wp_mail(): Full Test

• Tell the test suite to expect mail from this method
• Call the plugin's method
• Verify the mail

class LoginTest extends TestCase {

    public function test_notify_login() {
        self::$mail_file_basename = __METHOD__;

        $actual = self::$o->notify_login($this->user_name);
        $this->assertTrue($actual, 'Bad return value.');

        $this->check_mail_file();
    }
}