isDirty not working for json object

[vsg24]

• Laravel Version: 8.83.16
• PHP Version: 8.0
• Database Driver & Version: mySQL 8.0

Description:

I'm trying to detect if an object is changed after the value of a property of a json field is updated. However, It's not detecting the change if the new value is a number with leading zeros. Note that the number is saved as a string so technically there shouldn't be any issues storing it along with all of its zeros.

Steps To Reproduce:

The aim is to update a property (account_number) of bban field (json object) on the $bankAccount object.
The code responsible for updating the values:

// dump the original value
dump($bankAccount->bban);
// update the json object
$bankAccount->bban = $this->dto->getBban();
// dump the updated value
dump($bankAccount->bban);
            
if ($bankAccount->isDirty(['bban'])) {
    // NEVER HITS!
    dd('values updated');
}

The result of dumping the json variable bban before and after the update:

As can be seen, the value is updated however the isDirty method isn't able to detect the change, as a result, dd('values updated'); is never executed.

It only fails when the new value has leading zeros. Also worth noting is that I am casting the bban field to json as it is the recommended approach.

protected $casts = [
    'bban' => 'object',
];

[rodrigopedra]

This seems to be fixed by #41337

But that PR was only sent to 9.x. If maintainers consider this a bug fix, can you send a PR backporting it to 8.x?

---

EDIT, as a workaround, casting to json seems to work:

class BankAccount extends Model
{
    protected $casts = ['bban' => 'json'];
}

[vsg24]

@rodrigopedra Thank you, I do want to create a PR to fix it for 8.x as well.

[vsg24]

@rodrigopedra PR created. #42793