Fixes #3692++ - Rearchitects drivers (#3837)

UnitTests/ConsoleDrivers/V2/WindowSizeMonitorTests.cs

@@ -0,0 +1,76 @@
+using Moq;
+
+namespace UnitTests.ConsoleDrivers.V2;
+public class WindowSizeMonitorTests
+{
+    [Fact]
+    public void TestWindowSizeMonitor_RaisesEventWhenChanges ()
+    {
+        var consoleOutput = new Mock<IConsoleOutput> ();
+
+        var queue = new Queue<Size>(new []{
+            new Size (30, 20),
+            new Size (20, 20)
+
+        });
+
+        consoleOutput.Setup (m => m.GetWindowSize ())
+                     .Returns (queue.Dequeue);
+
+        var outputBuffer = Mock.Of<IOutputBuffer> ();
+
+        var monitor = new WindowSizeMonitor (consoleOutput.Object, outputBuffer);
+
+        var result = new List<SizeChangedEventArgs> ();
+        monitor.SizeChanging += (s, e) => { result.Add (e);};
+
+        Assert.Empty (result);
+        monitor.Poll ();
+
+        Assert.Single (result);
+        Assert.Equal (new Size (30,20),result [0].Size);
+
+        monitor.Poll ();
+
+        Assert.Equal (2,result.Count);
+        Assert.Equal (new Size (30, 20), result [0].Size);
+        Assert.Equal (new Size (20, 20), result [1].Size);
+    }
+
+    [Fact]
+    public void TestWindowSizeMonitor_DoesNotRaiseEventWhen_NoChanges ()
+    {
+        var consoleOutput = new Mock<IConsoleOutput> ();
+
+        var queue = new Queue<Size> (new []{
+            new Size (30, 20),
+            new Size (30, 20),
+        });
+
+        consoleOutput.Setup (m => m.GetWindowSize ())
+                     .Returns (queue.Dequeue);
+
+        var outputBuffer = Mock.Of<IOutputBuffer> ();
+
+        var monitor = new WindowSizeMonitor (consoleOutput.Object, outputBuffer);
+
+        var result = new List<SizeChangedEventArgs> ();
+        monitor.SizeChanging += (s, e) => { result.Add (e); };
+
+        // First poll always raises event because going from unknown size i.e. 0,0
+        Assert.Empty (result);
+        monitor.Poll ();
+
+        Assert.Single (result);
+        Assert.Equal (new Size (30, 20), result [0].Size);
+
+        // No change 
+        monitor.Poll ();
+
+        Assert.Single (result);
+        Assert.Equal (new Size (30, 20), result [0].Size);
+    }
+
+
+
+}