JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://rawgit.com/dharmafly/jsonpatch.js/master/lib/jsonpatch.js"></script>
<body>
    <blockquote> <pre id="item">foo</pre>

    </blockquote>
</body>

JavaScript

mydoc = {
    "baz": "qux",
        "foo": "bar",
        "list": [1, 2, 3]
};
thepatch = [{
    "op": "replace",
        "path": "/baz",
        "value": "boo"
}, {
    "op": "add",
        "path": "/list/0",
        "value": "hi"
}];


patcheddoc = jsonpatch.apply_patch(mydoc, thepatch);
document.getElementsByTagName("pre")[0].innerHTML = JSON.stringify(patcheddoc, undefined, 2);