Description

This PR fixes a bug withingroupBy in collections. I understand it can be considered as a breaking change in 12.x, so maybe worth to consider to fix this issue in 13.x

How to reproduce

Prepare an array with some values, for demoing reasons, it's easier to spot the bug withpreserveKeys: true enabled.

collect([10 => [],20 => ['user' =>2,'roles' => []],// missing30 => ['user' =>3,'roles' => [null]],40 => ['user' =>4,'roles' => ['Role_2']]])->groupBy('roles', preserveKeys:true)  ->dump();

The output after grouping missing key20, because of roles is an empty array, while key30 is an array with a single value ofnull.

Solution

InsidegroupBy function, treat any empty array returned as a grouping key tonull before processing. This ensures that items with an empty array are grouped under the “null” bucket rather than being skipped.