Framework: Cannot use groupBy in API resource

[foremtehan]

• Laravel Version: 6
• PHP Version: 7.3
• Database Driver & Version: Mysql 5.7

Description:

When we use groupBy in api resources its class doesnt accept the key and we cannot modify the json:

public function toArray($request)
{
    return [
        'comments' => CommentResource::collection($this->comments->groupBy('someColumn')),
    ];
}

Property [someColumn] does not exist on this collection

Without using CommentResource it will work:

public function toArray($request)
{
    return [
        'comments' => $this->comments->groupBy('someColumn'),
    ];
}

But we cannot modify the comments columns in its json response and it returns all columns.

[devcircus]

When you call groupBy on the comments collection, you're not getting back a collection of models. You're getting back a collection of keys that contain a collection of models.

You could possibly group the collection once it has been created.
CommentResource::collection($this->comments)->collection->groupBy('someColumn')