@automattic/calypso-products/src/is-titan-mail.ts

This module contains information about the various products sold within calypso, such as product slugs, plan intervals, etc.

import { camelOrSnakeSlug } from './camel-or-snake-slug';
import { TITAN_MAIL_SLUGS } from './constants';
import type { WithCamelCaseSlug, WithSnakeCaseSlug } from './types';

export function isTitanMail( product: WithCamelCaseSlug | WithSnakeCaseSlug ): boolean {
	return ( TITAN_MAIL_SLUGS as ReadonlyArray< string > ).includes( camelOrSnakeSlug( product ) );
}