如何注入模拟程序集以与 Moq 一起使用

我的控制器中有一个方法，它将属性数据从当前执行的程序集返回到分部视图中。

在这个例子中，我只是拉动标题，但我需要用它做更多的事情。

控制器：

    var title = "";

    var asm = Assembly.GetExecutingAssembly();
    var attrs = asm.GetCustomAttributes(typeof(AssemblyTitleAttribute));
    var titleAttr = (AssemblyTitleAttribute)attributes[0];

    title = titleAttr.Title;

    return PartialView("_Build", title);

在 Moq 中编写单元测试时，我需要找到一种方法将程序集属性注入到模拟中，以便我可以验证在运行控制器测试时是否生成了正确的属性，然后使用我的断言执行 x 或 y 。

单元测试：

    //Arrange
    //The magic I need to happen.

    //Act
    var controller = GetController();
    var result = controller.MyMethod() as PartialViewResult;
    var title = result.Model;

    //Assert
    Assert.AreEqual("Title", title); //currently static, need to verify against a mock

我知道这是一组非常简单的代码，但此时我只需要概念证明。

有没有一个好的方法来创建一个假的Assembly？ 我需要使用 System.Reflection.Emit 吗？

您可以创建一个虚拟方法，例如GetCustomAttributes它提供给定类型的属性。然后在你的测试项目中testable类将从控制器类派生并重写此方法。

家庭控制器：

private IDependency _someDependency;

public HomeController(IDependency someDependency)
{
    _someDependency = someDependency;
}

public ActionResult MyMethod()
{
    var title = "";
    var version = "";

    IEnumerable<Attribute> attributes = GetCustomAttributes(typeof(AssemblyVersionAttribute)).ToList();
    AssemblyVersionAttribute verAttr = attributes.OfType<AssemblyVersionAttribute>().FirstOrDefault();
    if (verAttr != null) version = verAttr.Version;

    attributes = GetCustomAttributes(typeof(AssemblyTitleAttribute)).ToList();
    AssemblyTitleAttribute titleAttr = attributes.OfType<AssemblyTitleAttribute>().FirstOrDefault();
    if (titleAttr != null) title = titleAttr.Title;

    return PartialView("_Build", title + version);
}

public virtual IEnumerable<Attribute> GetCustomAttributes(Type attributeType)
{
    var asm = Assembly.GetExecutingAssembly();
    var attrs = asm.GetCustomAttributes(attributeType);
    return attrs;
} 

Test:

[TestClass]
public class MyMethodTest
{
    [TestMethod]
    public void MyMethod_WhenCalled_PartialViewIsReturned()
    {
        // Arrange
        // The magic I need to happen.

        Mock<IDependency> dependencyStub = new Mock<IDependency>();
        // dependencyStub.Setup(...).Returns(...);
        var controller = new TestableHomeController(dependencyStub.Object)
        {
            UseFakeAttributes = true
        };

        // Act
        var result = controller.MyMethod() as PartialViewResult;

        // Assert
        var model = result.Model;
        Assert.AreEqual("MyFakeTitle1.0.0.0", model); // currently static, need to verify against a mock
    }

    private class TestableHomeController : HomeController
    {
        public bool UseFakeAttributes { get; set; }

        public TestableHomeController(IDependency someDependency)
            :base(someDependency)
        { }

        public override IEnumerable<Attribute> GetCustomAttributes(Type attributeType)
        {
            return UseFakeAttributes
                ? new List<Attribute>
                    {
                        new AssemblyTitleAttribute("MyFakeTitle"),
                        new AssemblyVersionAttribute("1.0.0.0"),
                        new AssemblyDescriptionAttribute("Assembly fake description")
                        // next attributes ...
                    }.Where(a => a.GetType() == attributeType)
                : base.GetCustomAttributes(attributeType);
        }
    }
}