Theia: [preferences] bogus initial preference group

[vince-fugnitto]

Description

There is a bogus preference group node which does not contain any child preferences.

Steps to reproduce

1. Open the preferences widget (F1 and select Settings: Open Preferences).
2. Notice the bogus group node.

Theia as of c2e2308 (no plugins present).

[vince-fugnitto]

It has to do with the following preference:
https://github.com/theia-ide/theia/blob/c2e23083b905130276238477646b72d298d47d0d/packages/debug/src/browser/preferences/launch-preferences.ts#L28
And how we calculate the group name:
https://github.com/theia-ide/theia/blob/c2e23083b905130276238477646b72d298d47d0d/packages/preferences/src/browser/preferences-tree-widget.ts#L553-L555

---

Other preferences have the following format {group-name}.{preference-name}

[vince-fugnitto]

@akosyakov is this a preference that should not be displayed in the tree?
I see that VSCode has the same preference defined.

[akosyakov]

If it is defined in user, workspace or workspace folder settings.json files then yes, if it is coming from launch.json then probably not.

Generally splitting looks bogus, obviously there can be a preference name without ..

[vince-fugnitto]

Generally splitting looks bogus, obviously there can be a preference name without ..

If for whatever reason we can't calculate the group name, for example like in launch, I'll place these preferences under a common group called Other. Would that be acceptable?

[akosyakov]

Could be alright for now, alternatively for embeddable configurations use a section name as a group and it children as properties. One can check if with PreferenceConfigurations.isSectionName.