Getting names of function arguments

Question

We have a function:

function Foo (a,b,c) {
  return a + b + c;
}

Need to get names of Foo arguments outside from the function. The result should be:

Array['a', 'b', 'c']

Foo.arguments returns null.

The only way I see is calling Foo.toString() and then parsing the result.

Is there another more correct way to get the names?

Can you refactor the function to receive an object with structure `{ 'a': null, 'b': null, 'c': null }`? Code smell? — sudo, Mar 13 '19 at 07:56
No, it is a function from dependency and i cannot refact it. — Alexander Ladonin, May 22 '19 at 10:12

score 1 · Accepted Answer · answered Mar 13 '19 at 07:57

1

No, using Function#toString seems to be the way to go:

 const str = Foo.toString();
 const args = str.substr(str.indexOf("("), str.indexOf(")")).split(",").map(it => it.trim());

answered Mar 13 '19 at 07:57

Jonas Wilms

1 Answers1