how to unit test accountcontroller -nunit test(help) this is mvc accountcontroller

How do I unit test this?-Nunit. ??? thanks - this is accountcontroller of MVC, I want to unit test please help with code

public class AccountController : Controller { private ApplicationSignInManager _signInManager; private ApplicationUserManager _userManager;

    public AccountController()
    {
    }

    public AccountController(ApplicationUserManager userManager, ApplicationSignInManager signInManager )
    {
        UserManager = userManager;
        SignInManager = signInManager;
    }

    public ApplicationSignInManager SignInManager
    {
        get
        {
            return _signInManager ?? HttpContext.GetOwinContext().Get<ApplicationSignInManager>();
        }
        private set 
        { 
            _signInManager = value; 
        }
    }

    public ApplicationUserManager UserManager
    {
        get
        {
            return _userManager ?? HttpContext.GetOwinContext().GetUserManager<ApplicationUserManager>();
        }
        private set
        {
            _userManager = value;
        }
    }

    //
    // GET: /Account/Login
    [AllowAnonymous]
    public ActionResult Login(string returnUrl)
    {
        ViewBag.ReturnUrl = returnUrl;
        return View();
    }

    //
    // POST: /Account/Login
    [HttpPost]
    [AllowAnonymous]
    [ValidateAntiForgeryToken]
    public async Task<ActionResult> Login(LoginViewModel model, string returnUrl)
    {
        if (!ModelState.IsValid)
        {
            return View(model);
        }

        // This doesn't count login failures towards account lockout
        // To enable password failures to trigger account lockout, change to shouldLockout: true
        var result = await SignInManager.PasswordSignInAsync(model.Email, model.Password, model.RememberMe, shouldLockout: false);
        switch (result)
        {
            case SignInStatus.Success:
                return RedirectToLocal(returnUrl);
            case SignInStatus.LockedOut:
                return View("Lockout");
            case SignInStatus.RequiresVerification:
                return RedirectToAction("SendCode", new { ReturnUrl = returnUrl, RememberMe = model.RememberMe });
            case SignInStatus.Failure:
            default:
                ModelState.AddModelError("", "Invalid login attempt.");
                return View(model);
        }
    }

    //
    // GET: /Account/VerifyCode
    [AllowAnonymous]
    public async Task<ActionResult> VerifyCode(string provider, string returnUrl, bool rememberMe)
    {
        // Require that the user has already logged in via username/password or external login
        if (!await SignInManager.HasBeenVerifiedAsync())
        {
            return View("Error");
        }
        return View(new VerifyCodeViewModel { Provider = provider, ReturnUrl = returnUrl, RememberMe = rememberMe });
    }

    //
    // POST: /Account/VerifyCode
    [HttpPost]
    [AllowAnonymous]
    [ValidateAntiForgeryToken]
    public async Task<ActionResult> VerifyCode(VerifyCodeViewModel model)
    {
        if (!ModelState.IsValid)
        {
            return View(model);
        }

        // The following code protects for brute force attacks against the two factor codes. 
        // If a user enters incorrect codes for a specified amount of time then the user account 
        // will be locked out for a specified amount of time. 
        // You can configure the account lockout settings in IdentityConfig
        var result = await SignInManager.TwoFactorSignInAsync(model.Provider, model.Code, isPersistent:  model.RememberMe, rememberBrowser: model.RememberBrowser);
        switch (result)
        {
            case SignInStatus.Success:
                return RedirectToLocal(model.ReturnUrl);
            case SignInStatus.LockedOut:
                return View("Lockout");
            case SignInStatus.Failure:
            default:
                ModelState.AddModelError("", "Invalid code.");
                return View(model);
        }
    }

    //
    // GET: /Account/Register
    [AllowAnonymous]
    public ActionResult Register()
    {
        return View();
    }

    //
    // POST: /Account/Register
    [HttpPost]
    [AllowAnonymous]
    [ValidateAntiForgeryToken]
    public async Task<ActionResult> Register(RegisterViewModel model)
    {
        if (ModelState.IsValid)
        {
            var user = new ApplicationUser { UserName = model.Email, Email = model.Email };
            var result = await UserManager.CreateAsync(user, model.Password);
            if (result.Succeeded)
            {
                await SignInManager.SignInAsync(user, isPersistent:false, rememberBrowser:false);

                // For more information on how to enable account confirmation and password reset please visit http://ift.tt/1vUusLV
                // Send an email with this link
                // string code = await UserManager.GenerateEmailConfirmationTokenAsync(user.Id);
                // var callbackUrl = Url.Action("ConfirmEmail", "Account", new { userId = user.Id, code = code }, protocol: Request.Url.Scheme);
                // await UserManager.SendEmailAsync(user.Id, "Confirm your account", "Please confirm your account by clicking <a href=\"" + callbackUrl + "\">here</a>");

                return RedirectToAction("Index", "Home");
            }
            AddErrors(result);
        }

        // If we got this far, something failed, redisplay form
        return View(model);
    }

    //
    // GET: /Account/ConfirmEmail
    [AllowAnonymous]
    public async Task<ActionResult> ConfirmEmail(string userId, string code)
    {
        if (userId == null || code == null)
        {
            return View("Error");
        }
        var result = await UserManager.ConfirmEmailAsync(userId, code);
        return View(result.Succeeded ? "ConfirmEmail" : "Error");
    }

    //
    // GET: /Account/ForgotPassword
    [AllowAnonymous]
    public ActionResult ForgotPassword()
    {
        return View();
    }