How to run pre-push git hook only when files in a subfolder have changed since the last push?

I’m trying to run a git hook in a monorepo, where our React client is in a subfolder. I only want the hook to run when files in that subfolder have changed. This means that I need to somehow conditionally run only if the commits since I last pushed have had files change in that particular subfolder. e.g.

-- project
   -- files
   -- subfolder
      -- files I care about

and some git command like git show and outputs any files that have been changed in any commit since I last pushed. It also needs to not be branch specific, but know which branch I’m on and compare to unpushed commits on the same branch.

I’ve started out trying to do something like

if git show --name-only -r --stat --oneline HEAD^^..HEAD | grep -q 'ReactClient/'; then
  npm run verify
fi

but that only shows changed files from the last two commits