When invoking `prog-fill-reindent-defun' from inside a bash-ts-mode buffer, an exception (regardless of where point is), an error is raised that reads
Invalid predicate, see ‘treesit-thing-settings’ for valid forms for a predicate: nil
Investigation reveals that `prog-fill-reindent-defun' calls `treesit-node-match-p' with 'text as the second argument, which can only succeed if `(assq 'text (assq 'bash treesit-thing-settings))' is non-nil; whereas the corresponding setting for `treesit-thing-settings' prepared by `bash-ts-mode', doesn't provide a value for 'text (only for 'sentence).