Hey!

I see that this is your first PR. That is great! Welcome!

Symfony has acontribution guide which I suggest you to read.

In short:

• Always add tests
• Keep backward compatibility (seehttps://symfony.com/bc).
• Bug fixes must be submitted against the lowest maintained branch where they apply (seehttps://symfony.com/releases)
• Features and deprecations must be submitted against the 5.4 branch.

Review the GitHub status checks of your pull request and try to solve the reported issues. If some tests are failing, try to see if they are failing because of this change.

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I am going to sit back now and wait for the reviews.

Cheers!

Carsonbot

Which transport are you using ?

firebase - Symfony\Component\Notifier\Bridge\Firebase
and when the response comes null, then in the logs appears warning that the unknown index 'message_id', and then a critical error that the parameter cannot be null
$sentMessage->setMessageId($success['results'][0]['message_id']);
you can try to check for the existence of id in the response, if it does not exist, then pass an empty string to setMessageId. Maybe it will be better

Yes please check and only call setMessageId in the Firebase transport if it's a string

i can modify Symfony\Component\Notifier\Bridge\Firebase\FirebaseTransport.php
and check something like that
$sentMessage->setMessageId(isset($success['results'][0]['message_id']) ? : '');
and then make pull request

I saw that you removed your fork.
Please submit the PR again when you're ready, and please take time to properly fill in the PR template, the commit message, add a test case if possible also.
Thanks.

@dima-gr Your suggestion is indeed the fix that I would like to see.