JSFiddle - React, Tailwind, and code Playground

JavaScript

var ModuleA = function() {}

ModuleA.prototype = (function () {
    return {
        someMethod: function () {
            return 'foo';
        }
    };
}());

var ModuleB = function(moduleA) {
    this.innerModule = moduleA;
}

ModuleB.prototype = (function () {
    return {
        doStuff: function () {
            return this.innerModule.someMethod();
        }
    };
}());

var moduleA = new ModuleA();

var moduleB = new ModuleB(moduleA);
console.log(moduleB.doStuff());