// https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#validitystate
[Exposed=Window]
interface ValidityState {
    readonly attribute boolean valueMissing;
    readonly attribute boolean typeMismatch;
    readonly attribute boolean patternMismatch;
    readonly attribute boolean tooLong;
    readonly attribute boolean tooShort;
    readonly attribute boolean rangeUnderflow;
    readonly attribute boolean rangeOverflow;
    readonly attribute boolean stepMismatch;
    readonly attribute boolean badInput;
    readonly attribute boolean customError;
    readonly attribute boolean valid;
};