Code editor settings can only be enabled, not disabled in Notebook

[krassowski]

Description

Checking a setting like Auto Closing Brackets, Highlight the active line, Highlight white spaces and others in notebook enables it but unchecking does not disable it afterwards.

Reproduce

1. Open a notebook and Settings → Notebook
2. Enable Highlight the active line
3. Click on the cell, see active line highlighted
4. Disable Highlight the active line
5. Click on the same cell, see active line remains hihglighted
6. Create a new cell, see that the settings are ok in newly created cells

Expected behavior

Settings get reflected in the existing cells

Context

• Browser and version: Chrome
• JupyterLab version: 4.0.6 and 4.1.0a1

[JasonWeill]

Does the "disabled" setting show up as enabled in the settings editor after you reload your JupyterLab session?

[krassowski]

Yes. The issue is that existing cells do not ever get extensions de-registered, not that the settings system is not saving. I had included step 6. Create a new cell, see that the settings are ok in newly created cells to hint at it.

[firai]

I'm not sure if it's the same issue, but I'm noticing that changes to CodeMirror settings only update CM instances when the new value is different from the default. When they are changed back to the default value, the behavior sticks to the previous value. You can see this by changing the cursor blinking rate in the notebook settings. I'm also experiencing this with settings for a new CM extension as well.