JSON.stringify with optional function-style replacer

[danielrentz]

In our project, we have a code place that wants to call JSON.stringify with an optional replacer function contained in a variable. This causes a type error now. Optional replacer still works with array type though.

const rnd = Math.random() > 0.5;
const replacer1 = rnd ? [""] : undefined;
const replacer2 = rnd ? (() => "") : undefined;

JSON.stringify({}, replacer1, 2);    // still works
JSON.stringify({}, replacer2, 2);    // used to work, now a type error

I think the "replacer" arg should be made optional in all three signatures. Calling the function explicitly with undefined (as in JSON.stringify({}, undefined, 2)) will still pick the first match.