export function queryParamsFor(current, qp, defaults = {}) {
  const query = Object.assign({}, current || {});

  for ( const key of Object.keys(qp) ) {
    const val = qp[key];

    if ( typeof defaults[key] === 'undefined' ) {
      // There is no default
      query[key] = qp[key];
    } else if ( defaults[key] === false ) {
      // Value-less boolean flags
      if ( val ) {
        query[key] = null;
      } else {
        delete query[key];
      }
    } else if ( val === defaults[key] ) {
      // The value is the default
      delete query[key];
    } else {
      // The value is not the default
      query[key] = val;
    }
  }

  return query;
}