How to convert return values from JSON Path functions to text

[Thomas Kellerer]

The new JSON path functions in Postgres 12 are really convenient, however I 
cannot figure out how to properly convert their return values to a text value.

E.g. select jsonb_path_query_first('{"a": "foo"}', '$.a') returns a JSONB value.
Casting it to text, still yields "foo" (with quotes), rather than foo (without 
quotes)

For the time being I am using something like this:

    create function jsonb_to_text(p_value jsonb)
      returns text
    as
    $$
      select case jsonb_typeof(p_value)
               when 'string' then trim('"' from p_value::text)
               else p_value::text
             end;
    $$
    language sql
    immutable
    strict;

But that feels a bit "heavyweight" - I was hoping for an easier (and more 
efficient) way to do that.

Thomas