NavigationModelTests.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using NUnit.Framework;
using Xamarin.Forms.Internals;

namespace Xamarin.Forms.Core.UnitTests
{
	[TestFixture]
	public class NavigationModelTests : BaseTestFixture
	{
		[Test]
		public void CurrentNullWhenEmpty ()
		{
			var navModel = new NavigationModel ();
			Assert.Null (navModel.CurrentPage);
		}

		[Test]
		public void CurrentGivesLastViewWithoutModal ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();
			var page2 = new ContentPage ();

			navModel.Push (page1, null);
			navModel.Push (page2, page1);

			Assert.AreEqual (page2, navModel.CurrentPage);
		}

		[Test]
		public void CurrentGivesLastViewWithModal()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();
			var page2 = new ContentPage ();

			var modal1 = new ContentPage ();
			var modal2 = new ContentPage ();

			navModel.Push (page1, null);
			navModel.Push (page2, page1);

			navModel.PushModal (modal1);
			navModel.Push (modal2, modal1);

			Assert.AreEqual (modal2, navModel.CurrentPage);
		}

		[Test]
		public void Roots ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();
			var page2 = new ContentPage ();

			var modal1 = new ContentPage ();
			var modal2 = new ContentPage ();

			navModel.Push (page1, null);
			navModel.Push (page2, page1);

			navModel.PushModal (modal1);
			navModel.Push (modal2, modal1);

			Assert.True (navModel.Roots.SequenceEqual (new[] {page1, modal1}));
		}

		[Test]
		public void PushFirstItem ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();
			navModel.Push (page1, null);

			Assert.AreEqual (page1, navModel.CurrentPage);
			Assert.AreEqual (page1, navModel.Roots.First ());
		}

		[Test]
		public void ThrowsWhenPushingWithoutAncestor ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();
			var page2 = new ContentPage ();

			navModel.Push (page1, null);
			Assert.Throws<InvalidNavigationException> (() => navModel.Push (page2, null));
		}

		[Test]
		public void PushFromNonRootAncestor ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();
			var page2 = new ContentPage ();
			var page3 = new ContentPage ();

			page2.Parent = page1;
			page3.Parent = page2;

			navModel.Push (page1, null);
			navModel.Push (page2, page1);
			navModel.Push (page3, page2);

			Assert.AreEqual (page3, navModel.CurrentPage);
		}

		[Test]
		public void ThrowsWhenPushFromInvalidAncestor ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();
			var page2 = new ContentPage ();

			Assert.Throws<InvalidNavigationException> (() => navModel.Push (page2, page1));
		}

		[Test]
		public void Pop ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();
			var page2 = new ContentPage ();

			navModel.Push (page1, null);
			navModel.Push (page2, page1);

			navModel.Pop (page1);

			Assert.AreEqual (page1, navModel.CurrentPage);
		}

		[Test]
		public void ThrowsPoppingRootItem ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();

			navModel.Push (page1, null);

			Assert.Throws<InvalidNavigationException> (() => navModel.Pop (page1));
		}

		[Test]
		public void ThrowsPoppingRootOfModal ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();
			var page2 = new ContentPage ();

			var modal1 = new ContentPage ();

			navModel.Push (page1, null);
			navModel.Push (page2, page1);

			navModel.PushModal (modal1);
			Assert.Throws<InvalidNavigationException> (() => navModel.Pop (modal1));
		}

		[Test]
		public void ThrowsPoppingWithInvalidAncestor ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();

			navModel.Push (page1, null);

			Assert.Throws<InvalidNavigationException> (() => navModel.Pop (new ContentPage ()));
		}

		[Test]
		public void PopToRoot ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();
			var page2 = new ContentPage ();
			var page3 = new ContentPage ();

			page2.Parent = page1;
			page3.Parent = page2;

			navModel.Push (page1, null);
			navModel.Push (page2, page1);
			navModel.Push (page3, page2);

			navModel.PopToRoot (page2);

			Assert.AreEqual (page1, navModel.CurrentPage);
		}

		[Test]
		public void ThrowsWhenPopToRootOnRoot ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();

			navModel.Push (page1, null);
			Assert.Throws<InvalidNavigationException> (() => navModel.PopToRoot (page1));
		}

		[Test]
		public void ThrowsWhenPopToRootWithInvalidAncestor()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();
			var page2 = new ContentPage ();

			navModel.Push (page1, null);
			navModel.Push (page2, page1);

			Assert.Throws<InvalidNavigationException> (() => navModel.PopToRoot (new ContentPage ()));
		}

		[Test]
		public void PopModal ()
		{
			var navModel = new NavigationModel ();

			var child1 = new ContentPage ();
			var modal1 = new ContentPage ();

			navModel.Push (child1, null);
			navModel.PushModal (modal1);

			navModel.PopModal ();

			Assert.AreEqual (child1, navModel.CurrentPage);
			Assert.AreEqual (1, navModel.Roots.Count ());
		}

		[Test]
		public void ReturnsCorrectModal ()
		{
			var navModel = new NavigationModel ();

			var child1 = new ContentPage ();
			var modal1 = new ContentPage ();
			var modal2 = new ContentPage ();

			navModel.Push (child1, null);
			navModel.PushModal (modal1);
			navModel.PushModal (modal2);

			Assert.AreEqual (modal2, navModel.PopModal ());
		}

		[Test]
		public void PopTopPageWithoutModals ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();
			var page2 = new ContentPage ();

			navModel.Push (page1, null);
			navModel.Push (page2, page1);

			Assert.AreEqual (page2, navModel.PopTopPage ());
		}

		[Test]
		public void PopTopPageWithSinglePage ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();

			navModel.Push (page1, null);

			Assert.Null (navModel.PopTopPage ());
		}

		[Test]
		public void PopTopPageWithModal ()
		{
			var navModel = new NavigationModel ();

			var page1 = new ContentPage ();
			var modal1 = new ContentPage ();

			navModel.Push (page1, null);
			navModel.PushModal (modal1);

			Assert.AreEqual (modal1, navModel.PopTopPage ());
		}
	}
}