im单元测试我的家庭控制器.此测试工作正常,直到我添加了一个保存图像的新功能.
导致问题的方法如下.
public static void SaveStarCarCAPImage(int capID)
{
byte[] capBinary = Motorpoint2011Data.RetrieveCapImageData(capID);
if (capBinary != null)
{
MemoryStream ioStream = new MemoryStream();
ioStream = new MemoryStream(capBinary);
// save the memory stream as an image
// Read in the data but do not close,before using the stream.
using (Stream originalBinaryDataStream = ioStream)
{
var path = HttpContext.Current.Server.MapPath("/StarVehiclesImages");
path = System.IO.Path.Combine(path,capID + ".jpg");
Image image = Image.FromStream(originalBinaryDataStream);
Image resize = image.GetThumbnailImage(500,375,null,new IntPtr());
resize.Save(path,System.Drawing.Imaging.ImageFormat.Jpeg);
}
}
}
当调用来自单元测试时,HttpContext.Current为null并抛出异常.在阅读有关Moq和有关使用Moq与会话的一些教程之后,确保可以完成.
到目前为止,这个单元测试代码已经提出,但是问题是HTTPContext.Current总是为空,并且仍然抛出异常.
protected ControllerContext CreateStubControllerContext(Controller controller)
{
var httpContextStub = new Mock<HttpContextBase>
{
DefaultValue = DefaultValue.Mock
};
return new ControllerContext(httpContextStub.Object,new RouteData(),controller);
}
[TestMethod]
public void Index()
{
// Arrange
HomeController controller = new HomeController();
controller.SetFakeControllerContext();
var context = controller.HttpContext;
Mock.Get(context).Setup(s => s.Server.MapPath("/StarVehiclesImages")).Returns("My Path");
// Act
ViewResult result = controller.Index() as ViewResult;
// Assert
HomePageModel model = (HomePageModel)result.Model;
Assert.AreEqual("Welcome to ASP.NET MVC!",model.Message);
Assert.AreEqual(typeof(List<Vehicle>),model.VehicleMakes.GetType());
Assert.IsTrue(model.VehicleMakes.Exists(x => x.Make.Trim().Equals("Ford",StringComparison.OrdinalIgnoreCase)));
}
解决方法
HttpContext.Current是你绝对不会使用的东西,如果你期望你的代码进行单元测试.这是一个静态方法,如果没有Web上下文,只需返回null,这是单元测试的情况,不能被嘲笑.因此,重构代码的一种方法如下：
public static void SaveStarCarCAPImage(int capID,string path)
{
byte[] capBinary = Motorpoint2011Data.RetrieveCapImageData(capID,path);
if (capBinary != null)
{
MemoryStream ioStream = new MemoryStream();
ioStream = new MemoryStream(capBinary);
// save the memory stream as an image
// Read in the data but do not close,before using the stream.
using (Stream originalBinaryDataStream = ioStream)
{
path = System.IO.Path.Combine(path,capID + ".jpg");
Image image = Image.FromStream(originalBinaryDataStream);
Image resize = image.GetThumbnailImage(500,new IntPtr());
resize.Save(path,System.Drawing.Imaging.ImageFormat.Jpeg);
}
}
}
你看,现在这种方法不再依赖于任何Web上下文,可以隔离测试.呼叫者有责任通过正确的路径.
