c# - 如何模拟 HttpContext 以访问 IIdentity 的扩展方法？

Question

在我的 MVC 项目中，我正在为 Controller 构建单元测试以返回 View 。

这个controller的action结果构建了一个viewmodel，这个viewmodel的constructor调用

HttpContext.Current.User.Identity.NameWithoutDomain().ToUpper();

其中NameWithoutDomain是IIdentity的扩展方法。

每当我运行它时，我总是收到“找不到对象”的消息，我很好奇如何适本地模拟它以进行单元测试？

扩展方法:

public static class SystemWebExtension
{
    public static string NameWithoutDomain(this IIdentity identity)
    {
        return identity.Name.Split('\\').Last();
    }
}

模型构造函数:

public Model()
{
    this.PreparedByUser = HttpContext.Current.User.Identity.NameWithoutDomain().ToUpper();
    this.AuthorizedBy = true;
    this.AuthorizedByUser = HttpContext.Current.User.Identity.NameWithoutDomain().ToUpper();
    this.IssueCredit = true;
    this.CreateUser = string.IsNullOrEmpty(this.CreateUser) ? Environment.UserName.ToLower() : this.CreateUser;
    this.CreateDate = this.CreateDate.HasValue ? this.CreateDate : DateTime.Now;
    this.UpdateUser = string.IsNullOrEmpty(this.CreateUser) ? null : Environment.UserName.ToLower();
    this.UpdateDate = this.CreateDate.HasValue ? DateTime.Now : (DateTime?) null;
}

Answer 1

避免与 HttpContext 耦合，因为它在单元测试时不可用。

您应该明确地将必要的值注入(inject)模型

public Model(IIdentity identity) {
    this.PreparedByUser = identity.NameWithoutDomain().ToUpper();
    this.AuthorizedBy = true;
    this.AuthorizedByUser = identity.NameWithoutDomain().ToUpper();
    this.IssueCredit = true;
    this.CreateUser = string.IsNullOrEmpty(this.CreateUser) ? Environment.UserName.ToLower() : this.CreateUser;
    this.CreateDate = this.CreateDate.HasValue ? this.CreateDate : DateTime.Now;
    this.UpdateUser = string.IsNullOrEmpty(this.CreateUser) ? null : Environment.UserName.ToLower();
    this.UpdateDate = this.CreateDate.HasValue ? DateTime.Now : (DateTime?) null;
}

由于使用了 Controller ，您可以访问其属性中的所需信息

//...

var model = new Model(this.User.Identity);

return View(model);

并且在测试时，您可以通过其 Controller 上下文配置 Controller

//...
var username = "some username here"
var identity = new GenericIdentity(username, "");
identity.AddClaim(new Claim(ClaimTypes.Name, username));
var principal = new GenericPrincipal(identity, roles: new string[] { });
var user = new ClaimsPrincipal(principal);

var context = new Mock<HttpContextBase>();
context.Setup(_ => _.User).Returns(user);

//...

controller.ControllerContext = new ControllerContext(context.Object, new RouteData(),  controller );