Function insert

packages/formik/src/FieldArray.tsx:89–97

(
  arrayLike: ArrayLike<T>,
  index: number,
  value: T
)

};

export const insert = <T,>(
  arrayLike: ArrayLike<T>,
  index: number,
  value: T
) => {
  const copy = copyArrayLike(arrayLike);
  copy.splice(index, 0, value);
  return copy;
};

export const replace = <T,>(
  arrayLike: ArrayLike<T>,