Unexpected characters in VSCode PS Integrated shell commands

[ZZStoner]

Issue Description

After upgrading the PS Extension in VS Code to 2020.4.0, I noticed the PS Integrated Shell showing garbage characters when trying to type any commands.

Example showing strange extra characters after only typing dir:

Attached Logs

Note to Team: The README link to the Reporting Problems below returns a 404 Not Found.

Follow the instructions in the README about
capturing and sending logs.

Environment Information

Visual Studio Code

Name	Version
Operating System	Windows_NT x64 6.3.9600
VSCode	1.44.1
PowerShell Extension Version	2020.4.0

PowerShell Information

Name	Value
PSVersion	5.1.14409.1018
PSEdition	Desktop
PSCompatibleVersions	1.0 2.0 3.0 4.0 5.0 5.1.14409.1018
BuildVersion	10.0.14409.1018
CLRVersion	4.0.30319.42000
WSManStackVersion	3.0
PSRemotingProtocolVersion	2.3
SerializationVersion	1.1.0.1

Visual Studio Code Extensions

Visual Studio Code Extensions(Click to Expand)

Extension	Author	Version
csharp	ms-dotnettools	1.21.17
gc-excelviewer	GrapeCity	2.1.34
kuskus-extensions-pack	rosshamish	1.0.1
kuskus-kusto-color-themes	rosshamish	0.1.0
kuskus-kusto-language-server	rosshamish	1.0.1
kuskus-kusto-syntax-highlighting	rosshamish	1.1.8
material-icon-theme	PKief	4.0.1
mssql	ms-mssql	1.9.0
powershell	ms-vscode	2020.4.0
rainbow-csv	mechatroner	1.6.0
team	ms-vsts	1.161.0

[TylerLeonhardt]

Hi @ZZStoner I'm having trouble repro'ing this. Can you comment out everything in your $PROFILE and see if this still repros?

[ZZStoner]

Currently with v2020.4.0:

I cleared out my Microsoft.VSCode_profile.ps1 (well, it only has a single line which is a comment)
Then reloaded VS Code. It still reproed.
I then chose to downgrade to v2020.3.0

Downgraded to v2020.3.0:

The PS Profile is empty.
Typing the first command worked as expected with no artifacts...

I closed and reopened VS Code to make sure things worked consistently.
I then chose to upgrade back to v2020.4.0

Upgraded back to v2020.4.0 again:

The PS Profile is empty.
Still have crazy artifacts while typing.

Potentially related:

I noticed the garbage text seems to have the same format as the properties from Get-PSReadLineOption.

Sample from Get-PSReadLineOption:

ParameterColor                         : [90m"$([char]0x1b)[90m"[0m
PredictionColor                        : [38;5;238m"$([char]0x1b)[38;5;238m"[0m
SelectionColor                         : [30;47m"$([char]0x1b)[30;47m"[0m

The value of PredictionColor is interesting because the "238m" is also seen in my snips.

[TylerLeonhardt]

Ah this is the new prediction feature in PSReadLine.

@daxian-dbw can you take a look at this?

[daxian-dbw]

Sample from Get-PSReadLineOption:

ParameterColor                         : [90m"$([char]0x1b)[90m"[0m
PredictionColor                        : [38;5;238m"$([char]0x1b)[38;5;238m"[0m
SelectionColor                         : [30;47m"$([char]0x1b)[30;47m"[0m

This indicates that the VT100 escape sequences are not correctly handled by the VS Code terminal.
@TylerLeonhardt are you aware of any issues of the VS Code terminal related to VT100 support?

[TylerLeonhardt]

Hmm they should be handled correctly... @Tyriar do you have any thoughts?

@ZZStoner what version of Windows are you on?

[dnelson6]

I am also experiencing this same garbage text. Downgraded to v2020.3.0 and all is well.

Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion' | select EditionID, ProductName, CurrentBuildNumber

EditionID      ProductName                     CurrentBuildNumber
---------      -----------                     ------------------
ServerStandard Windows Server 2012 R2 Standard 9600 

[Tyriar]

If the terminal is printing then the terminal is likely not getting the escape character. You can check exactly when the terminal gets by following this https://github.com/microsoft/vscode/wiki/Terminal-Issues#enabling-escape-sequence-logging

[ZZStoner]

To follow up, I am also using Windows 2012 R2.

[TylerLeonhardt]

Just to get you unblocked... you can remove this folder:

C:\Users\[YOUR USER]\.vscode\extensions\ms-vscode.powershell-2020.4.0\modules\PSReadLine\

NOTE: If you're on insiders it's \.vscode-insiders\

If your console doesn't give you syntax highlighting, simply reinstall PSReadLine the normal way:

Install-Module PSReadLine -Force -AllowClobber