Jupyter: make leaving edit mode better behaved

[slel]

Three examples to illustrate the problem. In all cases, start in edit mode in a code cell, say cell N.

A.

In edit mode in cell N, do the following steps at a high pace without waiting between each step for things to complete:

• type or paste some code
• hit Shift-Enter to run it
• hit Enter to enter edit mode in the next cell

Expected: things happen in order, regardless of lag:

• the typed or pasted code appears in cell N
• cell N gets run and focus moves to cell N+1
• we enter edit mode in cell N+1

Observed:

• the typed or pasted code appears in cell N (good)
• cell N+1 becomes blue, indicating it has focus and we are in command mode (good)
• cell N starts to run (good)
• somehow the cursor is still in cell N (strange)
• a newline appears at the end of cell N (bad)
• we do not enter edit mode in cell N+1 (bad)
• we end up in command mode at cell N+1 (bad)

User's next step: up-arrow to go back to cell N, hit Enter to enter edit mode, delete unwanted newline, hit Esc to enter command mode, wait, down-arrow to go to cell N+1, hit Enter to enter edit mode.

B.

Similarly, if after Shift-Enter, instead of hitting Enter, one hits M to make cell N+1 a markdown cell, or A to add a new cell between cells N and N+1, instead of the expected command-mode action happening (make cell markdown, resp. new cell above), these often result in the character "m", resp. "a", being appended to cell N.

User's next step: go back to cell N to remove extra M or A, then back to cell N+1.

C.

Similarly, starting in edit mode in a code cell, type (without waiting a lot between each keystroke) the sequence of keys Esc, m, Enter.

Expected:

• enter command mode
• cell becomes markdown
• enter edit mode again in the markdown cell

Observed:

• partly enter command mode, but with cursor still in cell N somehow
• character "m" and a newline appear in code cell
• end up in command mode, with cell still a code cell

User's next step: wait for CoCalc to be ready, hit Enter again to enter edit mode, remove unwanted newline and character "m", hit Esc, wait, hit M, wait, hit Enter. Get to desired state.

[williamstein]

I've never seen problems like this. Maybe you have a browser extension or something causing trouble, or maybe it was an old bug. Closing.