ASP.NET MVC单元测试Controller时添加上下文的方式

在ASP.NET MVC中测试Controller时，常常需要在Controller中访问上下文，比方说查询字符串或者form中的内容，而我们测试的时候一般不是在web运行环境下的，所以我们需要做些工作去模拟上下文。

Controller中代码如下

public ActionResult Index()
        {
            ViewData["Message"] = Request.QueryString["lfm"];

            return View();
        }

测试写法如下：

[TestMethod]
        public void Index()
        {
            HomeController controller = new HomeController();
         
            var httpContext = new Mock<HttpContextBase>();
            var request=new Mock<HttpRequestBase>();
            NameValueCollection queryString = new NameValueCollection();
            queryString.Add("lfm", "lfm");
            request.Setup(r => r.QueryString).Returns(queryString);
            httpContext.Setup(ht => ht.Request).Returns(request.Object);

            ControllerContext controllerContext = new ControllerContext();
            controllerContext.HttpContext = httpContext.Object;
            controller.ControllerContext = controllerContext;

            ViewResult result = controller.Index() as ViewResult;

            ViewDataDictionary viewData = result.ViewData;
            Assert.AreEqual("lfm", viewData["Message"]);
        }

这里用到了Mock可以参考：

MoQ(基于.net3.5,c#3.0的mock框架)简单介绍

如果是form稍作修改即可：

 public ActionResult About()
        {
            ViewData["Message"] = Request.Form["lfm"];
            return View();
        }

测试代码：

[TestMethod]
        public void About()
        {
            // Arrange
            HomeController controller = new HomeController();
            var httpContext = new Mock<HttpContextBase>();
            var request = new Mock<HttpRequestBase>();
            NameValueCollection queryString = new NameValueCollection();
            queryString.Add("lfm", "lfm");
            request.Setup(r => r.Form).Returns(queryString);
            httpContext.Setup(ht => ht.Request).Returns(request.Object);

            ControllerContext controllerContext = new ControllerContext();
            controllerContext.HttpContext = httpContext.Object;
            controller.ControllerContext = controllerContext;
            // Act
            ViewResult result = controller.About() as ViewResult;

            // Assert
            ViewDataDictionary viewData = result.ViewData;
            Assert.AreEqual("lfm", viewData["Message"]);
        }