[12.x] Ensure Bus::chain filters out falsy items

[jackbayliss]

Bus::batch() does this - so feels natural (to me) that chain should too.. as it feels pointless keeping any null or empty values in the chain.

When it's serialized this should also help reduce the size - if anyone is currently doing this.

I've done this in prepareNestedBatches as it keeps the logic centralised. it also means append / prepend benefit from it too.

This means we can now do an inline chain like..

Bus::chain([
    new ProcessOrder($order),
    $order->needsShipping() ? new ShipOrder($order) : null,
    $order->isGift() ? new SendGiftMessage($order) : null,
    new SendConfirmationEmail($order),
])->dispatch();


Bus::assertChained(function (PendingChain $chain) {
    $jobs = array_filter($chain->jobs); // won't need to do this anymore.
    return count($jobs) === 2;
});

I think I've covered it in tests, but happy to target 13.x if this is a bit risky for 12.x

[github-actions]

Thanks for submitting a PR!

Note that draft PR's are not reviewed. If you would like a review, please mark your pull request as ready for review in the GitHub user interface.

Pull requests that are abandoned in draft may be closed due to inactivity.