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

React typeahead with Bootstrap styling

import warn from './warn';
export default function validateSelectedPropChange(prevSelected, selected) {
    const uncontrolledToControlled = !prevSelected && selected;
    const controlledToUncontrolled = prevSelected && !selected;
    let from, to, precedent;
    if (uncontrolledToControlled) {
        from = 'uncontrolled';
        to = 'controlled';
        precedent = 'an';
    }
    else {
        from = 'controlled';
        to = 'uncontrolled';
        precedent = 'a';
    }
    const 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);
}