Definition
HTML Standard defines 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;
};