maui-linux/Xamarin.Forms.Core.UnitTests/EventTriggerTest.cs

using System;
using NUnit.Framework;

namespace Xamarin.Forms.Core.UnitTests
{
	internal class MockTriggerAction : TriggerAction<BindableObject>
	{
		public bool Invoked { get; set;}

		protected override void Invoke (BindableObject sender)
		{
			Invoked = true;
		}
	}

	internal class MockBindableWithEvent : VisualElement
	{
		public void FireEvent ()
		{
			if (MockEvent != null)
				MockEvent (this, EventArgs.Empty);
		}

		public void FireEvent2 ()
		{
			if (MockEvent2 != null)
				MockEvent2 (this, EventArgs.Empty);
		}

		public event EventHandler MockEvent;
		public event EventHandler MockEvent2;
	}

	[TestFixture]
	public class EventTriggerTest : BaseTestFixture
	{
		[Test]
		public void TestTriggerActionInvoked ()
		{
			var bindable = new MockBindableWithEvent ();
			var triggeraction = new MockTriggerAction ();
			var eventtrigger = new EventTrigger () { Event = "MockEvent", Actions = { triggeraction } };
			var collection = bindable.Triggers;
			collection.Add (eventtrigger);

			Assert.False (triggeraction.Invoked);
			bindable.FireEvent ();
			Assert.True (triggeraction.Invoked);
		}
			
		[Test]
		public void TestChangeEventOnEventTrigger ()
		{
			var bindable = new MockBindableWithEvent ();
			var triggeraction = new MockTriggerAction ();
			var eventtrigger = new EventTrigger  { Event = "MockEvent", Actions = { triggeraction } };
			var collection = bindable.Triggers;
			collection.Add (eventtrigger);

			triggeraction.Invoked = false;
			Assert.False (triggeraction.Invoked);
			bindable.FireEvent ();
			Assert.True (triggeraction.Invoked);

			triggeraction.Invoked = false;
			Assert.False (triggeraction.Invoked);
			bindable.FireEvent2 ();
			Assert.False (triggeraction.Invoked);

			Assert.Throws<InvalidOperationException>(()=> eventtrigger.Event = "MockEvent2");
		}
	}	
}