尝试为 ASP.Net Core 3.1 单元测试创​​建 Mock.Of<ControllerContext>() 时出错

Question

根据定义 here 的 Moq Quickstart 的最后一部分，我正在尝试配置以下 Mock 以便将 Form 值传递给被测控制器方法：

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<> 行上失败并出现以下错误：

System.NotSupportedException：不支持的表达式：mock => mock.HttpContext

不可覆盖的成员（此处为：ActionContext.get_HttpContext）不得用于设置/验证表达式。

我错过了什么？我的做法与快速入门文档中定义的示例不同吗？

Answer 1

错误是因为ControllerContext.HttpContext 属性不是virtual，所以 Moq 无法覆盖它。

考虑使用实际的ControllerContext 并模拟HttpContext 来分配给属性

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;

//...