Return true if given path would present a Formula file in this Tap.
Accepts both absolute path and relative path (relative to this Tap's path)
It offer an abstraction such that caller would not need to worry about
low level file system in the tap.
It will be used in `brew pull` and `brew update`.
ClosesHomebrew/homebrew#49191.
Signed-off-by: Xu Cheng <xucheng@me.com>
Tests shouldn't fail in case of an unavailable network or a deliberately
disabled access to the GitHub API.
ClosesHomebrew/homebrew#47670.
Signed-off-by: Martin Afanasjew <martin@afanasjew.de>
