Add screen reader test fixture

And work around helper module's test filter.

Author: andyleejordan

test/MockConsole.cs

@@ -300,6 +300,17 @@ public virtual void BlankRestOfLine()
                 buffer[writePos + i].ForegroundColor = ForegroundColor;
             }
         }
+        
+        public virtual void BlankRestOfBuffer()
+        {
+            var writePos = CursorTop * BufferWidth + CursorLeft;
+            for (int i = 0; i < buffer.Length - writePos; i++)
+            {
+                buffer[writePos + i].UnicodeChar = ' ';
+                buffer[writePos + i].BackgroundColor = BackgroundColor;
+                buffer[writePos + i].ForegroundColor = ForegroundColor;
+            }
+        }
 
         public virtual void Clear()
         {
@@ -334,6 +345,7 @@ private static void ToggleNegative(TestConsole c, bool b)
             c.BackgroundColor = (ConsoleColor)((int)c.BackgroundColor ^ 7);
             c._negative = b;
         }
+        
         protected static readonly Dictionary<string, Action<TestConsole>> EscapeSequenceActions = new()
         {
             {"7", c => ToggleNegative(c, true) },
@@ -376,7 +388,8 @@ private static void ToggleNegative(TestConsole c, bool b)
                 c.ForegroundColor = DefaultForeground;
                 c.BackgroundColor = DefaultBackground;
             }},
-            {"2J", c => c.SetCursorPosition(0, 0) }
+            { "0J", c => c.BlankRestOfBuffer() },
+            { "2J", c => c.SetCursorPosition(0, 0) },
         };
     }
 
@@ -520,6 +533,17 @@ public override void BlankRestOfLine()
             }
         }
 
+        public override void BlankRestOfBuffer()
+        {
+            var writePos = (_offset + CursorTop) * BufferWidth + CursorLeft;
+            for (int i = 0; i < buffer.Length - writePos; i++)
+            {
+                buffer[writePos + i].UnicodeChar = ' ';
+                buffer[writePos + i].BackgroundColor = BackgroundColor;
+                buffer[writePos + i].ForegroundColor = ForegroundColor;
+            }
+        }
+
         public override void Clear()
         {
             _offset = 0;

test/UnitTestReadLine.cs

@@ -130,6 +130,7 @@ protected ReadLine(ConsoleFixture fixture, ITestOutputHelper output, string lang
         internal virtual bool KeyboardHasGreaterThan => true;
         internal virtual bool KeyboardHasCtrlRBracket => true;
         internal virtual bool KeyboardHasCtrlAt => true;
+        internal virtual bool ScreenReaderModeEnabled => false;
 
         static ReadLine()
         {
@@ -444,8 +445,13 @@ private void AssertScreenIs(int top, int lines, params object[] items)
                 // that shouldn't be and aren't ever set by any code in PSReadLine, so we'll
                 // ignore those bits and just check the stuff we do set.
                 Assert.Equal(expectedBuffer[i].UnicodeChar, consoleBuffer[i].UnicodeChar);
-                Assert.Equal(expectedBuffer[i].ForegroundColor, consoleBuffer[i].ForegroundColor);
-                Assert.Equal(expectedBuffer[i].BackgroundColor, consoleBuffer[i].BackgroundColor);
+                if (!ScreenReaderModeEnabled)
+                {
+                    // Changing colors is not supported in screen reader mode,
+                    // and this is the simplest way to disable checking that in all the tests.
+                    Assert.Equal(expectedBuffer[i].ForegroundColor, consoleBuffer[i].ForegroundColor);
+                    Assert.Equal(expectedBuffer[i].BackgroundColor, consoleBuffer[i].BackgroundColor);
+                }
             }
         }
 
@@ -582,6 +588,7 @@ private void TestSetup(TestConsole console, KeyMode keyMode, params KeyHandler[]
                 ContinuationPrompt                = PSConsoleReadLineOptions.DefaultContinuationPrompt,
                 DingDuration                      = 1,  // Make tests virtually silent when they ding
                 DingTone                          = 37, // Make tests virtually silent when they ding
+                EnableScreenReaderMode            = ScreenReaderModeEnabled,
                 ExtraPromptLineCount              = PSConsoleReadLineOptions.DefaultExtraPromptLineCount,
                 HistoryNoDuplicates               = PSConsoleReadLineOptions.DefaultHistoryNoDuplicates,
                 HistorySaveStyle                  = HistorySaveStyle.SaveNothing,
@@ -668,4 +675,14 @@ public fr_FR_Windows(ConsoleFixture fixture, ITestOutputHelper output)
         internal override bool KeyboardHasCtrlRBracket => false;
         internal override bool KeyboardHasCtrlAt => false;
     }
+    
+    public class ScreenReader : Test.ReadLine, IClassFixture<ConsoleFixture>
+    {
+        public ScreenReader(ConsoleFixture fixture, ITestOutputHelper output)
+            : base(fixture, output, "en-US", "windows")
+        {
+        }
+        
+        internal override bool ScreenReaderModeEnabled => true;
+    }
 }

tools/helper.psm1

@@ -210,7 +210,7 @@ function Start-TestRun
 
     function RunXunitTestsInNewProcess ([string] $Layout, [string] $OperatingSystem)
     {
-        $filter = "FullyQualifiedName~Test.{0}_{1}" -f ($Layout -replace '-','_'), $OperatingSystem
+        $filter = "(FullyQualifiedName~Test.{0}_{1})|(FullyQualifiedName~Test.ScreenReader)" -f ($Layout -replace '-','_'), $OperatingSystem
         $testResultFile = "xUnitTestResults.{0}.xml" -f $Layout
         $testResultFile = Join-Path $testResultFolder $testResultFile