How to unit test HttpContext.SignInAsync()?

SignInAsync() Source Code

I ran into some problems with unit testing.

1. DefaultHttpContext.RequestServices is null
2. I tried to create the AuthenticationService object, but I do not know what parameters to pass

What should I do? How to unit test HttpContext.SignInAsync()?

Method under test

public async Task<IActionResult> Login(LoginViewModel vm, [FromQuery]string returnUrl)
{
    if (ModelState.IsValid)
    {
        var user = await context.Users.FirstOrDefaultAsync(u => u.UserName == vm.UserName && u.Password == vm.Password);
        if (user != null)
        {
            var claims = new List<Claim>
            {
                new Claim(ClaimTypes.Name, user.UserName)
            };
            var identity = new ClaimsIdentity(claims, "HappyDog");

            // here
            await HttpContext.SignInAsync(new ClaimsPrincipal(identity));
            return Redirect(returnUrl ?? Url.Action("Index", "Goods"));
        }
    }
    return View(vm);
}

What I have tried so far.

[TestMethod]
public async Task LoginTest()
{
    using (var context = new HappyDogContext(_happyDogOptions))
    {
        await context.Users.AddAsync(new User { Id = 1, UserName = "test", Password = "password", FacePicture = "FacePicture" });
        await context.SaveChangesAsync();

        var controller = new UserController(svc, null)
        {
            ControllerContext = new ControllerContext
            {
                HttpContext = new DefaultHttpContext
                {
                    // How mock RequestServices?
                    // RequestServices = new AuthenticationService()?
                }
            }
        };
        var vm = new LoginViewModel { UserName = "test", Password = "password" };
        var result = await controller.Login(vm, null) as RedirectResult;
        Assert.AreEqual("/Goods", result.Url);
    }
}