ASP.NET Core 对Controller进行单元测试

单元测试对我们的代码质量非常重要。很多同学都会对业务逻辑或者工具方法写测试用例，但是往往忽略了对Controller层写单元测试。我所在的公司没见过一个对Controller写过测试的。今天来演示下如果对Controller进行单元测试。以下内容默认您对单元测试有所了解，比如如何mock一个接口。在这里多叨叨一句，面向接口的好处，除了能够快速的替换实现类（其实大部分接口不会有多个实现），最大的好处就是可以进行mock，可以进行单元测试。

测试Action

下面的Action非常简单，非常常见的一种代码。根据用户id去获取用户信息然后展示出来。下面看看如何对这个Action进行测试。

public class UserController : Controller
{
private readonly IUserService _userService;
public UserController(IUserService userService)
{
_userService = userService;
}
public IActionResult UserInfo(string userId)
{
if (string.IsNullOrEmpty(userId))
{
throw new ArgumentNullException(nameof(userId));
}
var user = _userService.Get(userId);
return View(user);
}
}

测试代码：

[TestMethod()]
public void UserInfoTest()
{
var userService = new Mock<IUserService>();
userService.Setup(s => s.Get(It.IsAny<string>())).Returns(new User());
var ctrl = new UserController(userService.Object);
//对空参数进行assert
Assert.ThrowsException<ArgumentNullException>(() => {
var result = ctrl.UserInfo(null);
});
//对空参数进行assert
Assert.ThrowsException<ArgumentNullException>(() => {
var result = ctrl.UserInfo("");
});
var result = ctrl.UserInfo("1");
Assert.IsNotNull(result);
Assert.IsInstanceOfType(result, typeof(ViewResult));
}

我们对一个Action进行测试主要的思路就是模拟各种入参，使测试代码能够到达所有的分支，并且Assert输出是否为空，是否为指定的类型等。

对ViewModel进行测试

我们编写Action的时候还会涉及ViewModel给视图传递数据，这部分也需要进行测试。修改测试用例，加入对ViewModel的测试代码：

[TestMethod()]
public void UserInfoTest()
{
var userService = new Mock<IUserService>();
userService.Setup(s => s.Get(It.IsAny<string>())).Returns(new User()
{
Id = "x"
}) ;
var ctrl = new UserController(userService.Object);
Assert.ThrowsException<ArgumentNullException>(() => {
var result = ctrl.UserInfo(null);
});
Assert.ThrowsException<ArgumentNullException>(() => {
var result = ctrl.UserInfo("");
});
var result = ctrl.UserInfo("1");
Assert.IsNotNull(result);
Assert.IsInstanceOfType(result, typeof(ViewResult));
//对viewModel进行assert
var vr = result as ViewResult;
Assert.IsNotNull(vr.Model);
Assert.IsInstanceOfType(vr.Model, typeof(User));
var user = vr.Model as User;
Assert.AreEqual("x", user.Id);
}

对ViewData进行测试

我们编写Action的时候还会涉及ViewData给视图传递数据，这部分同样需要测试。修改Action代码，对ViewData进行赋值：

public IActionResult UserInfo(string userId)
{
if (string.IsNullOrEmpty(userId))
{
throw new ArgumentNullException(nameof(userId));
}
var user = _userService.Get(userId);
ViewData["title"] = "user_info";
return View(user);
}

修改测试用例，加入对ViewData的测试代码：

[TestMethod()]
public void UserInfoTest()
{
var userService = new Mock<IUserService>();
userService.Setup(s => s.Get(It.IsAny<string>())).Returns(new User()
{
Id = "x"
}) ;
var ctrl = new UserController(userService.Object);
Assert.ThrowsException<ArgumentNullException>(() => {
var result = ctrl.UserInfo(null);
});
Assert.ThrowsException<ArgumentNullException>(() => {
var result = ctrl.UserInfo("");
});
var result = ctrl.UserInfo("1");
Assert.IsNotNull(result);
Assert.IsInstanceOfType(result, typeof(ViewResult));
var vr = result as ViewResult;
Assert.IsNotNull(vr.Model);
Assert.IsInstanceOfType(vr.Model, typeof(User));
var user = vr.Model as User;
Assert.AreEqual("x", user.Id);
//对viewData进行assert
Assert.IsTrue(vr.ViewData.ContainsKey("title"));
var title = vr.ViewData["title"];
Assert.AreEqual("user_info", title);
}

对ViewBag进行测试

因为ViewBag事实上是ViewData的dynamic类型的包装，所以Action代码不用改，可以直接对ViewBag进行测试：

[TestMethod()]
public void UserInfoTest()
{
var userService = new Mock<IUserService>();
userService.Setup(s => s.Get(It.IsAny<string>())).Returns(new User()
{
Id = "x"
}) ;
var ctrl = new UserController(userService.Object);
Assert.ThrowsException<ArgumentNullException>(() => {
var result = ctrl.UserInfo(null);
});
Assert.ThrowsException<ArgumentNullException>(() => {
var result = ctrl.UserInfo("");
});
var result = ctrl.UserInfo("1");
Assert.IsNotNull(result);
Assert.IsInstanceOfType(result, typeof(ViewResult));
var vr = result as ViewResult;
Assert.IsNotNull(vr.Model);
Assert.IsInstanceOfType(vr.Model, typeof(User));
var user = vr.Model as User;
Assert.AreEqual("x", user.Id);
Assert.IsTrue(vr.ViewData.ContainsKey("title"));
var title = vr.ViewData["title"];
Assert.AreEqual("user_info", title);
//对viewBag进行assert
string title1 = ctrl.ViewBag.title;
Assert.AreEqual("user_info", title1);
}

设置HttpContext

我们编写Action的时候很多时候需要调用基类里的HttpContext，比如获取Request对象，获取Path，获取Headers等等，所以有的时候需要自己实例化HttpContext以进行测试。

    var ctrl = new AccountController();    ctrl.ControllerContext = new ControllerContext();    ctrl.ControllerContext.HttpContext = new DefaultHttpContext();

对HttpContext.SignInAsync进行mock

我们使用ASP.NET Core框架进行登录认证的时候，往往使用HttpContext.SignInAsync进行认证授权，所以单元测试的时候也需要进行mock。下面是一个典型的登录Action，对密码进行认证后调用SignInAsync在客户端生成登录凭证，否则跳到登录失败页面。

public async Task<IActionResult> Login(string password)
{
if (password == "123")
{
var claims = new List<Claim>
{
new Claim("UserName","x")
};
var authProperties = new AuthenticationProperties
{
};
var claimsIdentity = new ClaimsIdentity(
claims, CookieAuthenticationDefaults.AuthenticationScheme);
await HttpContext.SignInAsync(
CookieAuthenticationDefaults.AuthenticationScheme,
new ClaimsPrincipal(claimsIdentity),
authProperties);
return Redirect("login_success");
}
return Redirect("login_fail");
}

HttpContext.SignInAsync其实个时扩展方法，SignInAsync其实最终是调用了IAuthenticationService里的SignInAsync方法。所以我们需要mock的就是IAuthenticationService接口，否者代码走到HttpContext.SignInAsync会提示找不到IAuthenticationService的service。而IAuthenticationService本身是通过IServiceProvider注入到程序里的，所以同时需要mock接口IServiceProvider。

[TestMethod()]
public async Task LoginTest()
{
var ctrl = new AccountController();
var authenticationService = new Mock<IAuthenticationService>();
var sp = new Mock<IServiceProvider>();
sp.Setup(s => s.GetService(typeof(IAuthenticationService)))
.Returns(() => {
return authenticationService.Object;
});
ctrl.ControllerContext = new ControllerContext();
ctrl.ControllerContext.HttpContext = new DefaultHttpContext();
ctrl.ControllerContext.HttpContext.RequestServices = sp.Object;
var result = await ctrl.Login("123");
Assert.IsNotNull(result);
Assert.IsInstanceOfType(result, typeof(RedirectResult));
var rr = result as RedirectResult;
Assert.AreEqual("login_success", rr.Url);
result = await ctrl.Login("1");
Assert.IsNotNull(result);
Assert.IsInstanceOfType(result, typeof(RedirectResult));
rr = result as RedirectResult;
Assert.AreEqual("login_fail", rr.Url);
}

对HttpContext.AuthenticateAsync进行mock

HttpContext.AuthenticateAsync同样比较常用。这个扩展方法同样是在IAuthenticationService里，所以测试代码跟上面的SignInAsync类似，只是需要对AuthenticateAsync继续mock返回值success or fail。

public async Task<IActionResult> Login()
{
if ((await HttpContext.AuthenticateAsync()).Succeeded)
{
return Redirect("/home");
}
return Redirect("/login");
}

测试用例：

[TestMethod()]
public async Task LoginTest1()
{
var authenticationService = new Mock<IAuthenticationService>();
//设置AuthenticateAsync为success
authenticationService.Setup(s => s.AuthenticateAsync(It.IsAny<HttpContext>(), It.IsAny<string>()))
.ReturnsAsync(AuthenticateResult.Success(new AuthenticationTicket(new System.Security.Claims.ClaimsPrincipal(), "")));
var sp = new Mock<IServiceProvider>();
sp.Setup(s => s.GetService(typeof(IAuthenticationService)))
.Returns(() => {
return authenticationService.Object;
});
var ctrl = new AccountController();
ctrl.ControllerContext = new ControllerContext();
ctrl.ControllerContext.HttpContext = new DefaultHttpContext();
ctrl.ControllerContext.HttpContext.RequestServices = sp.Object;
var act = await ctrl.Login();
Assert.IsNotNull(act);
Assert.IsInstanceOfType(act, typeof(RedirectResult));
var rd = act as RedirectResult;
Assert.AreEqual("/home", rd.Url);
//设置AuthenticateAsync为fail
authenticationService.Setup(s => s.AuthenticateAsync(It.IsAny<HttpContext>(), It.IsAny<string>()))
.ReturnsAsync(AuthenticateResult.Fail(""));
act = await ctrl.Login();
Assert.IsNotNull(act);
Assert.IsInstanceOfType(act, typeof(RedirectResult));
rd = act as RedirectResult;
Assert.AreEqual("/login", rd.Url);
}

Filter进行测试

我们写Controller的时候往往需要配合很多Filter使用，所以Filter的测试也很重要。下面演示下如何对Fitler进行测试。

public class MyFilter: ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext context)
{
if (context.HttpContext.Request.Path.Value.Contains("/abc/"))
{
context.Result = new ContentResult() {
Content = "拒绝访问"
};
}
base.OnActionExecuting(context);
}
}

对Filter的测试最主要的是模拟ActionExecutingContext参数，以及其中的HttpContext等，然后对预期进行Assert。

[TestMethod()]
public void OnActionExecutingTest()
{
var filter = new MyFilter();
var actContext = new ActionContext(new DefaultHttpContext(),new RouteData(), new ActionDescriptor());
actContext.HttpContext.Request.Path = "/abc/123";
var listFilters = new List<IFilterMetadata>();
var argDict = new Dictionary<string, object>();
var actExContext = new ActionExecutingContext(
actContext ,
listFilters ,
argDict ,
new AccountController()
);
filter.OnActionExecuting(actExContext);
Assert.IsNotNull(actExContext.Result);
Assert.IsInstanceOfType(actExContext.Result, typeof(ContentResult));
var cr = actExContext.Result as ContentResult;
Assert.AreEqual("拒绝访问", cr.Content);
actContext = new ActionContext(new DefaultHttpContext(), new RouteData(), new ActionDescriptor());
actContext.HttpContext.Request.Path = "/1/123";
listFilters = new List<IFilterMetadata>();
argDict = new Dictionary<string, object>();
actExContext = new ActionExecutingContext(
actContext,
listFilters,
argDict,
new AccountController()
);
filter.OnActionExecuting(actExContext);
Assert.IsNull(actExContext.Result);
}

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原文地址：https://blog.51cto.com/u_15127577/2729017