How can I tell which when clause contexts theia supports?

From: https://code.visualstudio.com/docs/getstarted/keybindings#_when-clause-contexts

[original thread by amiramw]

All of them should be supported: https://github.com/eclipse-theia/theia/issues/3986

You can double check in code, just search whether Theia registers them. They should be registered except for editors, them are coming from Monaco.

[amiramw]

where specifically in the code can I find those?

It probably would be worth to be able to generate all registered context keys, commands, keybinidngs and so on per an extension to generate README files for example and also get an overview. Instead of searching the code base each time.