How to trick Powershell into thinking it's not redirected

[HerrNamenlos123]

Hi!

Sorry if this is the wrong place to ask, but it's at least a starting point for me.

I want to create my own Terminal emulator, and a few tests showed that it is relatively simple to just call cmd or powershell in a subprocess, and redirect stdout and stdin. Then I can simply render stdout in a text buffer.

I am using reproc/reproc++ to call powershell in a subprocess and redirect the pipes. I would build the emulator in Windows-subsystem and a rendering canvas that renders the content of stdout. I will implement VT parsing using a third party library I have not chosen yet.

Now, the issue is that when I call powershell (and I have Set-PSReadLineOption -PredictionSource History enabled), then I get a huge warning:

Set-PSReadLineOption : The predictive suggestion feature cannot be enabled because the console output doesn't support 
virtual terminal processing or it's redirected.

So now my question is what do I have to do so that powershell operates normally and does not care it's redirected? I am afraid that even if I find a workaround for powershell, other programs might also break down the road, so how can I fix the root cause?

If there is a better way to emulate a terminal and my entire approach is flawed, I am also open for suggestions... Thanks!