javascript get function body

Question

I have a function e.g.

var test = function () {alert(1);}

How can I get the body of this function?

I assume that the only way is to

Answer 1

This code provides the body when using ES6 arrow functions like var testFn=(q)=>q+1;

function getFunctionBody(test){  
    var entire = test.toString(); // note: not safe-guarded; this part may fail like this!
    return entire.substring((entire.indexOf("{")+1)||(entire.indexOf("=>")+2),  entire.lastIndexOf("}")!==-1?entire.lastIndexOf("}"):entire.length);
}

//testing/showcase code
var tests = [
    function () {alert(1);},
    ()=>{return 1;},
    q=>q+1
];

for (var i=0;i

I originally submitted this code as an edit to polygenelubricants accepted answer, but it was rejected as the changes were considered to be too drastic.