Corrupted text added during save, not during save without formatting

System Details

System Details Output

### VSCode version: 1.43.0 78a4c91400152c0f27ba4d363eb56d2835f9903a x64

### VSCode extensions:
ms-mssql.mssql@1.9.0
ms-vscode.csharp@1.21.3
ms-vscode.powershell@2020.3.0
ms-vscode.powershell-preview@2020.2.0 <-- Disabled

### PSES version:

### PowerShell version:

Name                           Value
----                           -----
PSVersion                      5.1.14393.2879
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0, 5.0, 5.1.14393.2879}
BuildVersion                   10.0.14393.2879
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

Issue Description

When I'm making edits to PowerShell scripts in VS Code (after a long day) sometimes Ctrl-S (Save) is adding corrupted text to the file. You can see it appear in the editor window and then get saved.

• If you hit save repeatedly, more and more corruption occurs.
• If you use 'File: Save Without Formatting' then the corrupted text doesn't get added.
• I have 'Editor: Format On Save' disabled. I checked User/Workspace/Folder settings.
• My workspace has 'Editor: Trim Auto Whitespace', 'Editor: Trim Final Newlines', 'Editor: Trim Trailing Whitespace' enabled, but when I disabled these, and hit Ctrl-S, the corruption was still added.

When the problem occurs, it's only in a single window/file. Reloading VS Code makes the problem go away. I didn't try closing just that code window.

Attached Logs

Unfortunately I got to this bit before I reloaded my session (though this happens every few days so I thought I'd open the issue now). The only thing of note in EditorServices.log is below but I'm not sure if it was related, because I think it was about 10 minutes before this happened, BUT I had the same problem on another file at around the same time:

2020-03-18 18:23:47.706 +08:00 [ERR] Execution of the following command(s) completed with errors:

    Microsoft.PowerShell.Core\Get-Command $true -ErrorAction Ignore


2020-03-18 18:30:16.037 +08:00 [ERR] Invalid Range (Parameter 'range')
2020-03-18 18:30:16.037 +08:00 [ERR] Formatter returned null result
2020-03-18 18:30:32.051 +08:00 [FTL] Failed to handle request textDocument/didChange
System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values. (Parameter 'Position 26:17 is outside of the column range of 1 to 14.')
   at Microsoft.PowerShell.EditorServices.Services.TextDocument.ScriptFile.ValidatePosition(Int32 line, Int32 column) in D:\a\1\s\src\PowerShellEditorServices\Services\TextDocument\ScriptFile.cs:line 308
   at Microsoft.PowerShell.EditorServices.Services.TextDocument.ScriptFile.ApplyChange(FileChange fileChange) in D:\a\1\s\src\PowerShellEditorServices\Services\TextDocument\ScriptFile.cs:line 332
   at Microsoft.PowerShell.EditorServices.Handlers.TextDocumentHandler.Handle(DidChangeTextDocumentParams notification, CancellationToken token) in D:\a\1\s\src\PowerShellEditorServices\Services\TextDocument\Handlers\TextDocumentHandler.cs:line 68
   at OmniSharp.Extensions.LanguageServer.Server.Pipelines.ResolveCommandPipeline`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
   at MediatR.Pipeline.RequestPostProcessorBehavior`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
   at MediatR.Pipeline.RequestPreProcessorBehavior`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
   at OmniSharp.Extensions.JsonRpc.RequestRouterBase`1.RouteNotification(TDescriptor descriptor, Notification notification, CancellationToken token)
2020-03-18 18:30:33.024 +08:00 [FTL] Failed to handle request textDocument/didChange
System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values. (Parameter 'Position 41:5 is outside of the column range of 1 to 2.')
   at Microsoft.PowerShell.EditorServices.Services.TextDocument.ScriptFile.ValidatePosition(Int32 line, Int32 column) in D:\a\1\s\src\PowerShellEditorServices\Services\TextDocument\ScriptFile.cs:line 308
   at Microsoft.PowerShell.EditorServices.Services.TextDocument.ScriptFile.ApplyChange(FileChange fileChange) in D:\a\1\s\src\PowerShellEditorServices\Services\TextDocument\ScriptFile.cs:line 332
   at Microsoft.PowerShell.EditorServices.Handlers.TextDocumentHandler.Handle(DidChangeTextDocumentParams notification, CancellationToken token) in D:\a\1\s\src\PowerShellEditorServices\Services\TextDocument\Handlers\TextDocumentHandler.cs:line 68
   at OmniSharp.Extensions.LanguageServer.Server.Pipelines.ResolveCommandPipeline`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
   at MediatR.Pipeline.RequestPostProcessorBehavior`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
   at MediatR.Pipeline.RequestPreProcessorBehavior`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
   at OmniSharp.Extensions.JsonRpc.RequestRouterBase`1.RouteNotification(TDescriptor descriptor, Notification notification, CancellationToken token)
2020-03-18 18:31:04.029 +08:00 [WRN] textDocument/codeAction skipping diagnostic with empty Code field: PowerShell Unexpected token '$ParameterValue' in expression or statement.
2020-03-18 18:31:13.261 +08:00 [WRN] textDocument/codeAction skipping diagnostic with empty Code field: PowerShell unexpected token '$ParameterValue', expected 'begin', 'process', 'end', or 'dynamicparam'.

What I did capture though were images of the corruption. I had just changed the type and property name, so, it seemed to be corrupting with part of what was previously removed.

Pre save

Save 1

Save 2

Save 3

Reproduce the issue in VS Code with the PowerShell extension by comparing repeated Save with Save Without Formatting, using the captured logs as the starting point. Read ScriptFile.ValidatePosition/ApplyChange and TextDocumentHandler.Handle at the stack-trace locations; done means repeated saves no longer insert corrupted text or produce the reported range errors.