JSFiddle - React, Tailwind, and code Playground

HTML

<textarea id="myTextArea">array('a'=>'goat', 'b' => 'dog')</textarea>

JavaScript

var str = document.getElementById("myTextArea").value,
    json = "{" + str.slice(6, -1).replace(/=>/g,":").replace(/'/g,"\"") + "}";
    console.log(json);
    var obj = JSON.parse(json);
    console.log(obj);