added exists matcher

src/Unicorn.UI.Core/Matchers/ControlMatchers.cs

@@ -42,6 +42,13 @@ public ControlEnabledMatcher Enabled() =>
         public ControlVisibleMatcher Visible() =>
             new ControlVisibleMatcher();
 
+        /// <summary>
+        /// Matcher to check if UI control exists (Works only for PageObject described controls!).
+        /// </summary>
+        /// <returns><see cref="ControlExistsMatcher"/> instance</returns>
+        public ControlExistsMatcher ExistsInPageObject() =>
+            new ControlExistsMatcher();
+
         /// <summary>
         /// Matcher to check if <see cref="ISelectable"/> UI control is selected.
         /// </summary>

src/Unicorn.UI.Core/Matchers/IControlMatchers/ControlExistsMatcher.cs

@@ -0,0 +1,42 @@
+using Unicorn.Taf.Core.Verification.Matchers;
+using Unicorn.UI.Core.Controls;
+using Unicorn.UI.Core.PageObject;
+
+namespace Unicorn.UI.Core.Matchers.IControlMatchers
+{
+    /// <summary>
+    /// Matcher to check if UI control exists.
+    /// </summary>
+    public class ControlExistsMatcher : TypeSafeMatcher<IControl>
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ControlExistsMatcher"/> class.
+        /// </summary>
+        public ControlExistsMatcher()
+        {
+        }
+
+        /// <summary>
+        /// Gets check description.
+        /// </summary>
+        public override string CheckDescription => "exists";
+
+        /// <summary>
+        /// Checks if UI control exists.
+        /// </summary>
+        /// <param name="actual">UI control under check</param>
+        /// <returns>true - if control exists; otherwise - false</returns>
+        public override bool Matches(IControl actual)
+        {
+            if (actual == null)
+            {
+                DescribeMismatch("null");
+                return Reverse;
+            }
+
+            bool exists = actual.ExistsInPageObject();
+            DescribeMismatch(exists ? "exists" : "does not exist");
+            return exists;
+        }
+    }
+}

src/Unicorn.UnitTests/FakeControls/HasValueControl.cs

@@ -0,0 +1,9 @@
+using Unicorn.UI.Core.Controls.Interfaces;
+
+namespace Unicorn.UnitTests.FakeControls
+{
+    class HasValueControl : IHasValue
+    {
+        public string Value => "some actual value";
+    }
+}

src/Unicorn.UnitTests/Tests/MatchersTests.cs

@@ -10,12 +10,14 @@ namespace Unicorn.UnitTests.Tests
     internal class MatchersTests
     {
         private HasTitleControl iHasTitle;
+        private HasValueControl iHasValue;
         private HasItemsControl iHasItems;
 
         [BeforeSuite]
         public void SetUp()
         {
             iHasTitle = new HasTitleControl();
+            iHasValue = new HasValueControl();
             iHasItems = new HasItemsControl();
         }
 
@@ -41,6 +43,28 @@ public void HasTitleTestNegative() =>
 
         #endregion
 
+        #region HasValue
+
+        [Test]
+        public void HasValueReverseTestNegative() =>
+            Assert.Throws<AssertionException>(() =>
+                Assert.That(iHasValue, Is.Not(Ui.Control.HasValue("some actual value"))));
+
+        [Test]
+        public void HasValueTestPositive() =>
+            Assert.That(iHasValue, Ui.Control.HasValue("some actual value"));
+
+        [Test]
+        public void HasValueReverseTestPositive() =>
+            Assert.That(iHasValue, Is.Not(Ui.Control.HasValue("sofe actual value")));
+
+        [Test]
+        public void HasValueTestNegative() =>
+            Assert.Throws<AssertionException>(() =>
+                Assert.That(iHasValue, Ui.Control.HasValue("some atual value")));
+
+        #endregion
+
         #region HasItems
 
         [Test]