JSONMatch array patch invalid tokens in Studio, sparse documentation

[fabien]

Describe the bug

Some tokens seem to be not implemented in Studio, while the backend actually handles them (eg. the update is performed, which is apparent after full browser reload of the document).

Also, the documentation is too sparse on what JSONMatch actually does, when to use it, how it compares to GROQ, and how to use it properly using the JS client to perform mutations. In particular, any examples of patch updates (set, inc, dec, ...) on array items are missing entirely.

The constraints mentioned here https://www.sanity.io/docs/json-match#9wMQqAol are also quite limiting, because most often you require intersection instead of union.

Steps to reproduce the behavior

I'm running this script using sanity exec:

client.patch('c3f54014-12cb-49f3-ba4c-734d3586382f', (p) =>
  p.set({
    [`variants[stock >= 20].stock`]: 20,
  })
);

Expected behavior

Studio should handle the update correctly.

Screenshots

Which versions of Sanity are you using?

@sanity/cli 2.10.0 (up to date)
@sanity/base 2.10.0 (up to date)
@sanity/components 2.2.6 (up to date)
@sanity/core 2.10.0 (up to date)
@sanity/default-layout 2.10.0 (up to date)
@sanity/default-login 2.8.0 (up to date)
@sanity/desk-tool 2.10.1 (up to date)
@sanity/vision 2.10.0 (up to date)

[fabien]

Related: #2421