`onChange` signature doesn't look correct

[nifanic]

AFAIK onChange argument holds current value of string type.

If so, the signature should be—

(e: string) => void

… but the current onChange signature is—

(e: React.ChangeEvent<HTMLInputElement | HTMLTextAreaElement>) => void

… because MuiPhoneNumberProps type extends standard TextFieldProps—

// src/global.d.ts

export type MuiPhoneNumberProps = TextFieldProps & {
  autoFormat?: boolean;
  countryCodeEditable?: boolean;
  defaultCountry?: string;
  disableAreaCodes?: boolean;
  disableCountryCode?: boolean;
  disableDropdown?: boolean;
  dropdownClass?: string;
  enableLongNumbers?: boolean;
  excludeCountries?: string[];
  inputClass?: string;
  onlyCountries?: string[];
  preferredCountries?: string[];
};

[nifanic]

The original component is not offering type definitions. The above code snippets are from my codebase. Not an issue.