[13.x] Fix TypeError in digits_between validation rule on non-string values

[sumaiazaman]

Summary

This PR fixes a TypeError thrown by the digits_between validation rule when a non-string, non-numeric value (such as an array) is passed. The rule calls preg_match() directly on the value without first checking its type, causing PHP 8 to throw a TypeError instead of returning a clean validation failure.

Context

Several validation rules have already received this same fix:

Rule	TypeError on non-string input	Fixed
starts_with	Str::startsWith() type-hint	✅ (merged in #59541)
ends_with	Str::endsWith() type-hint	✅ (merged in #59541)
doesnt_start_with	Str::startsWith() type-hint	✅ (merged in #59541)
doesnt_end_with	Str::endsWith() type-hint	✅ (merged in #59541)
lowercase	Str::lower() type-hint	✅ (merged in #59541)
uppercase	Str::upper() type-hint	✅ (merged in #59541)
ascii	Str::isAscii()	✅ (merged in #59541)
hex_color	preg_match() on array	✅ (merged in #59541)
max_digits	preg_match() on array	✅ (merged in #59541)
min_digits	preg_match() on array	✅ (merged in #59541)
digits	preg_match() on array	✅ (guarded inline)
digits_between	preg_match() on array	❌

digits_between is the only remaining rule in this family without a type guard. Its sibling digits is protected by an inline check — digits_between was simply missed.

Solution

Added the same is_string / is_numeric guard used in max_digits and min_digits:

if (! is_string($value) && ! is_numeric($value)) {
    return false;
}

Example

// Before: throws TypeError
$v = validator(['count' => ['a', 'b']], ['count' => 'digits_between:1,5']);
$v->passes(); // TypeError: preg_match(): Argument #2 ($subject) must be of type string

// After: returns a clean validation failure
$v->passes(); // false

Why This Doesn't Break Existing Features

• Non-string, non-numeric values were already expected to fail digits_between — now they fail cleanly instead of throwing
• All existing passing and failing cases for string and numeric input are unaffected
• The fix is identical to the guard already used in max_digits, min_digits, and implicitly in digits

Changes

• src/Illuminate/Validation/Concerns/ValidatesAttributes.php — Added type guard to validateDigitsBetween()
• tests/Validation/ValidationValidatorTest.php — Added array assertion to testValidateDigits() and a dedicated testValidateDigitsBetweenDoesNotThrowOnNonStringValue() test

Test Plan

• testValidateDigitsBetweenDoesNotThrowOnNonStringValue — Verifies array input returns false instead of throwing TypeError
• testValidateDigits — Existing test updated with array case for digits_between
• Existing tests pass (no breaking changes)