c# - 尝试为 ASP.Net Core 3.1 单元测试创​​建 Mock.Of() 时出错

Question

根据 Moq 快速入门的最后一部分定义 here ，我正在尝试配置以下 Mock，以便将 Form 值传递给被测 Controller 方法:

var formCollection = new FormCollection(
                new System.Collections.Generic.Dictionary<string, Microsoft.Extensions.Primitives.StringValues>()
            {
                    {"mAction", "someAction" },
                    {"mRefId", "0" }
            });

        var controllerContext = Mock.Of<ControllerContext>(ctx =>
            ctx.HttpContext.Request.Form == formCollection);
        
        controller.ControllerContext = controllerContext;

但是，当运行测试时，它在 Mock.Of<> 上失败了。出现以下错误的行:

System.NotSupportedException : Unsupported expression: mock => mock.HttpContext

Non-overridable members (here: ActionContext.get_HttpContext) may not be used in setup / verification expressions.

我错过了什么？我是否按照 Quickstart 文档中定义的示例进行操作？

Answer 1

错误是因为 ControllerContext.HttpContext 属性不是 virtual ，因此 Moq 无法覆盖它。
考虑使用实际 ControllerContext 并 mock HttpContext分配给属性(property)

var formCollection = new FormCollection(new Dictionary<string, StringValues>()
    {
        {"mAction", "someAction" },
        {"mRefId", "0" }
    });

var controllerContext = new ControllerContext() {
    HttpContext = Mock.Of<HttpContext>(ctx => ctx.Request.Form == formCollection)
};

controller.ControllerContext = controllerContext;

//...

甚至使用 DefaultHttpContext并分配所需的值

var formCollection = new FormCollection(new Dictionary<string, StringValues>()
    {
        {"mAction", "someAction" },
        {"mRefId", "0" }
    });

HttpContext httpContext = new DefaultHttpContext();
httpContext.Request.Form = formCollection;

var controllerContext = new ControllerContext() {
    HttpContext = httpContext
};

controller.ControllerContext = controllerContext;

//...