apps-script-utils 2.1.1 Help

nonValidEmail

function nonValidEmail<T>(value: T | string): value is T;

nonValidEmail(value) is the same test as !isValidEmail(value), written so that a guard clause reads as a sentence rather than as a negation.

The address is split at a single @: the domain is checked the way isValidDomain checks one, and the local part must be non-empty and free of spaces. It is a format check, not proof that the mailbox exists.

isX and nonX answer a question and never interrupt control flow; requireX and requireNonX hand the value back or throw. The scheme is explained in Validation conventions.

Parameters

Parameter

Type

Description

value

T \| string

The value to check.

Returns

boolean — true when the value is not an email address; otherwise false.

In TypeScript the guard narrows value to T inside the branch.

Examples

What passes and what does not

nonValidEmail("user@@example.com"); // => true nonValidEmail("user@"); // => true nonValidEmail("example.com"); // => true nonValidEmail(""); // => true nonValidEmail("user@example.com"); // => false nonValidEmail("first.last@sub.example.co.uk"); // => false

See also

Source

src/lang/string/nonValidEmail.ts

23 September 2026
nonUrlnonValidLocale

This documentation was generated with AI (Claude) from the library's source code.