Here's some sample code you might want to test.
In src/Email.php:
<?php declare(strict_types=1);
namespace example;
final class Email
{
private function __construct(public readonly string $email)
{
}
static public function fromString(string $email): self
{
if (false === \filter_var($email, \FILTER_VALIDATE_EMAIL))
{
throw new \InvalidArgumentException(
\sprintf('"%s" is not a valid email address', $email)
);
}
return new self($email);
}
public function __toString(): string
{
return $this->email;
}
}
If using Composer, you can autoload the code by putting something like the following in composer.json:
{
"autoload": {
"classmap": ["src/"]
}
}
Then create the autoloader:
$ composer install
With this done, you can test the code.