I would propose to introduce a new keyword paths for rebuild and restart actions, since the path has a 1 to 1 relation to target for sync++ actions.
Under this assumption, the new keyword paths you could also have the pattern matching safely as it would support multiple files (as the pattern matching might resolve to more than one file). As for path, we should be careful for the pattern matching; perhaps returning an error explaining the matched files if it resolves to multiple files.

Or we can change path to be either a string or a list in the json schema and during validation make sure the above assumptions. However, I think usability becomes more complicated as there are different conditions for different actions

@jhrotko paths sounds reasonable, at the slight expense of the user having to understand that both path and paths exist. Which is not obscene by any stretch of the imagination, just slightly more mental overhead for the user.

I guess it's a tradeoff between making the API as smooth as possible for the user and an implementation that actually achieves the desired behaviour. I am guess that extending the behaviour of path has complications on the implementation I am unaware of.

I created a POC in these branches (feature-wild-star-watch-path):

• compose
• compose-go

in these branches the implementation is under the path which can now receive a string or a list of strings and also validates the * pattern matching.

If you want to try, clone my fork/branch and run make build.

in your compose.yml you can write something along the lines

...
develop:
  watch:
    - path: SOME/PATH/*.txt
      action: rebuild
    - path: 
        - FILE1
        - FILE2
      action: restart

you can run with the specific compose build (from the make build) by running

PATH/TO/JHROTKO/FORK/compose/bin/build/docker-compose up --watch

On #12584 I proposed to keep using a single path as base to monitor filesystem for changes, and introduce a dedicated include attribute so one can declare patterns to restrict which actual file changes should be considered by action:

    develop:
        watch:
        - action: rebuild
          path: frontend
          include:
            - *.json
            - *.js