Partially Addresses #2616. Support combining sequences that don't normalize (#2932)

* Fixes #2616. Support combining sequences that don't normalize

* Decouples Application from ConsoleDriver in TestHelpers

* Updates driver tests to match new arch

* Start on making all driver tests test all drivers

* Improves handling if combining marks.

* Fix unit tests fails.

* Fix unit tests fails.

* Handling combining mask.

* Tying to fix this unit test that sometimes fail.

* Add support for combining mask on NetDriver.

* Enable CombiningMarks as List<Rune>.

* Prevents combining marks on invalid runes default and space.

* Formatting for CI tests.

* Fix non-normalized combining mark to add 1 to Col.

* Reformatting for retest the CI.

* Forces non-normalized CMs to be ignored.

---------

Co-authored-by: Tig <tig@users.noreply.github.com>

UnitTests/Application/ApplicationTests.cs

@@ -422,20 +422,25 @@ public class ApplicationTests {
 
 	#region ShutdownTests
 	[Fact]
-	public void Shutdown_Allows_Async ()
+	public async void Shutdown_Allows_Async ()
 	{
-		static async Task TaskWithAsyncContinuation ()
+		bool isCompletedSuccessfully = false;
+
+		async Task TaskWithAsyncContinuation ()
 		{
 			await Task.Yield ();
 			await Task.Yield ();
+
+			isCompletedSuccessfully = true;
 		}
 
 		Init ();
 		Application.Shutdown ();
 
-		var task = TaskWithAsyncContinuation ();
+		Assert.False (isCompletedSuccessfully);
+		await TaskWithAsyncContinuation ();
 		Thread.Sleep (100);
-		Assert.True (task.IsCompletedSuccessfully);
+		Assert.True (isCompletedSuccessfully);
 	}
 
 	[Fact]

UnitTests/ConsoleDrivers/AddRuneTests.cs

@@ -1,4 +1,5 @@
-using System.Buffers;
+using System;
+using System.Buffers;
 using System.Text;
 using Xunit;
 using Xunit.Abstractions;
@@ -11,29 +12,33 @@ public class AddRuneTests {
 
 	public AddRuneTests (ITestOutputHelper output)
 	{
+		ConsoleDriver.RunningUnitTests = true;
 		this._output = output;
 	}
 
-	[Fact]
-	public void AddRune ()
+	[Theory]
+	[InlineData (typeof (FakeDriver))]
+	[InlineData (typeof (NetDriver))]
+	[InlineData (typeof (CursesDriver))]
+	[InlineData (typeof (WindowsDriver))]
+	public void AddRune (Type driverType)
 	{
-
-		var driver = new FakeDriver ();
-		Application.Init (driver);
+		var driver = (ConsoleDriver)Activator.CreateInstance (driverType);
 		driver.Init ();
 
+		driver.Rows = 25;
+		driver.Cols = 80;
+		driver.Init ();
 		driver.AddRune (new Rune ('a'));
 		Assert.Equal ((Rune)'a', driver.Contents [0, 0].Rune);
 
 		driver.End ();
-		Application.Shutdown ();
 	}
 
 	[Fact]
 	public void AddRune_InvalidLocation_DoesNothing ()
 	{
 		var driver = new FakeDriver ();
-		Application.Init (driver);
 		driver.Init ();
 
 		driver.Move (driver.Cols, driver.Rows);
@@ -46,14 +51,12 @@ public class AddRuneTests {
 		}
 
 		driver.End ();
-		Application.Shutdown ();
 	}
 
 	[Fact]
 	public void AddRune_MovesToNextColumn ()
 	{
 		var driver = new FakeDriver ();
-		Application.Init (driver);
 		driver.Init ();
 
 		driver.AddRune ('a');
@@ -87,14 +90,12 @@ public class AddRuneTests {
 		}
 
 		driver.End ();
-		Application.Shutdown ();
 	}
 
 	[Fact]
 	public void AddRune_MovesToNextColumn_Wide ()
 	{
 		var driver = new FakeDriver ();
-		Application.Init (driver);
 		driver.Init ();
 
 		// 🍕 Slice of Pizza "\U0001F355"
@@ -134,15 +135,12 @@ public class AddRuneTests {
 		//}
 
 		driver.End ();
-		Application.Shutdown ();
 	}
 
-
 	[Fact]
 	public void AddRune_Accented_Letter_With_Three_Combining_Unicode_Chars ()
 	{
 		var driver = new FakeDriver ();
-		Application.Init (driver);
 		driver.Init ();
 
 		var expected = new Rune ('ắ');
@@ -189,6 +187,5 @@ public class AddRuneTests {
 		//		TestHelpers.AssertDriverContentsWithFrameAre (@"
 		//ắ", output);
 		driver.End ();
-		Application.Shutdown ();
 	}
 }

UnitTests/ConsoleDrivers/ConsoleDriverTests.cs

@@ -20,53 +20,33 @@ namespace Terminal.Gui.DriverTests {
 
 		[Theory]
 		[InlineData (typeof (FakeDriver))]
-		//[InlineData (typeof (NetDriver))]
-		//[InlineData (typeof (CursesDriver))]
-		//[InlineData (typeof (WindowsDriver))]
+		[InlineData (typeof (NetDriver))]
+		[InlineData (typeof (CursesDriver))]
+		[InlineData (typeof (WindowsDriver))]
 		public void Init_Inits (Type driverType)
 		{
 			var driver = (ConsoleDriver)Activator.CreateInstance (driverType);
-			Application.Init (driver);
-			driver.Init ();
+			var ml = driver.Init ();
+			Assert.NotNull (ml);
+			Assert.NotNull (driver.Clipboard);
+			Console.ForegroundColor = ConsoleColor.Red;
+			Assert.Equal (ConsoleColor.Red, Console.ForegroundColor);
+			Console.BackgroundColor = ConsoleColor.Green;
+			Assert.Equal (ConsoleColor.Green, Console.BackgroundColor);
 
-			Assert.Equal (80, Console.BufferWidth);
-			Assert.Equal (25, Console.BufferHeight);
-
-			// MockDriver is always 80x25
-			Assert.Equal (Console.BufferWidth, driver.Cols);
-			Assert.Equal (Console.BufferHeight, driver.Rows);
 			driver.End ();
-
-			// Shutdown must be called to safely clean up Application if Init has been called
-			Application.Shutdown ();
 		}
 
 		[Theory]
 		[InlineData (typeof (FakeDriver))]
-		//[InlineData (typeof (NetDriver))]
-		//[InlineData (typeof (CursesDriver))]
-		//[InlineData (typeof (WindowsDriver))]
+		[InlineData (typeof (NetDriver))]
+		[InlineData (typeof (CursesDriver))]
+		[InlineData (typeof (WindowsDriver))]
 		public void End_Cleans_Up (Type driverType)
 		{
 			var driver = (ConsoleDriver)Activator.CreateInstance (driverType);
-			Application.Init (driver);
 			driver.Init ();
-
-			Console.ForegroundColor = ConsoleColor.Red;
-			Assert.Equal (ConsoleColor.Red, Console.ForegroundColor);
-
-			Console.BackgroundColor = ConsoleColor.Green;
-			Assert.Equal (ConsoleColor.Green, Console.BackgroundColor);
-			driver.Move (2, 3);
-
 			driver.End ();
-			Assert.Equal (0, Console.CursorLeft);
-			Assert.Equal (0, Console.CursorTop);
-			Assert.Equal (ConsoleColor.Gray, Console.ForegroundColor);
-			Assert.Equal (ConsoleColor.Black, Console.BackgroundColor);
-
-			// Shutdown must be called to safely clean up Application if Init has been called
-			Application.Shutdown ();
 		}
 
 		[Theory]
@@ -199,88 +179,89 @@ namespace Terminal.Gui.DriverTests {
 		
 		[Theory]
 		[InlineData (typeof (FakeDriver))]
+		[InlineData (typeof (NetDriver))]
+		[InlineData (typeof (CursesDriver))]
+		[InlineData (typeof (WindowsDriver))]
 		public void TerminalResized_Simulation (Type driverType)
 		{
-			var driver = (FakeDriver)Activator.CreateInstance (driverType);
-			Application.Init (driver);
+			var driver = (ConsoleDriver)Activator.CreateInstance (driverType);
+			driver?.Init ();
+			driver.Cols = 80;
+			driver.Rows = 25;
+			
 			var wasTerminalResized = false;
-			Application.SizeChanging += (s, e) => {
+			driver.SizeChanged += (s, e) => {
 				wasTerminalResized = true;
 				Assert.Equal (120, e.Size.Width);
 				Assert.Equal (40, e.Size.Height);
 			};
 
-			Assert.Equal (80, Console.BufferWidth);
-			Assert.Equal (25, Console.BufferHeight);
-
-			// MockDriver is by default 80x25
-			Assert.Equal (Console.BufferWidth, driver.Cols);
-			Assert.Equal (Console.BufferHeight, driver.Rows);
+			Assert.Equal (80, driver.Cols);
+			Assert.Equal (25, driver.Rows);
 			Assert.False (wasTerminalResized);
 
-			// MockDriver will now be sets to 120x40
-			driver.SetBufferSize (120, 40);
-			Assert.Equal (120, Application.Driver.Cols);
-			Assert.Equal (40, Application.Driver.Rows);
+			driver.Cols = 120;
+			driver.Rows = 40;
+			driver.OnSizeChanged (new SizeChangedEventArgs(new Size(driver.Cols, driver.Rows)));
+			Assert.Equal (120, driver.Cols);
+			Assert.Equal (40, driver.Rows);
 			Assert.True (wasTerminalResized);
-
-
-			Application.Shutdown ();
+			driver.End ();
 		}
 
 		// Disabled due to test error - Change Task.Delay to an await
-//		[Fact, AutoInitShutdown]
-//		public void Write_Do_Not_Change_On_ProcessKey ()
-//		{
-//			var win = new Window ();
-//			Application.Begin (win);
-//			((FakeDriver)Application.Driver).SetBufferSize (20, 8);
+		//		[Fact, AutoInitShutdown]
+		//		public void Write_Do_Not_Change_On_ProcessKey ()
+		//		{
+		//			var win = new Window ();
+		//			Application.Begin (win);
+		//			((FakeDriver)Application.Driver).SetBufferSize (20, 8);
 
-//			System.Threading.Tasks.Task.Run (() => {
-//				System.Threading.Tasks.Task.Delay (500).Wait ();
-//				Application.Invoke (() => {
-//					var lbl = new Label ("Hello World") { X = Pos.Center () };
-//					var dlg = new Dialog ();
-//					dlg.Add (lbl);
-//					Application.Begin (dlg);
+		//			System.Threading.Tasks.Task.Run (() => {
+		//				System.Threading.Tasks.Task.Delay (500).Wait ();
+		//				Application.Invoke (() => {
+		//					var lbl = new Label ("Hello World") { X = Pos.Center () };
+		//					var dlg = new Dialog ();
+		//					dlg.Add (lbl);
+		//					Application.Begin (dlg);
 
-//					var expected = @"
-//┌──────────────────┐
-//│┌───────────────┐ │
-//││  Hello World  │ │
-//││               │ │
-//││               │ │
-//││               │ │
-//│└───────────────┘ │
-//└──────────────────┘
-//";
+		//					var expected = @"
+		//┌──────────────────┐
+		//│┌───────────────┐ │
+		//││  Hello World  │ │
+		//││               │ │
+		//││               │ │
+		//││               │ │
+		//│└───────────────┘ │
+		//└──────────────────┘
+		//";
 
-//					var pos = TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
-//					Assert.Equal (new Rect (0, 0, 20, 8), pos);
+		//					var pos = TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
+		//					Assert.Equal (new Rect (0, 0, 20, 8), pos);
 
-//					Assert.True (dlg.ProcessKey (new KeyEvent (Key.Tab, new KeyModifiers ())));
-//					dlg.Draw ();
+		//					Assert.True (dlg.ProcessKey (new KeyEvent (Key.Tab, new KeyModifiers ())));
+		//					dlg.Draw ();
 
-//					expected = @"
-//┌──────────────────┐
-//│┌───────────────┐ │
-//││  Hello World  │ │
-//││               │ │
-//││               │ │
-//││               │ │
-//│└───────────────┘ │
-//└──────────────────┘
-//";
+		//					expected = @"
+		//┌──────────────────┐
+		//│┌───────────────┐ │
+		//││  Hello World  │ │
+		//││               │ │
+		//││               │ │
+		//││               │ │
+		//│└───────────────┘ │
+		//└──────────────────┘
+		//";
 
-//					pos = TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
-//					Assert.Equal (new Rect (0, 0, 20, 8), pos);
+		//					pos = TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
+		//					Assert.Equal (new Rect (0, 0, 20, 8), pos);
 
-//					win.RequestStop ();
-//				});
-//			});
+		//					win.RequestStop ();
+		//				});
+		//			});
 
-//			Application.Run (win);
-//			Application.Shutdown ();
-//		}
+		//			Application.Run (win);
+		//			Application.Shutdown ();
+		//		}
 	}
 }

UnitTests/ConsoleDrivers/ContentsTests.cs

@@ -2,6 +2,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -14,54 +15,90 @@ public class ContentsTests {
 
 	public ContentsTests (ITestOutputHelper output)
 	{
+		ConsoleDriver.RunningUnitTests = true;
 		this.output = output;
 	}
 
+
+	[Theory]
+	[InlineData (typeof (FakeDriver))]
+	[InlineData (typeof (NetDriver))]
+	//[InlineData (typeof (CursesDriver))] // TODO: Uncomment when #2796 and #2615 are fixed
+	//[InlineData (typeof (WindowsDriver))] // TODO: Uncomment when #2610 is fixed
+	public void AddStr_Combining_Character_1st_Column (Type driverType)
+	{
+		var driver = (ConsoleDriver)Activator.CreateInstance (driverType);
+		driver.Init ();
+		var expected = "\u0301!";
+		driver.AddStr ("\u0301!"); // acute accent + exclamation mark
+		TestHelpers.AssertDriverContentsAre (expected, output, driver);
+
+		driver.End ();
+	}
+
 	[Theory]
 	[InlineData (typeof (FakeDriver))]
-	//[InlineData (typeof (NetDriver))]
-	//[InlineData (typeof (CursesDriver))]
-	//[InlineData (typeof (WindowsDriver))]
+	[InlineData (typeof (NetDriver))]
+	//[InlineData (typeof (CursesDriver))] // TODO: Uncomment when #2796 and #2615 are fixed
+	//[InlineData (typeof (WindowsDriver))] // TODO: Uncomment when #2610 is fixed
 	public void AddStr_With_Combining_Characters (Type driverType)
 	{
 		var driver = (ConsoleDriver)Activator.CreateInstance (driverType);
-		Application.Init (driver);
-		// driver.Init (null);
+		driver.Init ();
 
 		var acuteaccent = new System.Text.Rune (0x0301); // Combining acute accent (é)
 		var combined = "e" + acuteaccent;
 		var expected = "é";
 
 		driver.AddStr (combined);
-		TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
-
-#if false // Disabled Until #2616 is fixed
+		TestHelpers.AssertDriverContentsAre (expected, output, driver);
 
 		// 3 char combine
-		// a + ogonek + acute = <U+0061, U+0328, U+0301> ( ǫ́ )
+		// a + ogonek + acute = <U+0061, U+0328, U+0301> ( ą́ )
 		var ogonek = new System.Text.Rune (0x0328); // Combining ogonek (a small hook or comma shape)
 		combined = "a" + ogonek + acuteaccent;
-		expected = "ǫ́";
+		expected = ("a" + ogonek).Normalize(NormalizationForm.FormC); // See Issue #2616
 
 		driver.Move (0, 0);
 		driver.AddStr (combined);
-		TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
+		TestHelpers.AssertDriverContentsAre (expected, output, driver);
 
-#endif
-		
-		// Shutdown must be called to safely clean up Application if Init has been called
-		Application.Shutdown ();
+		// e + ogonek + acute = <U+0061, U+0328, U+0301> ( ę́́ )
+		combined = "e" + ogonek + acuteaccent;
+		expected = ("e" + ogonek).Normalize (NormalizationForm.FormC); // See Issue #2616
+
+		driver.Move (0, 0);
+		driver.AddStr (combined);
+		TestHelpers.AssertDriverContentsAre (expected, output, driver);
+
+		// i + ogonek + acute = <U+0061, U+0328, U+0301> ( į́́́ )
+		combined = "i" + ogonek + acuteaccent;
+		expected = ("i" + ogonek).Normalize (NormalizationForm.FormC); // See Issue #2616
+
+		driver.Move (0, 0);
+		driver.AddStr (combined);
+		TestHelpers.AssertDriverContentsAre (expected, output, driver);
+
+		// u + ogonek + acute = <U+0061, U+0328, U+0301> ( ų́́́́ )
+		combined = "u" + ogonek + acuteaccent;
+		expected = ("u" + ogonek).Normalize (NormalizationForm.FormC); // See Issue #2616
+
+		driver.Move (0, 0);
+		driver.AddStr (combined);
+		TestHelpers.AssertDriverContentsAre (expected, output, driver);
+
+		driver.End ();
 	}
 
 	[Theory]
 	[InlineData (typeof (FakeDriver))]
-	//[InlineData (typeof (NetDriver))]
-	//[InlineData (typeof (CursesDriver))]
-	//[InlineData (typeof (WindowsDriver))]
+	[InlineData (typeof (NetDriver))]
+	[InlineData (typeof (CursesDriver))]
+	[InlineData (typeof (WindowsDriver))]
 	public void Move_Bad_Coordinates (Type driverType)
 	{
 		var driver = (ConsoleDriver)Activator.CreateInstance (driverType);
-		Application.Init (driver);
+		driver.Init ();
 
 		Assert.Equal (0, driver.Col);
 		Assert.Equal (0, driver.Row);
@@ -85,13 +122,11 @@ public class ContentsTests {
 		driver.Move (500, 500);
 		Assert.Equal (500, driver.Col);
 		Assert.Equal (500, driver.Row);
-
-		// Shutdown must be called to safely clean up Application if Init has been called
-		Application.Shutdown ();
+		driver.End ();
 	}
 
 	// TODO: Add these unit tests
-	
+
 	// AddRune moves correctly
 
 	// AddRune with wide characters are handled correctly

UnitTests/ConsoleDrivers/DriverColorTests.cs

@@ -19,7 +19,7 @@ namespace Terminal.Gui.DriverTests {
 		public void SetColors_Changes_Colors (Type driverType)
 		{
 			var driver = (ConsoleDriver)Activator.CreateInstance (driverType);
-			Application.Init (driver);
+			driver.Init ();
 
 			Assert.Equal (ConsoleColor.Gray, Console.ForegroundColor);
 			Assert.Equal (ConsoleColor.Black, Console.BackgroundColor);
@@ -34,8 +34,7 @@ namespace Terminal.Gui.DriverTests {
 			Assert.Equal (ConsoleColor.Gray, Console.ForegroundColor);
 			Assert.Equal (ConsoleColor.Black, Console.BackgroundColor);
 
-			// Shutdown must be called to safely clean up Application if Init has been called
-			Application.Shutdown ();
+			driver.End ();
 		}
 
 
@@ -52,9 +51,6 @@ namespace Terminal.Gui.DriverTests {
 			Assert.Equal (expectedSetting, driver.SupportsTrueColor);
 
 			driver.End ();
-
-			// Shutdown must be called to safely clean up Application if Init has been called
-			Application.Shutdown ();
 		}
 
 		[Theory]
@@ -71,9 +67,6 @@ namespace Terminal.Gui.DriverTests {
 			Assert.True (driver.Force16Colors);
 
 			driver.End ();
-
-			// Shutdown must be called to safely clean up Application if Init has been called
-			Application.Shutdown ();
 		}
 	}
 }

UnitTests/Drawing/AttributeTests.cs

@@ -90,7 +90,6 @@ public class AttributeTests {
 	public void Constuctors_Constuct ()
 	{
 		var driver = new FakeDriver ();
-		Application.Init (driver);
 		driver.Init ();
 
 		// Test parameterless constructor
@@ -127,7 +126,6 @@ public class AttributeTests {
 		Assert.Equal (bg, attr.Background);
 
 		driver.End ();
-		Application.Shutdown ();
 	}
 
 	[Fact]
@@ -196,7 +194,6 @@ public class AttributeTests {
 	public void Implicit_Assign ()
 	{
 		var driver = new FakeDriver ();
-		Application.Init (driver);
 		driver.Init ();
 
 		var attr = new Attribute ();
@@ -216,7 +213,6 @@ public class AttributeTests {
 		Assert.Equal (value, attr.PlatformColor);
 
 		driver.End ();
-		Application.Shutdown ();
 	}
 
 	[Fact]
@@ -237,7 +233,6 @@ public class AttributeTests {
 	public void Make_Creates ()
 	{
 		var driver = new FakeDriver ();
-		Application.Init (driver);
 		driver.Init ();
 
 		var fg = new Color ();
@@ -252,7 +247,6 @@ public class AttributeTests {
 		Assert.Equal (bg, attr.Background);
 
 		driver.End ();
-		Application.Shutdown ();
 	}
 
 	[Fact]

UnitTests/FileServices/FileDialogTests.cs

@@ -401,7 +401,7 @@ namespace Terminal.Gui.FileServicesTests {
 │{CM.Glyphs.LeftBracket} ►► {CM.Glyphs.RightBracket} Enter Search                                   {CM.Glyphs.LeftBracket} OK {CM.Glyphs.RightBracket} {CM.Glyphs.LeftBracket} Cancel {CM.Glyphs.RightBracket}  │
 └─────────────────────────────────────────────────────────────────────────┘
 ";
-			TestHelpers.AssertDriverContentsAre (expected, output, true);
+			TestHelpers.AssertDriverContentsAre (expected, output, ignoreLeadingWhitespace: true);
 		}
 
 		[Fact, AutoInitShutdown]
@@ -437,7 +437,7 @@ namespace Terminal.Gui.FileServicesTests {
 │{CM.Glyphs.LeftBracket} ►► {CM.Glyphs.RightBracket} Enter Search                                   {CM.Glyphs.LeftBracket} OK {CM.Glyphs.RightBracket} {CM.Glyphs.LeftBracket} Cancel {CM.Glyphs.RightBracket}  │
 └─────────────────────────────────────────────────────────────────────────┘
 ";
-			TestHelpers.AssertDriverContentsAre (expected, output, true);
+			TestHelpers.AssertDriverContentsAre (expected, output, ignoreLeadingWhitespace: true);
 		}
 
 

UnitTests/TestHelpers.cs

@@ -147,18 +147,24 @@ partial class TestHelpers {
 	private static partial Regex LeadingWhitespaceRegEx ();
 
 #pragma warning disable xUnit1013 // Public method should be marked as test
-	public static void AssertDriverContentsAre (string expectedLook, ITestOutputHelper output, bool ignoreLeadingWhitespace = false)
+	/// <summary>
+	/// Asserts that the driver contents match the expected contents, optionally ignoring any trailing whitespace.
+	/// </summary>
+	/// <param name="expectedLook"></param>
+	/// <param name="output"></param>
+	/// <param name="driver">The ConsoleDriver to use. If null <see cref="Application.Driver"/> will be used.</param>
+	/// <param name="ignoreLeadingWhitespace"></param>
+	public static void AssertDriverContentsAre (string expectedLook, ITestOutputHelper output, ConsoleDriver driver = null, bool ignoreLeadingWhitespace = false)
 	{
 #pragma warning restore xUnit1013 // Public method should be marked as test
 
 		var sb = new StringBuilder ();
-		var driver = (FakeDriver)Application.Driver;
+		driver ??= Application.Driver;
 
 		var contents = driver.Contents;
 
 		for (int r = 0; r < driver.Rows; r++) {
 			for (int c = 0; c < driver.Cols; c++) {
-				// TODO: Remove hard-coded [0] once combining pairs is supported
 				Rune rune = contents [r, c].Rune;
 				if (rune.DecodeSurrogatePair (out char [] spair)) {
 					sb.Append (spair);
@@ -168,6 +174,10 @@ partial class TestHelpers {
 				if (rune.GetColumns () > 1) {
 					c++;
 				}
+				// See Issue #2616
+				//foreach (var combMark in contents [r, c].CombiningMarks) {
+				//	sb.Append ((char)combMark.Value);
+				//}
 			}
 			sb.AppendLine ();
 		}
@@ -198,11 +208,18 @@ partial class TestHelpers {
 		Assert.Equal (expectedLook, actualLook);
 	}
 
-	public static Rect AssertDriverContentsWithFrameAre (string expectedLook, ITestOutputHelper output)
+	/// <summary>
+	/// Asserts that the driver contents are equal to the expected look, and that the cursor is at the expected position.
+	/// </summary>
+	/// <param name="expectedLook"></param>
+	/// <param name="output"></param>
+	/// <param name="driver">The ConsoleDriver to use. If null <see cref="Application.Driver"/> will be used.</param>
+	/// <returns></returns>
+	public static Rect AssertDriverContentsWithFrameAre (string expectedLook, ITestOutputHelper output, ConsoleDriver driver = null)
 	{
 		var lines = new List<List<Rune>> ();
 		var sb = new StringBuilder ();
-		var driver = Application.Driver;
+		driver ??= Application.Driver;
 		var x = -1;
 		var y = -1;
 		var w = -1;
@@ -213,7 +230,6 @@ partial class TestHelpers {
 		for (var r = 0; r < driver.Rows; r++) {
 			var runes = new List<Rune> ();
 			for (var c = 0; c < driver.Cols; c++) {
-				// TODO: Remove hard-coded [0] once combining pairs is supported
 				Rune rune = contents [r, c].Rune;
 				if (rune != (Rune)' ') {
 					if (x == -1) {
@@ -232,6 +248,10 @@ partial class TestHelpers {
 					h = r - y + 1;
 				}
 				if (x > -1) runes.Add (rune);
+				// See Issue #2616
+				//foreach (var combMark in contents [r, c].CombiningMarks) {
+				//	runes.Add (combMark);
+				//}
 			}
 			if (runes.Count > 0) lines.Add (runes);
 		}
@@ -290,15 +310,16 @@ partial class TestHelpers {
 	/// test method will verify those colors were used in the row/col of the console during rendering
 	/// </summary>
 	/// <param name="expectedLook">Numbers between 0 and 9 for each row/col of the console.  Must be valid indexes of <paramref name="expectedColors"/></param>
+	/// <param name="driver">The ConsoleDriver to use. If null <see cref="Application.Driver"/> will be used.</param>
 	/// <param name="expectedColors"></param>
-	public static void AssertDriverColorsAre (string expectedLook, params Attribute [] expectedColors)
+	public static void AssertDriverColorsAre (string expectedLook, ConsoleDriver driver = null, params Attribute [] expectedColors)
 	{
 #pragma warning restore xUnit1013 // Public method should be marked as test
 
 		if (expectedColors.Length > 10) throw new ArgumentException ("This method only works for UIs that use at most 10 colors");
 
 		expectedLook = expectedLook.Trim ();
-		var driver = (FakeDriver)Application.Driver;
+		driver ??= Application.Driver;
 
 		var contents = driver.Contents;
 
@@ -331,11 +352,11 @@ partial class TestHelpers {
 	/// If one or more of the expected colors are not used then the failure will output both
 	/// the colors that were found to be used and which of your expectations was not met.
 	/// </summary>
+	/// <param name="driver">if null uses <see cref="Application.Driver"/></param>
 	/// <param name="expectedColors"></param>
-	internal static void AssertDriverUsedColors (params Attribute [] expectedColors)
+	internal static void AssertDriverUsedColors (ConsoleDriver driver = null, params Attribute [] expectedColors)
 	{
-		var driver = (FakeDriver)Application.Driver;
-
+		driver ??= Application.Driver;
 		var contents = driver.Contents;
 
 		var toFind = expectedColors.ToList ();

UnitTests/View/DrawTests.cs

@@ -58,7 +58,7 @@ namespace Terminal.Gui.ViewsTests {
 0020000000
 0000000000
 0111000000
-0000000000", expectedColors);
+0000000000", driver: Application.Driver, expectedColors);
 		}
 
 		[Fact, AutoInitShutdown]
@@ -106,7 +106,7 @@ namespace Terminal.Gui.ViewsTests {
 0022000000
 0000000000
 0111000000
-0000000000", expectedColors);
+0000000000", driver: Application.Driver, expectedColors);
 		}
 
 		[Fact, AutoInitShutdown]
@@ -147,7 +147,7 @@ t     ", output);
 0
 0
 0
-0", new Attribute [] { Colors.Base.Normal });
+0", driver: Application.Driver, new Attribute [] { Colors.Base.Normal });
 		}
 
 		[Fact, AutoInitShutdown]

UnitTests/View/ViewTests.cs

@@ -942,11 +942,11 @@ cccccccccccccccccccc", output);
 			if (label) {
 				TestHelpers.AssertDriverColorsAre (@"
 111111111111111111110
-111111111111111111110", attributes);
+111111111111111111110", driver: Application.Driver, attributes);
 			} else {
 				TestHelpers.AssertDriverColorsAre (@"
 222222222222222222220
-111111111111111111110", attributes);
+111111111111111111110", driver: Application.Driver, attributes);
 			}
 
 			if (label) {
@@ -958,7 +958,7 @@ cccccccccccccccccccc", output);
 				Application.Refresh ();
 				TestHelpers.AssertDriverColorsAre (@"
 222222222222222222220
-111111111111111111110", attributes);
+111111111111111111110", driver: Application.Driver, attributes);
 			}
 			Application.End (runState);
 		}

UnitTests/Views/ComboBoxTests.cs

@@ -836,7 +836,7 @@ Three ", output);
 000000
 222222
 222222
-222222", attributes);
+222222", driver: Application.Driver, attributes);
 
 			Assert.True (cb.Subviews [1].ProcessKey (new KeyEvent (Key.CursorDown, new KeyModifiers ())));
 			Assert.Equal ("", selected);
@@ -848,7 +848,7 @@ Three ", output);
 000000
 222222
 000002
-222222", attributes);
+222222", driver: Application.Driver, attributes);
 
 			Assert.True (cb.Subviews [1].ProcessKey (new KeyEvent (Key.CursorDown, new KeyModifiers ())));
 			Assert.Equal ("", selected);
@@ -860,7 +860,7 @@ Three ", output);
 000000
 222222
 222222
-000002", attributes);
+000002", driver: Application.Driver, attributes);
 
 			Assert.True (cb.Subviews [1].ProcessKey (new KeyEvent (Key.Enter, new KeyModifiers ())));
 			Assert.Equal ("Three", selected);
@@ -878,7 +878,7 @@ Three ", output);
 000000
 222222
 222222
-000002", attributes);
+000002", driver: Application.Driver, attributes);
 
 			Assert.True (cb.Subviews [1].ProcessKey (new KeyEvent (Key.CursorUp, new KeyModifiers ())));
 			Assert.Equal ("Three", selected);
@@ -890,7 +890,7 @@ Three ", output);
 000000
 222222
 000002
-111112", attributes);
+111112", driver: Application.Driver, attributes);
 
 			Assert.True (cb.Subviews [1].ProcessKey (new KeyEvent (Key.CursorUp, new KeyModifiers ())));
 			Assert.Equal ("Three", selected);
@@ -902,7 +902,7 @@ Three ", output);
 000000
 000002
 222222
-111112", attributes);
+111112", driver: Application.Driver, attributes);
 
 			Assert.True (cb.ProcessKey (new KeyEvent (Key.F4, new KeyModifiers ())));
 			Assert.Equal ("Three", selected);

UnitTests/Views/MenuTests.cs

@@ -1589,7 +1589,7 @@ Edit
 	    };
 
 			TestHelpers.AssertDriverColorsAre (@"
-00000000000000", attributes);
+00000000000000", driver: Application.Driver, attributes);
 
 			Assert.True (menu.MouseEvent (new MouseEvent {
 				X = 0,
@@ -1605,7 +1605,7 @@ Edit
 02222222222220
 00000000000000
 00000000000000
-00000000000000", attributes);
+00000000000000", driver: Application.Driver, attributes);
 
 			Assert.True (top.Subviews [1].MouseEvent (new MouseEvent {
 				X = 0,
@@ -1621,7 +1621,7 @@ Edit
 02222222222220
 00000000000000
 00000000000000
-00000000000000", attributes);
+00000000000000", driver: Application.Driver, attributes);
 
 			Assert.True (top.Subviews [1].MouseEvent (new MouseEvent {
 				X = 0,
@@ -1637,7 +1637,7 @@ Edit
 02222222222220
 00000000000000
 00000000000000
-00000000000000", attributes);
+00000000000000", driver: Application.Driver, attributes);
 		}
 
 		[Fact, AutoInitShutdown]

UnitTests/Views/RuneCellTests.cs

@@ -116,12 +116,12 @@ Error   ";
 2222220000
 3333000000
 4444400000";
-			TestHelpers.AssertDriverColorsAre (expectedColor, attributes);
+			TestHelpers.AssertDriverColorsAre (expectedColor, driver: Application.Driver, attributes);
 
 			tv.WordWrap = true;
 			Application.Refresh ();
 			TestHelpers.AssertDriverContentsWithFrameAre (expectedText, _output);
-			TestHelpers.AssertDriverColorsAre (expectedColor, attributes);
+			TestHelpers.AssertDriverColorsAre (expectedColor, driver: Application.Driver, attributes);
 
 			tv.CursorPosition = new Point (6, 2);
 			tv.SelectionStartColumn = 0;
@@ -149,7 +149,7 @@ Dialogror ";
 4444444444
 4444000000
 4444444440";
-			TestHelpers.AssertDriverColorsAre (expectedColor, attributes);
+			TestHelpers.AssertDriverColorsAre (expectedColor, driver: Application.Driver, attributes);
 
 			tv.Undo ();
 			tv.CursorPosition = new Point (0, 3);
@@ -180,7 +180,7 @@ ror       ";
 4444000000
 4444440000
 4440000000";
-			TestHelpers.AssertDriverColorsAre (expectedColor, attributes);
+			TestHelpers.AssertDriverColorsAre (expectedColor, driver: Application.Driver, attributes);
 
 			Application.End (rs);
 		}

UnitTests/Views/TableViewTests.cs

@@ -836,7 +836,7 @@ namespace Terminal.Gui.ViewsTests {
 01000
 ";
 
-			TestHelpers.AssertDriverColorsAre (expectedColors, new Attribute [] {
+			TestHelpers.AssertDriverColorsAre (expectedColors, driver: Application.Driver, new Attribute [] {
 				// 0
 				tv.ColorScheme.Normal,				
 				// 1
@@ -883,7 +883,7 @@ namespace Terminal.Gui.ViewsTests {
 			var invertFocus = new Attribute (tv.ColorScheme.Focus.Background, tv.ColorScheme.Focus.Foreground);
 			var invertHotNormal = new Attribute (tv.ColorScheme.HotNormal.Background, tv.ColorScheme.HotNormal.Foreground);
 
-			TestHelpers.AssertDriverColorsAre (expectedColors, new Attribute [] {
+			TestHelpers.AssertDriverColorsAre (expectedColors, driver: Application.Driver, new Attribute [] {
 				// 0
 				tv.ColorScheme.Normal,				
 				// 1
@@ -938,7 +938,7 @@ namespace Terminal.Gui.ViewsTests {
 21222
 ";
 
-			TestHelpers.AssertDriverColorsAre (expectedColors, new Attribute [] {
+			TestHelpers.AssertDriverColorsAre (expectedColors, driver: Application.Driver, new Attribute [] {
 				// 0
 				tv.ColorScheme.Normal,				
 				// 1
@@ -971,7 +971,7 @@ namespace Terminal.Gui.ViewsTests {
 			// now we only see 2 colors used (the selected cell color and Normal
 			// rowHighlight should no longer be used because the delegate returned null
 			// (now that the cell value is 5 - which does not match the conditional)
-			TestHelpers.AssertDriverColorsAre (expectedColors, new Attribute [] {
+			TestHelpers.AssertDriverColorsAre (expectedColors, driver: Application.Driver, new Attribute [] {
 				// 0
 				tv.ColorScheme.Normal,
 				// 1
@@ -1030,7 +1030,7 @@ namespace Terminal.Gui.ViewsTests {
 01020
 ";
 
-			TestHelpers.AssertDriverColorsAre (expectedColors, new Attribute [] {
+			TestHelpers.AssertDriverColorsAre (expectedColors, driver: Application.Driver, new Attribute [] {
 				// 0
 				tv.ColorScheme.Normal,				
 				// 1
@@ -1063,7 +1063,7 @@ namespace Terminal.Gui.ViewsTests {
 			// now we only see 2 colors used (the selected cell color and Normal
 			// cellHighlight should no longer be used because the delegate returned null
 			// (now that the cell value is 5 - which does not match the conditional)
-			TestHelpers.AssertDriverColorsAre (expectedColors, new Attribute [] {
+			TestHelpers.AssertDriverColorsAre (expectedColors, driver: Application.Driver, new Attribute [] {
 				// 0
 				tv.ColorScheme.Normal,				
 				// 1
@@ -2113,7 +2113,7 @@ namespace Terminal.Gui.ViewsTests {
 00000000000000000000
 01111101101111111110
 ";
-			TestHelpers.AssertDriverColorsAre (expected, new Attribute [] { tv.ColorScheme.Normal, color });
+			TestHelpers.AssertDriverColorsAre (expected, driver: Application.Driver, new Attribute [] { tv.ColorScheme.Normal, color });
 
 		}
 
@@ -2233,7 +2233,7 @@ namespace Terminal.Gui.ViewsTests {
 0111110
 0000000";
 
-			TestHelpers.AssertDriverColorsAre (expected, normal, focus);
+			TestHelpers.AssertDriverColorsAre (expected, driver: Application.Driver, normal, focus);
 		}
 
 		[Fact, AutoInitShutdown]
@@ -2290,7 +2290,7 @@ namespace Terminal.Gui.ViewsTests {
 0101010
 0000000";
 
-			TestHelpers.AssertDriverColorsAre (expected, normal, focus);
+			TestHelpers.AssertDriverColorsAre (expected, driver: Application.Driver, normal, focus);
 		}
 
 		[Fact, AutoInitShutdown]
@@ -2785,7 +2785,7 @@ A B C
 000000
 111111";
 
-			TestHelpers.AssertDriverColorsAre (expected, normal, focus);
+			TestHelpers.AssertDriverColorsAre (expected, driver: Application.Driver, normal, focus);
 		}
 
 		public static DataTableSource BuildTable (int cols, int rows)

UnitTests/Views/TreeViewTests.cs

@@ -858,19 +858,19 @@ namespace Terminal.Gui.ViewsTests {
 
 
 			// Normal drawing of the tree view
-			TestHelpers.AssertDriverContentsAre (
-@"├-normal
+			TestHelpers.AssertDriverContentsAre (@"
+├-normal
 │ ├─pink
 │ └─normal
 └─pink
 ", output);
 			// Should all be the same color
-			TestHelpers.AssertDriverColorsAre (
-@"00000000
+			TestHelpers.AssertDriverColorsAre (@"
+00000000
 00000000
 0000000000
 000000
-",
+", driver: Application.Driver,
 				new [] { tv.ColorScheme.Normal, pink });
 
 			var pinkScheme = new ColorScheme {
@@ -887,20 +887,20 @@ namespace Terminal.Gui.ViewsTests {
 			tv.Draw ();
 
 			// Same text
-			TestHelpers.AssertDriverContentsAre (
-@"├-normal
+			TestHelpers.AssertDriverContentsAre (@"
+├-normal
 │ ├─pink
 │ └─normal
 └─pink
 ", output);
 			// but now the item (only not lines) appear
 			// in pink when they are the word "pink"
-			TestHelpers.AssertDriverColorsAre (
-@"00000000
+			TestHelpers.AssertDriverColorsAre (@"
+00000000
 00001111
 0000000000
 001111
-",
+", driver: Application.Driver,
 				new [] { tv.ColorScheme.Normal, pink });
 		}