Asp.NetWebAPIユニットテスト

今Netwebapiの運用はますます多くなり、そのユニットもますます重要になっています.一般的なソフトウェア開発は多層構造であり,上層は下層のインタフェースを呼び出すが,各層の実装者は異なり,一般的には自己対応ユニットテストのみを書く.下層への依存はIOCを通じて行います.まず、Controllerの定義と実装を見てみましょう.

 public class ArticlesController : ApiController
    {
        private IArticleService _articleService;

        public ArticlesController(IArticleService articleService)
        {
            _articleService = articleService;
        }

        // GET: api/Articles
        public IEnumerable<Article> GetArticles()
        {
            return _articleService.GetArticles();
        }

        // GET: api/Articles/5
        [ResponseType(typeof(Article))]
        public IHttpActionResult GetArticle(int id)
        {
            Article article = _articleService.GetArticle(id);
            if (article == null)
            {
                return NotFound();
            }

            return Ok(article);
        }

        // PUT: api/Articles/5
        [ResponseType(typeof(void))]
        public IHttpActionResult PutArticle(int id, Article article)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            if (id != article.ID)
            {
                return BadRequest();
            }
            try
            {
                _articleService.UpdateArticle(article);
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!ArticleExists(id))
                {
                    return NotFound();
                }
                else
                {
                    throw;
                }
            }

            return StatusCode(HttpStatusCode.NoContent);
        }

        // POST: api/Articles
        [ResponseType(typeof(Article))]
        public IHttpActionResult PostArticle(Article article)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            _articleService.CreateArticle(article);

            return CreatedAtRoute("DefaultApi", new { id = article.ID }, article);
        }

        // DELETE: api/Articles/5
        [ResponseType(typeof(Article))]
        public IHttpActionResult DeleteArticle(int id)
        {
            Article article = _articleService.GetArticle(id);
            if (article == null)
            {
                return NotFound();
            }

            _articleService.DeleteArticle(article);

            return Ok(article);
        }

        private bool ArticleExists(int id)
        {
            return _articleService.GetArticle(id) != null;
        }
    }

まず、コンストラクション関数にはIArticleServiceインスタンスが必要であり、Controllerのactionでこのサービスが必要になります.【ここのコントロールはとても簡単で、ユニットテストは不要だと言わないでください.実際のプロジェクトでは、コントロールラーのユニットテストをしないために、その中のロジックをすべて抽出してHelperの中に入れて、Helperにユニットテストをする人がいます】
IOCの実現:
ここではUnityを使っているので、まずInstall-Package Unityをインストールする必要があります.WebApi.5.1

  public class WebApiApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
            GlobalConfiguration.Configure(WebApiConfig.Register);
            //Install-Package Unity.WebApi.5.1
            IUnityContainer container = new UnityContainer()
            .RegisterType<IArticleService, ArticleService>()
            .RegisterType<IBlogService, BlogService>();
  
            //GlobalConfiguration.Configuration.DependencyResolver = new UnityDependencyResolver(container);
              GlobalConfiguration.Configuration.Services.Replace(typeof(IHttpControllerActivator), new UnityHttpControllerActivator(container));
        }
    }
    public class UnityHttpControllerActivator : IHttpControllerActivator
    {
        public IUnityContainer UnityContainer { get; private set; }
        public UnityHttpControllerActivator(IUnityContainer unityContainer)
        {
            this.UnityContainer = unityContainer;
        }

        public IHttpController Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)
        {
            return (IHttpController)this.UnityContainer.Resolve(controllerType);
        }
    }

一般的に我々のコントローラはDependencyResolverとIHttpControllerActivvatorのみで制御反転を実現している.
ユニットテストは普通Moqとnunitを使うので、Install-Package MoqとInstall-Package NUnitが必要です.
ユニットテストのcodeは以下の通りです.

  public void TestPostArticle()
        {
            var article = new Article
            {
                Title = "Web API Unit Testing",
                URL = "https://chsakell.com/web-api-unit-testing",
                Author = "Chris Sakellarios",
                DateCreated = DateTime.Now,
                Contents = "Unit testing Web API.."
            };

            var _articlesController = new ArticlesController(_articleService)
            {
                Configuration = new HttpConfiguration(),
                Request = new HttpRequestMessage
                {
                    Method = HttpMethod.Post,
                    RequestUri = new Uri("http://localhost/api/articles")
                }
            };
            var result = _articlesController.PostArticle(article) as CreatedAtRouteNegotiatedContentResult<Article>;

            Assert.That(result.RouteName, Is.EqualTo("DefaultApi"));
            Assert.That(result.Content.ID, Is.EqualTo(result.RouteValues["id"]));
            Assert.That(result.Content.ID, Is.EqualTo(_randomArticles.Max(a => a.ID)));
        }

コントローラのインスタンスの場合はIArticleServiceインスタンスを直接渡します.

  public static   IArticleService GetIArticleService()
        {
   
            var _article = new Mock<IArticleService>();
            _article.Setup(x => x.GetArticles(It.IsAny<string>())).Returns(new Func<string, List<Article>>(name =>
            {
                if (string.IsNullOrEmpty(name))
                {
                    return _randomArticles;
                }
                else
                {
                    return _randomArticles.FindAll(x => x.Title.Contains(name));
                }

            }));
            _article.Setup(x => x.GetArticle(It.IsAny<int>())).Returns(new Func<int, Article>(id =>
            {
                return _randomArticles.Find(x => x.ID == id);
            }));
            _article.Setup(x => x.GetArticle(It.IsAny<string>())).Returns(new Func<string, Article>(name =>
            {
                return _randomArticles.Find(x => x.Title == name);
            }));
            _article.Setup(r => r.CreateArticle(It.IsAny<Article>()))
               .Callback(new Action<Article>(newArticle =>
               {
                   newArticle.DateCreated = DateTime.Now;
                   newArticle.ID = _randomArticles.Last().ID + 1;
                   _randomArticles.Add(newArticle);
               }));

            _article.Setup(r => r.UpdateArticle(It.IsAny<Article>()))
                .Callback(new Action<Article>(x =>
                {
                    var oldArticle = _randomArticles.Find(a => a.ID == x.ID);
                    oldArticle.DateEdited = DateTime.Now;
                    oldArticle.URL = x.URL;
                    oldArticle.Title = x.Title;
                    oldArticle.Contents = x.Contents;
                    oldArticle.BlogID = x.BlogID;
                }));
            return _article.Object;
        }

WebApiは一般的にインタフェースを提供するために使用されるため、使用者はhttpリクエストを送信してデータを取得することが多い.このような方法でユニットテストを行うこともできます.

  public void TestPostArticle2()
        {
            var article = new Article
            {
                Title = "Web API Unit Testing2",
                URL = "https://chsakell.com/web-api-unit-testing",
                Author = "Chris Sakellarios",
                DateCreated = DateTime.Now,
                Contents = "Unit testing Web API.."
            };
            var address = "http://localhost:9000/";

            using (WebApp.Start<Startup>(address))
            {
                HttpClient _client = new HttpClient();
                var response = _client.PostAsJsonAsync<Article>(address + "api/articles/", article).Result;
                var result = response.Content.ReadAsAsync<Article>().Result;
                Assert.That(result.Title, Is.EqualTo(article.Title));
                Assert.That(_randomArticles.Last().Title, Is.EqualTo(article.Title));
            }


        }

では、このウェブプログラムをどのように構築し、IOCをどのように使用するか、
ここでIOCはAutofacを使用しており、そのパッケージは以下の通りです.
Install-Package OwinInstall-Package Microsoft.AspNet.WebApi.OwinInstall-Package Microsoft.Owin.Host.HttpListenerInstall-Package Microsoft.Owin.HostingInstall-Package AutofacInstall-Package Autofac.WebApi2

 public class Startup
    {
        public void Configuration(IAppBuilder appBuilder)
        {
            var config = new HttpConfiguration();
           // config.Services.Replace(typeof(IAssembliesResolver), new CustomAssembliesResolver());

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );

            var builder = new ContainerBuilder();
            builder.RegisterApiControllers(typeof(ArticlesController).Assembly);

            var _articleService = Helper.GetIArticleService();
            builder.RegisterInstance(_articleService).As<IArticleService>();

            
            IContainer container = builder.Build();
            config.DependencyResolver = new AutofacWebApiDependencyResolver(container);

            appBuilder.UseWebApi(config);
        }
    }

参照先:
ASP.NET Web API Unit Testing
Net 4.5でのHttpClient試用
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