Validating an email address using different methods

Cognito.ts

// Using AWS Cognito via TypeScript

import { AdminCreateUserCommand, AdminDeleteUserCommand, CognitoIdentityProviderClient } from '@aws-sdk/client-cognito-identity-provider';

const addresses = [
    // valid
    'name@example.com',
    'name.name@example.com',
    '"name..name"@example.com',
    'name@localhost',
    'nåme@example.com',
    'aA0!#$%&\'*+-/=?^_`{|}~@example.com',

    // invalid
    'name.example.com',
    '.name@example.com',
    'name.@example.com',
    'name..name@example.com',
    '<name>@example.com',

    // invalid host names
    'name@-example.com',
    'name@example-.com',
    'name@example.com-',
];

const cognito = new CognitoIdentityProviderClient({
    region: 'eu-west-1'
});
const userPoolId = process.env.USER_POOL_ID;

addresses.forEach(async (address) => {
    await cognito.send(new AdminCreateUserCommand({
        UserPoolId: userPoolId,
        Username: address,
        MessageAction: 'SUPPRESS',
    })).then(async () => {
        console.log(`${address} is valid`);

        // clean up
        await cognito.send(new AdminDeleteUserCommand({
            UserPoolId: userPoolId,
            Username: address
        })).catch((error) => {
            console.log(`Unable to clean up ${address} - ${error}`);
        });
    }).catch((error) => {
        console.log(`${address} is NOT valid - ${error}`);
    });
});

Program.cs

// Using Model Annotations in .NET 6

using System.ComponentModel.DataAnnotations;
using System;

var addresses = new string[] {
    // valid
    "name@example.com",
    "name.name@example.com",
    "\"name..name\"@example.com",
    "name@localhost",
    "nåme@example.com",
    "aA0!#$%&'*+-/=?^_`{|}~@example.com",
			
    // invalid
    "name.example.com",
    ".name@example.com",
    "name.@example.com",
    "name..name@example.com",
    "<name>@example.com",
	
    // invalid host names
    "name@-example.com",
    "name@example-.com",
    "name@example.com-",
};

foreach (var address in addresses)
{
    var obj = new DomainObject { EmailAddress = address };

    try
    {
        Validator.ValidateObject(obj, new ValidationContext(obj, null, null), true);
        Console.WriteLine($"{address} is valid");
        
    }
    catch (ValidationException exception)
    {
        Console.WriteLine($"{address} is NOT valid - {exception.Message}");
    }
}

class DomainObject
    {
        [EmailAddress]
        public string? EmailAddress { get; set; }
}