Console not working with Interaction mode set to Terminal

[Jan Arman Parpin]

Description

I cannot use any Code Console when I've set the Interaction Mode to Terminal in the Code Console Settings tab.
Problems:

1. I cannot send any command.
2. Code completer does not work properly, does not accept Enter.

Reproduce

1. Go to 'Settings'
2. Click on 'Code Console' on the left
3. Change Interaction Mode to 'Terminal'
4. Start a any Console i.e. 'Python 3 (ipykernel)'
5. Try to send anything i.e. '1+1'

Expected behavior

A working Code Console.

Context

• Operating System and version: Archlinux
• Browser and version: Chrome
• JupyterLab version: 4.2.0

[Michał Krassowski]

Reproduced, looks like another bug introduced by jupyterlab/lumino#662. Working on adding a test and a fix right now.