CodeIgniter4: Bug: "integer" validation rule 500 error

PHP Version

8.1

CodeIgniter4 Version

4.2.5

CodeIgniter4 Installation Method

Manual (zip or tar.gz)

Which operating systems have you tested for this bug?

Linux

Which server did you use?

apache

Database

No response

What happened?

The validation rule “integer” fail as 500 error as below

{
    "title": "TypeError",
    "type": "TypeError",
    "code": 500,
    "message": "CodeIgniter\\Validation\\FormatRules::integer(): Argument #1 ($str) must be of type ?string, array given, called in /var/www/src/system/Validation/Validation.php on line 314",
    "file": "/var/www/src/system/Validation/FormatRules.php",
    "line": 132,
    "trace": [
        {
            "file": "/var/www/src/system/Validation/Validation.php",
            "line": 314,
            "function": "integer",
            "class": "CodeIgniter\\Validation\\FormatRules",
            "type": "->",
            "args": [
                [],
                null
            ]
        },
        {
            "file": "/var/www/src/system/Validation/Validation.php",
            "line": 163,
            "function": "processRules",
            "class": "CodeIgniter\\Validation\\Validation",
            "type": "->",
...

That validation allows string numeric (not integer) as well

Steps to Reproduce

Validation rule used

protected $validationRules = [
        'integerAcceptsStringNumeric' => 'integer',
        'integerArrayError' => 'integer',
];

Data to validate

$data = [
        'integerAcceptsStringNumeric' => '1',
        'integerArrayError' => [],
];

Expected Output

Validation fail and return 400 if the value is not an integer

Anything else?

No response