c# - 痣和 AppSettingsReader？

Question

我正在与 Moles 一起编写一些单元测试。我在网上搜索过，但没有看到任何关于如何使用 Moles 拦截对 AppSettingsReader.GetValue 的调用的回复。

有没有人能够使用 Moles 做到这一点？或者我是否被迫隔离自己班级中可以注入或模拟的调用？理想情况下，有一种方法可以直接使用 Moles 来拦截调用，因为我们真的不想修改要测试的代码。

谢谢！

Answer 1

首先，我强烈建议迁移到 .NET 4.5 / C# 5 / Visual Studio 2012 中的 Moles 发布版本，称为“Fakes and Stubs”。

System.Configurations 命名空间与 Mole/Fake 类型不兼容，必须被存根。要使用 Moles 框架创建存根，只需为 System.Configuration.AppSettingsReader 类型创建一个接口。Moles 编译器会自动将接口转换为 Stub 类型。

这是您可以添加到项目中的界面：

using System;

namespace YOUR_NAMESPACE_HERE
{
  /// <summary>
  /// IOC object for stubbing System.Configuration.AppSettingsReader.
  /// Provides a method for reading values of a particular type from
  /// the configuration.
  /// </summary>
  interface IAppSettingsReader
  {
    /// <summary>
    /// Gets the value for a specified key from the
    /// System.Configuration.ConfigurationSettings.AppSettings property
    /// and returns an object of the specified type containing the
    /// value from the configuration.
    /// </summary>
    /// <param name="key">The key for which to get the value.</param>
    /// <param name="type">The type of the object to return.</param>
    /// <returns>The value of the specified key</returns>
    /// <exception cref="System.ArgumentNullException">key is null.
    /// - or -
    /// type is null.</exception>
    /// <exception cref="System.InvalidOperationException">key does
    /// not exist in the &lt;appSettings&gt; configuration section.
    /// - or -
    /// The value in the &lt;appSettings&gt; configuration section
    /// for key is not of type type.</exception>
    public object GetValue(string key, Type type);
  }
}

这也是一个存根类：

using System;
using System.Configuration;

namespace YOUR_NAMESPACE_HERE
{
  /// <summary>
  /// Production stub for System.Configuration.AppSettingsReader.
  /// Provides a method for reading values of a particular type from
  /// the configuration.
  /// </summary>
  public class AppSettingsReaderStub : IAppSettingsReader
  {
    /// <summary>
    /// Gets the value for a specified key from the
    /// System.Configuration.ConfigurationSettings.AppSettings property
    /// and returns an object of the specified type containing the value
    /// from the configuration.
    /// </summary>
    /// <param name="key">The key for which to get the value.</param>
    /// <param name="type">The type of the object to return.</param>
    /// <returns>The value of the specified key</returns>
    /// <exception cref="System.ArgumentNullException">key is null.
    /// - or -
    /// type is null.</exception>
    /// <exception cref="System.InvalidOperationException">key does not
    /// exist in the &lt;appSettings&gt; configuration section.
    /// - or -
    /// The value in the &lt;appSettings&gt; configuration section for
    /// key is not of type type.</exception>
    public object GetValue(string key, Type type)
    {
      var reader = new AppSettingsReader();
      object result = reader.GetValue(key, type);
      return result;
    }
  }
}