JSFiddle - React, Tailwind, and code Playground

JavaScript

(function() {

    var obj = {
        fn: function(a) {
            var f = v=> { 
            	debugger; 
            	console.log("Arguments length " + arguments.length);
            };
            return f(a, 6, 7, 8);
        }
    };
    obj.fn(1);
}
)();