三、单元测试--确保控制器按照希望执行：
单元测试是小型的脚本化测试，通常以与产品代码同样的语言来编写。它们以与系统其余部分隔离的形式来建立并演练单个组件的功能，目的是证实它能正确工作。
1.已提供的测试项目：
如果在新建项目时勾选了“创建单元测试项目”选项，Visual Studio会用Visual Studio Unit Testing Framework(Visual Studio单元测试框架)生成一个测试项目，包含HomeControllerTest类：
1 namespace Guestbook.Tests.Controllers
2 {
3 [TestClass]
4 public class HomeControllerTest
5 {
6 [TestMethod]
7 public void Index()
8 {
9 // Arrange
10 HomeController controller = new HomeController();//实例化控制器
11
12 // Act
13 ViewResult result = controller.Index() as ViewResult;//演练动作方法
14
15 // Assert
16 Assert.IsNotNull(result);//断言结果
17 }
18
19 [TestMethod]
20 public void About()
21 {
22 // Arrange
23 HomeController controller = new HomeController();
24
25 // Act
26 ViewResult result = controller.About() as ViewResult;
27
28 // Assert
29 Assert.AreEqual("Your application description page.", result.ViewBag.Message);
30 }
31
32 [TestMethod]
33 public void Contact()
34 {
35 // Arrange
36 HomeController controller = new HomeController();
37
38 // Act
39 ViewResult result = controller.Contact() as ViewResult;
40
41 // Assert
42 Assert.IsNotNull(result);
43 }
44 }
每个测试都有三个阶段--Arrange(准备)、Act(动作)、Assert(断言)。通常将这种编写测试的模式称为“A/A/A”模式或“3A”模式。让单元测试采用这种固定的A/A/A编程模式有利于编写格式统一的测试。
2.测试GuestbookController：
在之前的代码中GuestbookController直接实例化并使用GuestbookContext对象访问数据库。这意味着如果没有建好数据库或者数据库中没有测试数据，就不能对控制器进行测试。
代替上述对GuestbookContext的直接访问，我们引入一个存储库，让它提供一个对GuestbookEntry对象执行数据访问操作的网关：
1.新增接口：
1 namespace Guestbook.Repository
2 {
3 public interface IGuestbookRepository
4 {
5 IList<GuestbookEntry> GetMostRecentEntries();
6 GuestbookEntry FindById(int? id);
7 IList<CommentSummary> GetCommentSummary();
8 void AddEntry(GuestbookEntry entry);
9 void Edit(GuestbookEntry entry);
10 void DeleteById(int id);
11 }
12 }
2.实现接口：
1 namespace Guestbook.Repository
2 {
3 public class GuestbookRepository : IGuestbookRepository
4 {
5 private GuestbookContext _db = new GuestbookContext();
6 public IList<GuestbookEntry> GetMostRecentEntries()
7 {
8 return (from entry in _db.Entries
9 orderby entry.DateAdded descending
10 select entry).Take(20).ToList();
11 }
12 public void AddEntry(GuestbookEntry entry)
13 {
14 _db.Entries.Add(entry);
15 _db.SaveChanges();
16 }
17 public GuestbookEntry FindById(int? id)
18 {
19 var entry = _db.Entries.Find(id);
20 return entry;
21 }
22 public IList<CommentSummary> GetCommentSummary()
23 {
24 var entries = from entry in _db.Entries
25 group entry by entry.Name into groupedByName
26 orderby groupedByName.Count() descending
27 select new CommentSummary
28 {
29 NumberOfComments=groupedByName.Count(),
30 UserName=groupedByName.Key
31 };
32 return entries.ToList();
33
34 }
35 public void Edit(GuestbookEntry entry)
36 {
37 _db.Entry(entry).State = EntityState.Modified;
38 _db.SaveChanges();
39 }
40 public void DeleteById(int id)
41 {
42 var entry = _db.Entries.Find(id);
43 _db.Entries.Remove(entry);
44 _db.SaveChanges();
45 }
46 }
47 }
3.修改GuestbookController：
1 namespace Guestbook.Controllers
2 {
3 public class GuestbookController : Controller
4 {
5 private IGuestbookRepository _repository;
6
7 public GuestbookController()
8 {
9 _repository = new GuestbookRepository();
10 }
11
12 public GuestbookController(IGuestbookRepository repository)
13 {
14 _repository = repository;
15 }
16 public ActionResult Index()
17 {
18 var mostRecentEntries=_repository.GetMostRecentEntries();
19 return View(mostRecentEntries);
20 }
21 public ActionResult Details(int? id)
22 {
23 if (id == null)
24 {
25 return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
26 }
27 var entry = _repository.FindById(id);
28 if (entry == null)
29 {
30 return HttpNotFound();
31 }
32 return View(entry);
33 }
34 public ActionResult Create()
35 {
36 return View();
37 }
38 [HttpPost]
39 [ValidateAntiForgeryToken]
40 public ActionResult Create([Bind(Include="Id,Name,Message,DateAdded")] GuestbookEntry entry)
41 {
42 if (ModelState.IsValid)//检查验证是否成功
43 {
44 _repository.AddEntry(entry);
45 return RedirectToAction("Index");
46 }
47
48 return View(entry);//失败时重新渲染表单
49 }
50 public ActionResult Edit(int? id)
51 {
52 if (id == null)
53 {
54 return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
55 }
56 var entry = _repository.FindById(id);
57 if (entry == null)
58 {
59 return HttpNotFound();
60 }
61 return View(entry);
62 }
63 [HttpPost]
64 [ValidateAntiForgeryToken]
65 public ActionResult Edit([Bind(Include="Id,Name,Message,DateAdded")] GuestbookEntry entry)
66 {
67 if (ModelState.IsValid)
68 {
69 _repository.Edit(entry);
70 return RedirectToAction("Index");
71 }
72 return View(entry);
73 }
74 public ActionResult Delete(int? id)
75 {
76 if (id == null)
77 {
78 return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
79 }
80 var entry = _repository.FindById(id);
81 if (entry == null)
82 {
83 return HttpNotFound();
84 }
85 return View(entry);
86 }
87 [HttpPost, ActionName("Delete")]
88 [ValidateAntiForgeryToken]
89 public ActionResult DeleteConfirmed(int id)
90 {
91 _repository.DeleteById(id);
92 return RedirectToAction("Index");
93 }
94
95 public ActionResult CommentSumary()
96 {
97 var entries = _repository.GetCommentSummary();
98 return View(entries.ToList());
99 }
100 }
101 }
4.不与数据库交互的IGuestbookRepository接口的模仿实现：
1 namespace Guestbook.Repository
2 {
3 public class FakeGuestbookRepository:IGuestbookRepository
4 {
5 public List<GuestbookEntry> _entries = new List<GuestbookEntry>();
6 public IList<GuestbookEntry> GetMostRecentEntries()
7 {
8 return new List<GuestbookEntry>
9 {
10 new GuestbookEntry
11 {
12 DateAdded=new DateTime(2014,11,13),
13 Id=1,
14 Message="Test Message",
15 Name="陈家洛"
16 }
17 };
18 }
19 public void AddEntry(GuestbookEntry entry)
20 {
21 _entries.Add(entry);
22 }
23 public GuestbookEntry FindById(int? id)
24 {
25 return _entries.SingleOrDefault(x => x.Id == id);
26 }
27 public IList<CommentSummary> GetCommentSummary()
28 {
29 return new List<CommentSummary>
30 {
31 new CommentSummary
32 {
33 UserName="陈家洛",
34 NumberOfComments=3
35 }
36 };
37
38 }
39 public void Edit(GuestbookEntry entry)
40 {
41 //
42 }
43 public void DeleteById(int id)
44 {
45 //
46 }
47 }
48 }
5.测试Index动作：
1 namespace Guestbook.Tests.Controllers
2 {
3 [TestClass]
4 public class GuestbookControllerTest
5 {
6 [TestMethod]
7 public void Index_RendersView()
8 {
9 var controller = new GuestbookController(new FakeGuestbookRepository());
10 var result=controller.Index() as ViewResult;
11 Assert.IsNotNull(result);
12 }
13 [TestMethod]
14 public void Index_gets_most_rencent_entries()
15 {
16 var controller = new GuestbookController(new FakeGuestbookRepository());
17 var result=(ViewResult)controller.Index();
18 var entries=(IList<GuestbookEntry>) result.Model;
19 Assert.AreEqual(1,entries.Count);
20 }
21
22 }
23 }
第一个测试调用Index动作，并简单断言它渲染一个视图；第二个断言传递给视图一个GuestbookEntry对象列表。
源码下载 密码：bwmq
时间： 2024-10-12 19:00:21