我试图在。NET核心环境中用NUnit和Moq测试下面的方法:

[HttpGet]
public async Task<IActionResult> DeviceType()
{
    string deviceIp = HttpContext.GetServerVariable("REMOTE_ADDR");
    var result = await DeviceService.GetTypeForAsync(deviceIp);
    return Ok(result);
}

问题是模拟一个HttpContext.GetServerVariable。我已经尝试用ControllerContext模拟上下文并插入它:

var actionContext = new Mock<ActionContext>();
var httpContext = new Mock<HttpContext>();
httpContext.Setup(x => x.GetServerVariable(It.IsAny<string>())).Returns("192.168.1.1");
actionContext.Setup(x => x.HttpContext).Returns(httpContext.Object);
//...
var deviceController = new DeviceController();
deviceController.ControllerContext = new ControllerContext(actionContext.Object);

但测试未通过并引发错误:

System.NotSupportedException:不支持表达式:x=>；X.GetServerVariable（It.IsAny（））扩展方法（此处:HttpContextServerVariableExtensions.GetServerVariable）不能在安装/验证表达式中使用。

问题是:如何模拟httpContext.getServerVariable（“remote_addr”）？