How to Unit Test a GlassController Action which Returns a View Taking a Model

I'm a sitecore developer and I want to create a sample sitecore helix unit testing project for testing out our "HomeBottomContentController" controller:

    public class HomeBottomContentController : GlassController
    {
        private readonly ISitecoreContext _iSitecoreContext;
        public HomeBottomContentController(ISitecoreContext iSitecoreContext)
        {
            _iSitecoreContext = iSitecoreContext;
        }

        public override ActionResult Index()
        {
            var model = _iSitecoreContext.GetCurrentItem<Home_Control>();
            return View("~/Views/HomeBottomContent/HomeBottomContent.cshtml", model);
        }
    }

I have created a WTW.Feature.HomeBottomContent.Tests project, for the purpose of testing this entire component using helix unit testing. In it I have a UnitTest1.cs file with following:

namespace WTW.Feature.HomeBottomContent.Tests
{
    [TestClass]
    public class UnitTest1
    {
        [TestMethod]
        public void Test_ISitecoreContextInsertion()
        {
            var iSitecoreContext = Mock.Of<Glass.Mapper.Sc.ISitecoreContext>();
            HomeBottomContentController controllerUnderTest = new HomeBottomContentController(iSitecoreContext);
            var result = controllerUnderTest.Index() as ViewResult;
            Assert.IsNotNull(result);
        }
    }
}

This test does pass, meaning "result" is NOT null; however, the problem is when I step into the Index() code, I see that the "model" variable is NULL when we do

    var model = _iSitecoreContext.GetCurrentItem<Home_Control>();

My question is, how exactly do I change this code to make sure that the "model" in that line does not become null? How do I "mock" an item in unit test code for the _iSitecoreContext so that it has a "Home_Control" template with legit values for its fields? Would that even be the right approach? Most online sources I've found do not have a similar scenario, I'm looking for the shortest code possible.

Another question I had is, how can I test the below Index() method in my [TestMethod], given that the SitecoreContext is declared inside the Index() method, rather than received in the HomeBottomContentController constructor like above? Is there a way to do that from the [TestMethod], or we have to send in the SitecoreContext into the HomeBottomContentController constructor or into the Index() method as a parameter?

public override ActionResult Index()
{
    var context = new SitecoreContext();
    var model = context.GetCurrentItem<Home_Control>();
    return View("~/Views/HomeBottomContent/HomeBottomContent.cshtml", model);
}