Add SearchCollectionNavigator

UnitTests/SearchCollectionNavigatorTests.cs

@@ -0,0 +1,126 @@
+using Terminal.Gui;
+using Xunit;
+
+namespace UnitTests {
+	public class SearchCollectionNavigatorTests {
+
+		[Fact]
+		public void TestSearchCollectionNavigator_Cycling ()
+		{
+			var s = new string []{
+    "appricot",
+    "arm",
+    "bat",
+    "batman",
+    "candle"
+  };
+
+			var n = new SearchCollectionNavigator ();
+			Assert.Equal (2, n.CalculateNewIndex (s, 0, 'b'));
+			Assert.Equal (3, n.CalculateNewIndex (s, 2, 'b'));
+
+			// if 4 (candle) is selected it should loop back to bat
+			Assert.Equal (2, n.CalculateNewIndex (s, 4, 'b'));
+
+		}
+
+
+		[Fact]
+		public void TestSearchCollectionNavigator_ToSearchText ()
+		{
+			var s = new string []{
+    "appricot",
+    "arm",
+    "bat",
+    "batman",
+    "bbfish",
+    "candle"
+  };
+
+			var n = new SearchCollectionNavigator ();
+			Assert.Equal (2, n.CalculateNewIndex (s, 0, 'b'));
+			Assert.Equal (4, n.CalculateNewIndex (s, 2, 'b'));
+
+			// another 'b' means searching for "bbb" which does not exist
+			// so we go back to looking for "b" as a fresh key strike
+			Assert.Equal (4, n.CalculateNewIndex (s, 2, 'b'));
+		}
+
+		[Fact]
+		public void TestSearchCollectionNavigator_FullText ()
+		{
+			var s = new string []{
+    "appricot",
+    "arm",
+    "ta",
+    "target",
+    "text",
+    "egg",
+    "candle"
+  };
+
+			var n = new SearchCollectionNavigator ();
+			Assert.Equal (2, n.CalculateNewIndex (s, 0, 't'));
+
+			// should match "te" in "text"
+			Assert.Equal (4, n.CalculateNewIndex (s, 2, 'e'));
+
+			// still matches text
+			Assert.Equal (4, n.CalculateNewIndex (s, 4, 'x'));
+
+			// nothing starts texa so it jumps to a for appricot
+			Assert.Equal (0, n.CalculateNewIndex (s, 4, 'a'));
+		}
+
+		[Fact]
+		public void TestSearchCollectionNavigator_Unicode ()
+		{
+			var s = new string []{
+    "appricot",
+    "arm",
+    "ta",
+    "丗丙业丞",
+    "丗丙丛",
+    "text",
+    "egg",
+    "candle"
+  };
+
+			var n = new SearchCollectionNavigator ();
+			Assert.Equal (3, n.CalculateNewIndex (s, 0, '丗'));
+
+			// 丗丙业丞 is as good a match as 丗丙丛
+			// so when doing multi character searches we should
+			// prefer to stay on the same index unless we invalidate
+			// our typed text
+			Assert.Equal (3, n.CalculateNewIndex (s, 3, '丙'));
+
+			// No longer matches 丗丙业丞 and now only matches 丗丙丛
+			// so we should move to the new match
+			Assert.Equal (4, n.CalculateNewIndex (s, 3, '丛'));
+
+			// nothing starts "丗丙丛a" so it jumps to a for appricot
+			Assert.Equal (0, n.CalculateNewIndex (s, 4, 'a'));
+		}
+
+		[Fact]
+		public void TestSearchCollectionNavigator_AtSymbol ()
+		{
+			var s = new string []{
+    "appricot",
+    "arm",
+    "ta",
+    "@bob",
+    "@bb",
+    "text",
+    "egg",
+    "candle"
+  };
+
+			var n = new SearchCollectionNavigator ();
+			Assert.Equal (3, n.CalculateNewIndex (s, 0, '@'));
+			Assert.Equal (3, n.CalculateNewIndex (s, 3, 'b'));
+			Assert.Equal (4, n.CalculateNewIndex (s, 3, 'b'));
+		}
+	}
+}