Bug: Validation passes if key does not exist when using asterisk

[puwnd]

PHP Version

8.1

CodeIgniter4 Version

4.4.1 OR 4.3.5

CodeIgniter4 Installation Method

Composer (using codeigniter4/appstarter)

Which operating systems have you tested for this bug?

Linux

Which server did you use?

apache

Database

No response

What happened?

If I use the asterisk in the validation rule, it does not check for non existing key.
There are two workarounds, but I guess they are not the best solutions.

1. Add a default value with the given key
2. Use with numbers instead of asterisk

Steps to Reproduce

In any controller I use the following snippet in the initController method.

        <?php
        $requestData = [
            'contacts' => [
                'friends' => [
                    ['name' => 'Fred Flinstone', 'age' => 20],
                    ['age' => 21], // 'name' key does not exist
                ]
            ]
        ];

        // $requestData['contacts']['friends'][1]['name'] ??= null; // Workaround for non existing keys

        $this->validator = Services::validation();
        $this->validator->setRules(
            [
                'contacts.friends.*.name' => 'required', // The "*" does not check for non existing keys and pass validation
                // 'contacts.friends.0.name' => 'required', // With this solution works fine even if the key does not exist
                // 'contacts.friends.1.name' => 'required', // With this solution works fine even if the key does not exist
            ]
        );

        dd($this->validator->run($requestData), $this->validator->getErrors());

Expected Output

I think the validation should check for it and fail if key does not exist (if there is a rule for it). So in my case the output should be:

$this->validator->run(...) boolean false
$this->validator->getErrors() array (1)
contacts.friends.1.name => string (46) "The contacts.friends.*.name field is required."

Now I get this:
$this->validator->run(...) boolean true
$this->validator->getErrors() array (0)

Anything else?

I did not see any reference in the documentation: https://codeigniter.com/user_guide/libraries/validation.html#setting-rules-for-array-data
I did not find any issue like this (maybe in the closed issues).

[kenjis]

Thank you for reporting. I've confirmed the behavior.
Yes, it seems the Validation class validates only the existing key field.

[ping-yee]

@kenjis You can assign me to handle this bug.

[kenjis]

@ping-yee Assigned.
The current code only performs processing on existing data. If the key is not present, it will not be processed. So it seems to me that we need to add a key that does not exist.

[ping-yee]

Yah, I just figure out how the current code works.

So it seems to me that we need to add a key that does not exist.

I will follow this way to fix this bug.

[kenjis]

@ping-yee Any progress?

[ping-yee]

@kenjis Yah, but this is not very optimistic and I need your help.
Or I send a draft PR first.

[kenjis]

I think this is very difficult problem. So it requires more brains.

[ping-yee]

I think this is very difficult problem. So it requires more brains.

Yes, I agree with this and I send the draft PR.

[kenjis]

As a workaround, you can use field_exists since v4.5.0.