1 files changed, 72 insertions, 0 deletions
diff --git a/Xamarin.Forms.Xaml.UnitTests/ConstraintExpression.xaml.cs b/Xamarin.Forms.Xaml.UnitTests/ConstraintExpression.xaml.cs
new file mode 100644
index 00000000..3786ccb5
--- /dev/null
+++ b/Xamarin.Forms.Xaml.UnitTests/ConstraintExpression.xaml.cs
@@ -0,0 +1,72 @@
+using System;
+using System.Collections.Generic;
+
+using Xamarin.Forms;
+using Xamarin.Forms.Core.UnitTests;
+
+using NUnit.Framework;
+
+namespace Xamarin.Forms.Xaml.UnitTests
+{
+	public partial class ConstraintExpression : ContentPage
+	{
+		public ConstraintExpression ()
+		{
+			InitializeComponent ();
+		}
+
+		public ConstraintExpression (bool useCompiledXaml)
+		{
+			//this stub will be replaced at compile time
+		}
+
+		[TestFixture]
+		public class Tests
+		{
+			[SetUp]
+			public void Setup ()
+			{
+				Device.PlatformServices = new MockPlatformServices ();
+			}
+
+			[TestCase (false)]
+			[TestCase (true)]
+			public void ConstantConstraint (bool useCompiledXaml)
+			{
+				var layout = new ConstraintExpression (useCompiledXaml);
+				var label = layout.constantConstraint;
+				var constraint = RelativeLayout.GetWidthConstraint (label);
+				Assert.NotNull (constraint);
+				Assert.AreEqual (42, constraint.Compute (null));
+			}
+
+			[TestCase (false)]
+			[TestCase (true)]
+			public void ConstraintRelativeToParent (bool useCompiledXaml)
+			{
+				var layout = new ConstraintExpression (useCompiledXaml);
+				layout.relativeLayout.Layout (new Rectangle (0, 0, 200, 200));
+				var label = layout.constraintRelativeToParent;
+				var constraint = RelativeLayout.GetWidthConstraint (label);
+				Assert.NotNull (constraint);
+				Assert.AreEqual (102, constraint.Compute (layout.relativeLayout));
+			}
+
+			[TestCase (false)]
+			[TestCase (true)]
+			public void ContraintRelativeToView (bool useCompiledXaml)
+			{
+				var layout = new ConstraintExpression (useCompiledXaml) { 
+					IsPlatformEnabled = true
+				};
+				layout.relativeLayout.Layout (new Rectangle (0, 0, 200, 100));
+				layout.foo.Layout (new Rectangle (5, 5, 190, 25));
+
+				var label = layout.constraintRelativeToView;
+				var constraint = RelativeLayout.GetWidthConstraint (label);
+				Assert.NotNull (constraint);
+				Assert.AreEqual (97, constraint.Compute (layout.relativeLayout));
+			}
+		}
+	}
+}
+\ No newline at end of file