JSFiddle - React, Tailwind, and code Playground

JavaScript

var withVariables = function(func, vars) {
   for (var v in vars){
       this[v] = vars[v];
   }
   func()
   for (var v in vars){
       delete this[v];
   }
};

// using an anonymous function
withVariables(
    function () {
        console.log('anonymous: ', foo);   
    },
    {
        'foo':'bar'   
    }
); // output: bar

// using a function reference
var myFunction =function () {
    console.log('myFunction: ', foo);   
};
withVariables(myFunction, {
    'foo':'bar'   
}); // output: bar

console.log(foo); // output: undefined