【茶包射手日記】PowerShell 命令列一按 $ 就噴錯

在 VSCode Terminal 執行 PowerShell 遇到奇怪問題。 [xml]$xml = Get-Content -Path sample.xml 將 XML 讀入 $xml 變數打算操作 $xml 解析內容，才按了 $ 就噴錯結束：

An error occurred while running the REPL loop:
System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at System.Text.StringBuilder.get_Chars(Int32 index)
   at Microsoft.PowerShell.PSConsoleReadLine.ConvertOffsetToPoint(Int32 offset)
   at Microsoft.PowerShell.PSConsoleReadLine.ReallyRender(RenderData renderData, String defaultColor)      
   at Microsoft.PowerShell.PSConsoleReadLine.ForceRender()
   at Microsoft.PowerShell.PSConsoleReadLine.Render()
   at Microsoft.PowerShell.PSConsoleReadLine.Insert(String s)
   at Microsoft.PowerShell.PSConsoleReadLine.ReadLine(Runspace runspace, EngineIntrinsics engineIntrinsics, CancellationToken cancellationToken, Nullable`1 lastRunStatus)
   at Microsoft.PowerShell.EditorServices.Services.PowerShell.Console.PsrlReadLine.InvokePSReadLine(CancellationToken cancellationToken) in C:\__w\1\s\src\PowerShellEditorServices\Services\PowerShell\Console\PsrlReadLine.cs:line 48
   at Microsoft.PowerShell.EditorServices.Services.PowerShell.Execution.SynchronousDelegateTask`1.Run(CancellationToken cancellationToken) in C:\__w\1\s\src\PowerShellEditorServices\Services\PowerShell\Execution\SynchronousDelegateTask.cs:line 63
   at Microsoft.PowerShell.EditorServices.Services.PowerShell.Execution.SynchronousTask`1.ExecuteSynchronously(CancellationToken executorCancellationToken) in C:\__w\1\s\src\PowerShellEditorServices\Services\PowerShell\Execution\SynchronousTask.cs:line 92
--- End of stack trace from previous location ---
   at Microsoft.PowerShell.EditorServices.Services.PowerShell.Execution.SynchronousTask`1.get_Result() in C:\__w\1\s\src\PowerShellEditorServices\Services\PowerShell\Execution\SynchronousTask.cs:line 58
   at Microsoft.PowerShell.EditorServices.Services.PowerShell.Execution.SynchronousTask`1.ExecuteAndGetResult(CancellationToken cancellationToken) in C:\__w\1\s\src\PowerShellEditorServices\Services\PowerShell\Execution\SynchronousTask.cs:line 108
   at Microsoft.PowerShell.EditorServices.Services.PowerShell.Host.PsesInternalHost.InvokeDelegate[TResult](String representation, ExecutionOptions executionOptions, Func`2 func, CancellationToken cancellationToken) in C:\__w\1\s\src\PowerShellEditorServices\Services\PowerShell\Host\PsesInternalHost.cs:line 526
   at Microsoft.PowerShell.EditorServices.Services.PowerShell.Console.PsrlReadLine.ReadLine(CancellationToken cancellationToken) in C:\__w\1\s\src\PowerShellEditorServices\Services\PowerShell\Console\PsrlReadLine.cs:line 35
   at Microsoft.PowerShell.EditorServices.Services.PowerShell.Host.PsesInternalHost.InvokeReadLine(CancellationToken cancellationToken) in C:\__w\1\s\src\PowerShellEditorServices\Services\PowerShell\Host\PsesInternalHost.cs:line 1064
   at Microsoft.PowerShell.EditorServices.Services.PowerShell.Host.PsesInternalHost.DoOneRepl(CancellationToken cancellationToken) in C:\__w\1\s\src\PowerShellEditorServices\Services\PowerShell\Host\PsesInternalHost.cs:line 963

推測爆炸點在 PowerShell 的指令自動完成功能，按 $ 帶出先前輸入過的 $t = .... 內容，上回用 $t 裝了超長文字(大約一萬個字元)，超出 REPL 某段程式長度上限，導致程式爆炸。

理論上將這筆超長指令從歷史清除就可了事，但 Clear-History 只會清除當前工作階段的歷史，爬文查到用 (Get-PSReadLineOption).HistorySavePath 可檢視指令歷史記錄檔路徑在 %APPDATA%\Microsoft\Windows\PowerShell\PSReadLine\Visual Studio Code Host_history.txt，果然在檔案找到該筆記錄。
註1：留意輸入指令時會覆寫檔案 註2：不同 PowerShell 執行環境有自己的存檔，VSCode 的 PowerShell Extension 在 Visual Studio Code Host_history.txt，一般指令視窗在 ConsoleHost_history.txt

刪掉過長文字指令再重啟 PowerShell Shell，總算排除一按 $ 就出錯的鬼問題。

In VSCode’s PowerShell terminal, encountering an error when using long input history can crash due to autocompletion. Deleting the problematic entry from the history file located in %APPDATA%\Microsoft\Windows\PowerShell\PSReadLine\Visual Studio Code Host_history.txt resolves the issue.