JSFiddle - React, Tailwind, and code Playground

HTML

<head> 
  <script src="https://cdn.jsdelivr.net/lodash/4.13.1/lodash.min.js"></script>
  
  
</head>
<body>
</body>

JavaScript

function customizer(objValue, srcValue) {
  return !objValue ? srcValue : objValue;
}
 
var defaults = _.partialRight(_.assignWith, customizer);
 
console.log(defaults({}, { 'a': 3, 'b': 0 }, { 'a': 1, 'b': 3 }));