Validate field matches another?

[viveleroi]

What's the best way to ensure a field's value matches the value of another? For example, two password fields matching?

I don't see any way to do this via validationSchema so I assume I need a per-field validation object that reads the value of another field? I'm just not sure on how to get the value of the other field in this context.

 function validateUsername(value) {
   let error;
   if (value === otherPasswordField.value) { // ? how do I get the other field
     error = 'Passwords must match';
   }
   return error;
 }```