如何在 C# 中对 HTTP 处理程序进行单元测试

Question

I want to unit Test my HTTP Handlers. I am Using XUnit framework for unit testing, My Sample Handler Code is

 public class MyHandler : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";
            context.Response.Write("Hello World");
            var data = context.Request.InputStream;
            //Here logic read the context.Request.InputStream
            //All the data will be posted to this Stream
            //Calling of business logic layer Methods
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }

I am new to Unit testing and I just want to know What are the possible test cases for testing my HandleS Since the return type of handlers is Void so I am confuse how can I write the Test for Handlers...

Note : I know HttpContextBase can called using an HttpContextWrapper, I am not asking this I am just asking What are the possible test cases for HttpHandlers

Answer 1

Testing void methods is an interesting topic. The main way I would go about it is to mock up an HTTP Context, and pass it in as a parameter. Then, you should be asserting on the things you are setting that HTTP context to do within your method. For example Assert.Equal("text/plain", myHttpContext.Response.ContentType); However, you need to ensure that you are creating a unit test. It says you have business logic after this step. Have you inverted your dependencies? (Passed them as parameters into the method). Are you able to mock things out appropriately? Make sure the method isn't doing an actual HTTP call (if it is a unit test). In general, I recommend less void methods with side affects but in legacy it can't be avoided. To address your initial question, test cases are going to be anything you logically expect. Did I set my route correctly? Am I expecting the content to be text? Is my payload accurate? Anything you change is a potential test, but ensure you are testing to acceptance criteria. Its okay to have multiple assertions in a test if its one logical assert.