react-bootstrap-typeahead/es/utils/validateSelectedPropChange.js

React typeahead with Bootstrap styling

import warn from './warn';
export default function validateSelectedPropChange(prevSelected, selected) {
  var uncontrolledToControlled = !prevSelected && selected;
  var controlledToUncontrolled = prevSelected && !selected;
  var from, to, precedent;

  if (uncontrolledToControlled) {
    from = 'uncontrolled';
    to = 'controlled';
    precedent = 'an';
  } else {
    from = 'controlled';
    to = 'uncontrolled';
    precedent = 'a';
  }

  var message = "You are changing " + precedent + " " + from + " typeahead to be " + to + ". " + ("Input elements should not switch from " + from + " to " + to + " (or vice versa). ") + 'Decide between using a controlled or uncontrolled element for the ' + 'lifetime of the component.';
  warn(!(uncontrolledToControlled || controlledToUncontrolled), message);
}