Add notes learned from debugging

Author: andyleejordan

PowerShellEditorServices.build.ps1

@@ -238,6 +238,10 @@ task TestServer TestServerWinPS,TestServerPS7,TestServerPS72
 
 task TestServerWinPS -If (-not $script:IsNix) {
     Set-Location .\test\PowerShellEditorServices.Test\
+    # TODO: See https://github.com/dotnet/sdk/issues/18353 for x64 test host
+    # that is debuggable! If architecture is added, the assembly path gets an
+    # additional folder, necesstiating fixes to find the commands definition
+    # file and test files.
     exec { & $script:dotnetExe $script:dotnetTestArgs $script:NetRuntime.Desktop }
 }
 

src/PowerShellEditorServices/Services/PowerShell/Host/PsesInternalHost.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation.
+// Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
 using System;
@@ -245,6 +245,11 @@ public void TriggerShutdown()
             if (Interlocked.Exchange(ref _shuttingDown, 1) == 0)
             {
                 _cancellationContext.CancelCurrentTaskStack();
+                // NOTE: This is mostly for sanity's sake, as during debugging of tests I became
+                // concerned that the repeated creation and disposal of the host was not also
+                // joining and disposing this thread, leaving the tests in a weird state. Because
+                // the tasks have been canceled, we should be able to join this thread.
+                _pipelineThread.Join();
             }
         }
 
@@ -550,6 +555,8 @@ private void RunTopLevelExecutionLoop()
                 }
                 else
                 {
+                    // TODO: Is this really necessary? The other 'RunExecutionLoop' already handles
+                    // the case where the console REPL isn't enabled.
                     RunNoPromptExecutionLoop();
                 }
             }

src/PowerShellEditorServices/Services/TextDocument/ScriptFile.cs

@@ -39,6 +39,7 @@ internal sealed class ScriptFile
         /// </summary>
         public string Id
         {
+            // TODO: Is this why the drive letter changes?
             get { return this.FilePath.ToLower(); }
         }