ArgumentCountError trying to use validation

I'm getting an error (below) that doesn't quite make sense to me.
CI4.3.1
MariaDB 10.4.27
PHP7.4.33
Windows 11
XAMPP 3.3.0

Code:

ArgumentCountError

Too few arguments to function CodeIgniter\Validation\Validation::__construct(), 0 passed in C:\Users\objec\PhpstormProjects\opensourcepos\vendor\codeigniter4\framework\system\Validation\Validation.php on line 596 and exactly 2 expected

In my Controller (\app\Controllers\Login.php) I have:

PHP Code:

            if (strtolower($this->request->getMethod()) !== 'post')
            {
                return view('login', $data);
            }

            $rules = [
                'username' => 'required'
            ];

            if(!$this->validate($rules)
            {
                return view('login', $data);
            } 


On first load of the view, I have no issues because validate is not being called. When I click submit on the form it errors and the stack trace points to

PHP Code:

if(!$this->validate($rules) 


\CodeIgniter\Validation shows me the function

PHP Code:

$rules = [];

    protected function validate($rules, array $messages = []): bool
    {
        $this->setValidator($rules, $messages);

        return $this->validator->withRequest($this->request)->run();
    } 


and that does clearly show that it takes two arguments. At first I thought there was a problem with the documentation because the example, like my code calls validation with a single empty array for $rules, not two arguments, but I think this is shown this way in the example because the second parameter gets passed as null when no 2nd parameter is specified. Regardless, even when I pass a value in the array and pass a message array I still get this error.

What's puzzling to me is that it's saying that I've passed zero arguments.

---

I'm seeing now that it's complaining about the Validation constructor, not the validate() function. The thing is, that I don't think I'm doing anything different from the example code in the CI4 documentation, so I don't understand why it's not getting the expected $config and $view

PHP Code:

public function __construct($config, RendererInterface $view) 


Code:

Too few arguments to function CodeIgniter\Validation\Validation::__construct(), 0 passed in C:\Users\objec\PhpstormProjects\opensourcepos\vendor\codeigniter4\framework\system\Validation\Validation.php on line 596 and exactly 2 expected

The first thing you do is to see the source code.

ci-phpunit-test | CodeIgniter Testing Guide | CodeIgniter 3 to 4 Upgrade Helper

Turns out it was a custom ruleset from CI3 that was causing it to puke. Removing it as a Ruleset causes validation to work properly.