JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/sinon.js/1.7.3/sinon-min.js"></script>

JavaScript

var obj = {
    foo: function () {
        console.log('foo');
    }
};

var stub = (function () {
    var originalFoo = obj.foo;
    return sinon.stub(obj, 'foo', function () {
        console.log('stub');
        originalFoo();
    });
}());

obj.foo();