WebApi的一种集成测试写法(in-memory)

WebApi的一种集成测试写法(in-memory)

 

大家是如何对webApi写测试的呢？

1.利用Fiddler直接做请求，观察response的内容。

2.利用Httpclient做请求，断言response的内容。

3.直接调用webApi的action,这种方式的测试跟真实的调用还是有一定差距，不够完美。

接下来我介绍一种webApi的in-memory调用方法，也能够达到对webApi的测试，并且由于是in-memory调用，效率也比较高，非常适写单元测试。本文参考了In memory client, host and integration testing of your Web API service。

一、首先写一个OrderController用来做测试用

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

public class OrderController : ApiController     {         // GET api/order         public Order Get()         {             return new Order(){Id = 1,Descriptions = "descriptions",Name = "name"};         }           // GET api/order/5         public string Get(int id)         {             return "value";         }           // POST api/order         public Order Post(Order order)         {             return order;         }           // DELETE api/order/5         public void Delete(int id)         {         }     }

二、WebApi的请求过程

webApi的核心是对消息的管道处理，整个核心是有一系列消息处理器(HttpMessageHandler)首尾连接的双向管道，管道头为HttpServer,管道尾为HttpControllerDispatcher,HttpControllerDispatcher负责对controller的激活和action的执行，然后相应的消息逆向流出管道。

所以我们可以利用HttpMessageInvoker将一个请求消息HttpRequestMessage发送到管道中，最后收到的消息HttpResponseMessage就代表一个真实的请求响应。

三、Get请求的测试

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

[Test] public void GetTest() {     string baseAddress = "http://localhost:33203/";       HttpConfiguration config = new HttpConfiguration();     WebApiConfig.Register(config);     config.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;     HttpServer server = new HttpServer(config);     HttpMessageInvoker messageInvoker = new HttpMessageInvoker(server);     CancellationTokenSource cts = new CancellationTokenSource();     HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, baseAddress + "api/order");       using (HttpResponseMessage response = messageInvoker.SendAsync(request, cts.Token).Result)     {         var content = response.Content.ReadAsStringAsync().Result;         var result = JsonConvert.DeserializeObject<Order>(content);           result.Name.Should().Be("name");     } }

四、Post请求的测试

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

[Test] public void PostTest() {     string baseAddress = "http://localhost:33203/";       HttpConfiguration config = new HttpConfiguration();     WebApiConfig.Register(config);     config.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;     HttpServer server = new HttpServer(config);     HttpMessageInvoker messageInvoker = new HttpMessageInvoker(server);     CancellationTokenSource cts = new CancellationTokenSource();     HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, baseAddress + "api/order");     var order = new Order() { Id = 1, Name = "orderName", Descriptions = "orderDescriptions" };     request.Content = new ObjectContent<Order>(order, new JsonMediaTypeFormatter());     using (HttpResponseMessage response = messageInvoker.SendAsync(request, cts.Token).Result)     {         var content = JsonConvert.SerializeObject(order, new JsonSerializerSettings() { ContractResolver = new CamelCasePropertyNamesContractResolver() });         response.Content.ReadAsStringAsync().Result.Should().Be(content);     } }

四、重构

可以看到这两个测试大部分的代码是相同的，都是用来发送请求。因此我们提取一个webApiTestBase类，该基类可以提供InvokeGetRequest,InvokePostRequest,InvokePutRequest等方法

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

public abstract class ApiTestBase     {         public abstract string GetBaseAddress();           protected TResult InvokeGetRequest<TResult>(string api)         {             using (var invoker = CreateMessageInvoker())             {                 using (var cts = new CancellationTokenSource())                 {                     var request = new HttpRequestMessage(HttpMethod.Get, GetBaseAddress() + api);                     using (HttpResponseMessage response = invoker.SendAsync(request, cts.Token).Result)                     {                         var result = response.Content.ReadAsStringAsync().Result;                         return JsonConvert.DeserializeObject<TResult>(result);                     }                 }             }         }           protected TResult InvokePostRequest<TResult, TArguemnt>(string api, TArguemnt arg)         {             var invoker = CreateMessageInvoker();             using (var cts = new CancellationTokenSource())             {                 var request = new HttpRequestMessage(HttpMethod.Post, GetBaseAddress() + api);                 request.Content = new ObjectContent<TArguemnt>(arg, new JsonMediaTypeFormatter());                 using (HttpResponseMessage response = invoker.SendAsync(request, cts.Token).Result)                 {                     var result = response.Content.ReadAsStringAsync().Result;                     return JsonConvert.DeserializeObject<TResult>(result);                 }             }         }           private HttpMessageInvoker CreateMessageInvoker()         {             var config = new HttpConfiguration();             WebApiConfig.Register(config);             var server = new HttpServer(config);             var messageInvoker = new HttpMessageInvoker(server);             return messageInvoker;         }     }

有了这个基类，我们写测试只需要重写方法GetBaseAddress()，然后直接调用基类方法并进行断言即可

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

[TestFixture]     public class OrderApiTests:ApiTestBase     {         public override string GetBaseAddress()         {             return "http://localhost:33203/";         }           [Test]         public void Should_get_order_successfully()         {             var result = InvokeGetRequest<Order>("api/order");               result.Name.Should().Be("name");             result.Descriptions.Should().Be("descriptions");             result.Id.Should().Be(1);         }           [Test]         public void Should_post_order_successfully()         {             var newOrder=new Order(){Name = "newOrder",Id = 100,Descriptions = "new-order-description"};               var result = InvokePostRequest<Order,Order>("api/order", newOrder);               result.Name.Should().Be("newOrder");             result.Id.Should().Be(100);             result.Descriptions.Should().Be("new-order-description");         }     }

是不是干净多了。

这种in-memory的测试方案有什么优点和缺点呢？

优点：

1.模拟真实调用，需要传入api地址即可得到结果，由于整个调用是in-memory的，所有效率很高，很适合集成测试。

2.整个测试时可以调试的，可以直接从单元测试调试进去，如果你写一个httpClient的测试，需要把webApi启动起来，然后。。。麻烦

缺点：我觉得原文作者说的那些缺点都可以忽略不计^_^