnection(configuration.GetSection(Connection.Name).Value.ToString());
    }
}

public class Connection
{
    public static string Name
    {
        get { return "ConnectionStrings: OdeToFood"; }
    }
}

1 回复 | 直到 7 年前

Nkosi 7 年前

单元测试有一个非常有用的暴露设计问题的习惯。在本例中,由于与框架关注点以及静态关注点的紧密耦合,您已经做出了一些设计选择,这些选择被证明很难测试。

首先,看起来 SqlRestaurantDataCL 实际上取决于连接工厂

public interface IDbConnectionFactory {
    IDbConnection GetConnection();
}

它将根据建议重构数据实现,以依赖于该抽象。

public class SqlRestaurantDataCL : IRestaurantDataCL {
    private readonly IDbConnectionFactory factory;

    public SqlRestaurantDataCL(IDbConnectionFactory factory) {
        this.factory = factory;
    }
    public Restaurant Add(Restaurant restaurant) {
        using (var connection = factory.GetConnection()) {
            string insertSql = @"INSERT INTO [dbo].[RESTAURANTS]([Cuisine], [Name]) 
                                OUTPUT INSERTED.*
                                VALUES (@Cuisine, @Name)";

            restaurant = connection.QuerySingle<Restaurant>(insertSql, new {
                Cuisine = restaurant.Cuisine,
                Name = restaurant.Name
            });

            return restaurant;
        }
    }

    //...
}

假设dapper正用于进行上述查询。

通过引入抽象的依赖项,可以在隔离测试时根据需要模拟它们。

public class SqlRestaurantDataCLUnitTest {

    [Fact]
    public void AddTest() {
        //Arrange
        var connection = new Mock<IDbConnection>();
        var factory = new Mock<IDbConnectionFactory>();
        factory.Setup(_ => _.GetConnection()).Returns(connection.Object);

        //...setup the connection to behave as expected

        var restaurantDataCL = new SqlRestaurantDataCL(factory.Object);
        var restaurant = new Restaurant {
            Name = "TestName",
            Cuisine = CuisineType.None
        };

        //Act
        var result = restaurantDataCL.Add(restaurant);

        //Assert
        Assert.IsNotType(null, result.Id);
    }
}

现在,如果您打算实际接触真实的数据库,那么这不是一个隔离单元测试,而是一个集成测试,它将采用不同的方法。

在生产代码中,工厂可以实现

public class SqlDbConnectionFactory : IDbConnectionFactory {
    private readonly ConnectionSetings connectionSettings;

    SqlDbConnectionFactory(ConnectionSetings connectionSettings) {
        this.connectionSettings = connectionSettings;
    }

    public IDbConnection GetConnection() {
        return new SqlConnection(connectionSettings.Name));
    }
}

在哪里? ConnectionSetings 定义为存储连接字符串的简单POCO

public class ConnectionSetings {
    public string Name { get; set; }
}

在合成根目录中,可以从配置中提取设置。

IConfiguration Configuration; //this would have been set previously

public void ConfigureServices(IServiceCollection services) {
    //...

    var settings = Configuration
        .GetSection("ConnectionStrings:OdeToFood")
        .Get<ConnectionSetings>();

    //...verify settings (if needed)

    services.AddSingleton(settings);
    services.AddSingleton<IDbConnectionFactory,SqlDbConnectionFactory>();
    services.AddSingleton<IRestaurantDataCL,SqlRestaurantDataCL>();
    //Note: while singleton was used above, You can decide to use another scope
    //      if so desired.
}

真的没必要路过 IConfiguration 因为它更像是一个框架问题,实际上只在启动时才相关。