Treat unused variable warnings as errors (and fix)

These are all compiler level 3 warnings.

Author: andyleejordan

.editorconfig

@@ -13,6 +13,14 @@ trim_trailing_whitespace = true
 csharp_space_before_open_square_brackets = true
 csharp_space_after_keywords_in_control_flow_statements = true
 
+# CS0168: The variable 'var' is declared but never used
+dotnet_diagnostic.CS0168.severity = error
+# CS0169: The private field 'class member' is never used
+dotnet_diagnostic.CS0169.severity = error
+# CS0219: The variable 'variable' is assigned but its value is never used
+dotnet_diagnostic.CS0219.severity = error
+# CS0414: The private field 'field' is assigned but its value is never used
+dotnet_diagnostic.CS0414.severity = error
 # CA2007: Do not directly await a Task
 dotnet_diagnostic.CA2007.severity = error
 # CA1822: Mark members as static

src/PowerShellEditorServices/Services/DebugAdapter/DebugService.cs

@@ -43,8 +43,6 @@ internal class DebugService
         private StackFrameDetails[] stackFrameDetails;
         private readonly PropertyInfo invocationTypeScriptPositionProperty;
 
-        private static int breakpointHitCounter;
-
         private readonly SemaphoreSlim debugInfoHandle = AsyncUtils.CreateSimpleLockingSemaphore();
         #endregion
 

test/PowerShellEditorServices.Test.E2E/LanguageServerProtocolMessageTests.cs

@@ -35,8 +35,6 @@ public class LanguageServerProtocolMessageTests : IClassFixture<LSPTestsFixture>
         private readonly static string s_binDir =
             Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
 
-        private static bool s_registeredOnLogMessage;
-
         private readonly ILanguageClient PsesLanguageClient;
         private readonly List<Diagnostic> Diagnostics;
         private readonly List<PsesTelemetryEvent> TelemetryEvents;