Mock HttpContext for unit testing a .NET core MVC controller?

问题:

I have a function in a controller that I am unit testing that expects values in the header of the http request. I can't initialize the HttpContext because it is readonly.

My controller function expects a http request header value for "device-id"

[TestMethod] public void TestValuesController() {     ValuesController controller = new ValuesController();      //not valid controller.HttpContext is readonly     //controller.HttpContext = new DefaultHttpContext();       var result = controller.Get();     Assert.AreEqual(result.Count(), 2); } 

Is there a straight-forward way to do this without using a third party library?

回答1:

I was able to initialize the httpcontext and header in this way:

[TestMethod] public void TestValuesController() {     ValuesController controller = new ValuesController();     controller.ControllerContext = new ControllerContext();     controller.ControllerContext.HttpContext = new DefaultHttpContext();     controller.ControllerContext.HttpContext.Request.Headers["device-id"] = "20317";     var result = controller.Get();     //the controller correctly recieves the http header key value pair device-id:20317     ... } 

回答2:

Rather than mocking out the HTTPContext, it is probably a better idea to map the header into a parameter on the method. For example, in the controller at the bottom of this answer, the id parameter is set to the value header with a name equal to "device-id"... The unit test then becomes

[TestMethod] public void TestValuesController() {     ValuesController controller = new ValuesController();     var result = controller.GetHeaderValue("27");     Assert.AreEqual(result, "27"); } 

While you can mock the HttpContext, in my opinion it is something that should be avoided unless you have no choice. The documentation for the FromHeaderAttribute can be found here FromHeaderAttribute Class.

    public class ValuesController: Controller     {        public string GetHeaderValue([FromHeader(Name = "device-id")] string id)       {         return id;       }     } 

文章来源: Mock HttpContext for unit testing a .NET core MVC controller?