Hide more internal PowerShell scripts from debugger

Author: andyleejordan

src/PowerShellEditorServices.Hosting/EditorServicesLoader.cs

@@ -350,7 +350,9 @@ private void LogHostInformation()
         private static string GetPSOutputEncoding()
         {
             using SMA.PowerShell pwsh = SMA.PowerShell.Create();
-            return pwsh.AddScript("$OutputEncoding.EncodingName", useLocalScope: true).Invoke<string>()[0];
+            return pwsh.AddScript(
+                "[System.Diagnostics.DebuggerHidden()]param() $OutputEncoding.EncodingName",
+                useLocalScope: true).Invoke<string>()[0];
         }
 
         // TODO: Deduplicate this with VersionUtils.

src/PowerShellEditorServices/Services/DebugAdapter/DebugService.cs

@@ -367,7 +367,7 @@ public async Task<string> SetVariableAsync(int variableContainerReferenceId, str
 
             // Evaluate the expression to get back a PowerShell object from the expression string.
             // This may throw, in which case the exception is propagated to the caller
-            PSCommand evaluateExpressionCommand = new PSCommand().AddScript(value);
+            PSCommand evaluateExpressionCommand = new PSCommand().AddScript($"[System.Diagnostics.DebuggerHidden()]param() {value}");
             IReadOnlyList<object> expressionResults = await _executionService.ExecutePSCommandAsync<object>(evaluateExpressionCommand, CancellationToken.None).ConfigureAwait(false);
             if (expressionResults.Count == 0)
             {
@@ -500,7 +500,7 @@ public async Task<VariableDetails> EvaluateExpressionAsync(
             bool writeResultAsOutput,
             CancellationToken cancellationToken)
         {
-            PSCommand command = new PSCommand().AddScript(expressionString);
+            PSCommand command = new PSCommand().AddScript($"[System.Diagnostics.DebuggerHidden()]param() {expressionString}");
             IReadOnlyList<PSObject> results;
             try
             {
@@ -799,7 +799,7 @@ private async Task FetchStackFramesAsync(string scriptNameOverride)
 
             // PSObject is used here instead of the specific type because we get deserialized
             // objects from remote sessions and want a common interface.
-            PSCommand psCommand = new PSCommand().AddScript($"[Collections.ArrayList]{callStackVarName} = @(); {getPSCallStack}; {returnSerializedIfInRemoteRunspace}");
+            PSCommand psCommand = new PSCommand().AddScript($"[System.Diagnostics.DebuggerHidden()]param() [Collections.ArrayList]{callStackVarName} = @(); {getPSCallStack}; {returnSerializedIfInRemoteRunspace}");
             IReadOnlyList<PSObject> results = await _executionService.ExecutePSCommandAsync<PSObject>(psCommand, CancellationToken.None).ConfigureAwait(false);
 
             IEnumerable callStack = isRemoteRunspace

src/PowerShellEditorServices/Services/DebugAdapter/Handlers/DebugEvaluateHandler.cs

@@ -48,7 +48,7 @@ public async Task<EvaluateResponseBody> Handle(EvaluateRequestArguments request,
             if (isFromRepl)
             {
                 await _executionService.ExecutePSCommandAsync(
-                    new PSCommand().AddScript(request.Expression),
+                    new PSCommand().AddScript($"[System.Diagnostics.DebuggerHidden()]param() {request.Expression}"),
                     cancellationToken,
                     new PowerShellExecutionOptions { WriteOutputToHost = true, ThrowOnError = false, AddToHistory = true }).HandleErrorsAsync(_logger).ConfigureAwait(false);
             }

src/PowerShellEditorServices/Services/PowerShell/Context/PowerShellVersionDetails.cs

@@ -55,7 +55,7 @@ public static PowerShellVersionDetails GetVersionDetails(ILogger logger, PowerSh
             try
             {
                 Hashtable psVersionTable = pwsh
-                    .AddScript("$PSVersionTable", useLocalScope: true)
+                    .AddScript("[System.Diagnostics.DebuggerHidden()]param() $PSVersionTable", useLocalScope: true)
                     .InvokeAndClear<Hashtable>()
                     .FirstOrDefault();
 

src/PowerShellEditorServices/Services/PowerShell/Handlers/ExpandAliasHandler.cs

@@ -33,7 +33,7 @@ public async Task<ExpandAliasResult> Handle(ExpandAliasParams request, Cancellat
         {
             const string script = @"
 function __Expand-Alias {
-
+    [System.Diagnostics.DebuggerHidden()]
     param($targetScript)
 
     [ref]$errors=$null

src/PowerShellEditorServices/Services/PowerShell/Handlers/ShowHelpHandler.cs

@@ -27,7 +27,9 @@ internal class ShowHelpHandler : IShowHelpHandler
 
         public async Task<Unit> Handle(ShowHelpParams request, CancellationToken cancellationToken)
         {
+            // TODO: Refactor to not rerun the function definition every time.
             const string CheckHelpScript = @"
+                [System.Diagnostics.DebuggerHidden()]
                 [CmdletBinding()]
                 param (
                     [String]$CommandName

src/PowerShellEditorServices/Services/PowerShell/Runspace/SessionDetails.cs

@@ -27,7 +27,7 @@ public static SessionDetails GetFromPowerShell(PowerShell pwsh)
         {
             Hashtable detailsObject = pwsh
                 .AddScript(
-                    $"@{{ '{Property_ComputerName}' = if ([Environment]::MachineName) {{[Environment]::MachineName}}  else {{'localhost'}}; '{Property_ProcessId}' = $PID; '{Property_InstanceId}' = $host.InstanceId }}",
+                    $"[System.Diagnostics.DebuggerHidden()]param() @{{ '{Property_ComputerName}' = if ([Environment]::MachineName) {{[Environment]::MachineName}} else {{'localhost'}}; '{Property_ProcessId}' = $PID; '{Property_InstanceId}' = $host.InstanceId }}",
                     useLocalScope: true)
                 .InvokeAndClear<Hashtable>()
                 .FirstOrDefault();