Improve your command lines skill. free and open source

This seems to be well implemented. It's actually running the commands and then checking for the necessary post conditions.

The command editor has serious problems. When you try to insert a character into the middle of a command line, everything to the right disappears. I'm referring here to a command line recalled with up arrow. I can't reproduce this on the current line because I can't use the left arrow key at all to move left. Left arrow is treated as submitting the command for testing.

This would be a good area to concentrate on.

I'm currently on mobile, Android phone with Chrome, using Hacker's Keyboard. Maybe on desktop things are different.