PowerShell argument `WindowStyle -Hidden` is not respected when the default terminal application is Windows Terminal

[sachinjoseph]

Windows Terminal version

1.12.10393.0

Windows build number

Microsoft Windows NT 10.0.22549.0

Other Software

Software	Version
PowerShell.exe	Multiple Versions
pwsh.exe	Multiple Versions

Steps to reproduce

1. Set Windows Terminal as the default terminal application:
   .
   

2. Make sure to save changes to Windows Terminal Settings, and then using Windows Run, run pwsh -WindowStyle Hidden -Command Sleep 10:
   

Expected Behavior

A new PowerShell process launches (Windows Terminal), and it isn't visible. The window may flash for a second. PowerShell window shouldn't be displayed when it's launched with WindowStyle -Hidden.

Actual Behavior

A new PowerShell process launches (on Windows Terminal), and it is visible and remains visible (and waits) for 10 seconds.

Note: There is no repro for this issue with Windows Console Host as the default terminal application.

[zadjii-msft]

PowerShell/PowerShell#3028 looks like it's related. This probably requires quite a bit of thinking...

[malxau]

Dustin wrote a spec for this a while back that doesn't seem to have ever been merged:

#7337
https://github.com/microsoft/terminal/blob/ec27049553e9ca2135068edf8a9946a9d94ae2c4/doc/specs/%237335%20-%20Console%20Allocation%20Policy.md

Looking at it now the odd part is asking console processes to call ShowWindow. That doesn't seem to fit well with what Terminal is trying to do w.r.t. multi-tab, multi-pane, etc.

[sachinjoseph]

PowerShell/PowerShell#3028 looks like it's related. This probably requires quite a bit of thinking...

The console window being shown for a second may still be tolerable but with WT the window isn't hidden at all - there's no difference between using the PowerShell argument -WindowStyle Hidden and not using this argument when WT is the default terminal application.

[sachinjoseph]

This is a blocker for many applications such as rush that use PowerShell to run background tasks. Rush issue tracked here.