Nested functions do not evaluate arguments

[Jaspooky]

When functions are not defined at the top level but instead attached as part of an object, their arguments don't appear to actually be evaluated. For example below, reverseString works fine when declared as a top level function, but not when referenced as a property of a wrapping object.

MRE

const jsonata = require('jsonata');
 
 const lib = () => ({
   reverseString: (str) => str.split('').reverse().join(''),
 });
 
 const createJsonata = (expression) => {
   const instance = jsonata(expression);

   instance.registerFunction('lib', lib);
   instance.registerFunction('reverseString', lib().reverseString);
 
   return instance;
 };
 
 const data = { name: 'Jasper' };
 
 const works = createJsonata("( $str := $.name; $lib().reverseString($str) )")
   .evaluate(data); //?
   // 'repsaJ'
 
 const alsoWorks = createJsonata("$reverseString($.name)")
   .evaluate(data); //?
   // 'repsaJ'
 
 const fails = createJsonata("$lib().reverseString($.name)")
   .evaluate(data); //?
   // TypeError: Cannot read properties of undefined (reading 'split')