ANSI codes appearing as autocomplete visual artifacting

[mnooseman]

Environment

PS version: 5.1.14409.1018
PSReadline version: 2.1.0-beta1
os: 6.3.9600.16384 (winblue_rtm.130821-1623)
PS file version: 10.0.14409.1005 (rs1_srvoob.161208-1155)
HostName: Visual Studio Code Host
BufferWidth: 218
BufferHeight: 3000

Exception report

Steps to reproduce

Open Latest VSCode + Powershell-Preview extension in RDP session. Attempt to type any cmdlet in the Integrated Shell.

Expected behavior

Autocomplete working properly, showing potential commands.

Actual behavior

Observe that weird auto-completed artifacting appears, which seems to include ANSI codes. In the below image I had Typed "Get-"

[gilescope]

I wonder if you can integrate windows terminal into vscode because that’s the true fix for ansi codes appearing.

_{Sent with GitHawk}

[vexx32]

Visual Studio Code implements its own terminal for everything using xterm.js. It's also cross-platform so I don't think they can integrate a Windows-only component.

[SeeminglyScience]

If they were running a build of Windows that could install terminal (they appear to be running server 2k12), the escape codes would work fine anyway.

iirc PSReadLine has a check for when the OS doesn't support ANSI escapes and should revert to a simplier renderer.

Some possibilities:

1. bug in the check
2. bug in the simple terminal interface
3. maybe some escape sequences were added directly in the renderer bypassing the check

I never really looked at the code for the simple interface so some of the above might be nonsensical.

[daxian-dbw]

Thanks for reporting the issue. The issue has been fixed in the master branch (#1496), by making the predictive suggestion feature off by default. The predictive suggestion feature can be turned on by Set-PSReadLineOption -PredictionSource History (by default the PredictionSource is None). But if PSReadLine is used in a host that doesn't support VT100, that feature cannot be enabled -- Set-PSReadLineOption -PredictionSource History will throw error accordingly.