Circular reference

circular_test.js

//File a.js:
var b = require('./b');

exports.A = function () {
  console.log('A');
  b.B();
};


//File b.js:
var a = require('./a');
var A;
//A = a.A; <--- can't do this

exports.B = function () {
  console.log('B');
  A = a.A; // <-- can do this
  console.log('A ->', A);
};