wordpress-develop/tests/phpunit/tests/formatting/isEmail.php

<?php

/**
 * @group formatting
 */
class Tests_Formatting_IsEmail extends WP_UnitTestCase {
	function test_returns_the_email_address_if_it_is_valid() {
		$data = array(
			'bob@example.com',
			'phil@example.info',
			'ace@204.32.222.14',
			'kevin@many.subdomains.make.a.happy.man.edu',
			'a@b.co',
			'bill+ted@example.com',
		);
		foreach ( $data as $datum ) {
			$this->assertSame( $datum, is_email( $datum ), $datum );
		}
	}

	function test_returns_false_if_given_an_invalid_email_address() {
		$data = array(
			'khaaaaaaaaaaaaaaan!',
			'http://bob.example.com/',
			"sif i'd give u it, spamer!1",
			'com.exampleNOSPAMbob',
			'bob@your mom',
			'a@b.c',
		);
		foreach ( $data as $datum ) {
			$this->assertFalse( is_email( $datum ), $datum );
		}
	}
}