ConEmu build: 170807 x64 (previous versions have this bug too)
OS version: Windows 7 x64
Used shell version: any GUI child window
If in Appearance settings the option to always show scrollbar is set, the following bug appears: when opening new tab with GUI window inside, there is a gap on the right. The width of the gap seems equal to the width of the scrollbar. After resizing ConEmu window or switching tabs, the gap disappears.
This problem doesn't exist if scrollbar is always hidden or set to auto show on mouse over (like it is set in default ConEmu configuration).
The bug can be reproduced with multiple different programs (tested: putty.exe, notepad.exe, speedcrunch.exe) so it is not a bug of child GUI window.
Steps to reproduce
Create task for a GUI window (e.g. putty.exe, notepad.exe, etc).
Change settings in Main >Appearance > Scrollbar to "Show".
Open the task with a GUI window.
The child window don't fill ConEmu window completely. There is the gap on the right side. Please see attached screenshots.
There should be no gap. The child window should populate all available space.
Upd: I decided to test if Notepad++ could be opened in ConEmu and found that described bug still appears if the child window is notepad++.exe . It may be that Notepad++ shows it's window in some different way than other applications. I can be wrong, but I think Notepad++ opens some hidden splashscreen-like window before opening main window.
Putty, Windows Notepad and SpeedCrunch open correctly now.
The line break is defined by the width of the ConEmu window and rendered also by ConEmu.
Definitely not. ConEmu is terminal, it shows what your node.js prints, and it's node.js choice when to do line break.
That is NOT a gap defined by scrollbar
The reported bug (this issue) for ChildGui was fixed year ago.
You problem is related to node.js (configuration or anything) and is offtopic here.