单元测试mock当前时间

在实际项目中很多地方用到DateTime.Now，这个时间是时时变化的。如果要进行单元测试对比预期结果时，这个时间无法预测，可以添加如下两个时间类

namespace Common.Helper
{/// <summary>/// 获取当前时间/// However, when unit testing with static state, always remember to tear down your fixture by calling ./// </summary>public abstract class TimeProvider{private static TimeProvider current =DefaultTimeProvider.Instance;public static TimeProvider Current{get { return TimeProvider.current; }set{if (value == null){throw new ArgumentNullException("value");}TimeProvider.current = value;}}public abstract DateTime Now { get; }public static void ResetToDefault(){TimeProvider.current = DefaultTimeProvider.Instance;}}public class DefaultTimeProvider : TimeProvider{private readonly static DefaultTimeProvider instance =new DefaultTimeProvider();private DefaultTimeProvider() { }public override DateTime Now{get { return DateTime.Now; }}public static DefaultTimeProvider Instance{get { return DefaultTimeProvider.instance; }}}
}

在实际代码中使用方法：

var now = TimeProvider.Current.Now;

单元测试模拟方法：

var timeMock = new Mock<TimeProvider>();
timeMock.SetupGet(tp => tp.Now).Returns(new DateTime(2010, 3, 11));
TimeProvider.Current = timeMock.Object;

 

需要用到moq4模拟对象