使用MS假冒品进行单元测试：HttpClient并等待

Question

我有创建HttpClient实例并调用某些方法并以异步模式返回响应的类。

对于ReadAsAsync，我使用了nuget包“ System.Net.Http.Formatting”。

源代码：

    public class MyClass
    {
        readonly HttpClient client = new HttpClient();       
        public MyClass()
        {
             string myUrl = ConfigurationManager.AppSettings["MyWebAPI"];
             client.BaseAddress = new Uri(myUrl);
        }
        public async Task<List<YourClass>> GetYourClass()
        {
            var filters = "string";
            HttpResponseMessage response = await client.GetAsync(filters).ConfigureAwait(false);

            if (response.IsSuccessStatusCode)
            {
                var notes = await response.Content.ReadAsAsync<List<YourClass>>();
                return notes;
            }
            return null;
        }
    }
    public class YourClass
    {
        private string Address { get; set; }

        public YourClass(string address)
        {
            Address = address;
        }       
    }

单元测试：

    [TestClass]
    public class UnitTest1
    {
        [TestMethod]
        public void TestMethod1()
        {
            using (ShimsContext.Create())
            {
                MyClass obj = new MyClass();
                ShimHttpClient shimHttpClient = new ShimHttpClient();
                ShimHttpClient.Constructor = (t) =>
                {
                    shimHttpClient = new ShimHttpClient();
                    shimHttpClient.GetAsyncString = (a) =>
                    {
                        return new System.Threading.Tasks.Task<System.Net.Http.HttpResponseMessage>(function1);
                    };
                };
                var returnVal = obj.GetYourClass();
            }
        }

        private System.Net.Http.HttpResponseMessage function1()
        {
            return new System.Net.Http.HttpResponseMessage();
        }
    }

我们无法更改源代码。 但需要通过虚拟调用测试对GetAsync和ReadAsAync调用进行单元测试。

Answer 1

声明您的测试要异步运行并等待源类的响应

[TestMethod]
public async Task TestMethod1()
{
    using (ShimsContext.Create())
    {
        MyClass obj = new MyClass();
        ShimHttpClient shimHttpClient = new ShimHttpClient();
        ShimHttpClient.Constructor = (t) =>
        {
            shimHttpClient = new ShimHttpClient();
            await shimHttpClient.GetAsyncString = (a) =>
            {
                return new System.Threading.Tasks.Task<System.Net.Http.HttpResponseMessage>(function1);
            };
        };
        var returnVal = await obj.GetYourClass();
        Assert.IsNotNull(returnVal);
        //make more assertations on the returnVal 
    }
}