earnest-blog-2-example-6.js

const options = Object.freeze({
  async: true,
  page: 4
});

const awesomeFunction = options => {
  const updatedOptions = Object.assign({}, options, {
    offset: options.offset || 10
  });
  
  // do stuff with updatedOptions
};

awesomeFunction(options);
someOtherFunction(options);
yetAnotherFunction(options);