Add support for dynamic return type in WP_List_Table methods

[lipemat]

Introduce a T @template in the WP_List_Table class to allow reducing the return type of many methods to the actual array or object shape used in the class.

The code changes introduce support for dynamic return types in several methods of the WP_List_Table class. This allows for more flexibility in the return values based on the generic type T defined in the class.

[szepeviktor]

Thank you!

I wait for a review.

[herndlm]

a type inference test case, showing that this works and keeps working, would be great I guess? :)

[IanDelMar]

Please see https://phpstan.org/r/6f50bc44-c7db-41a7-b382-bca65c6332ec

Parameter $item of method WP_Privacy_Requests_Table::column_cb() has invalid type WP_User_Request.

[lipemat]

I finished your example which passes at level 9.

Just needed the class to exist and the generic to be passed.

Technically works without the generic passed but not at level 9.

https://phpstan.org/r/4c23cb5c-566c-4038-8ac6-440955dcd0a2

[szepeviktor]

I think key-of<> does not work with an object.
https://phpstan.org/writing-php-code/phpdoc-types
What do you think?

[lipemat]

I forget to mention the WP_List_Class also has an $items property which would benefit from a T[] type.

I couldn't figure out how to add a custom type to a property with the existing generate system and could use some help.

[szepeviktor]

WP_List_Table is an anti-everything tragedy.

[lipemat]

WP_List_Table is an anti-everything tragedy.

Agreed. The more I think about this the more it seems like I may be trying to narrow something down beyond how something is actually used.

In projects under our control we can determine the column names will match a key in the item, but in real world the column name could be anything.

We may have to let this one go in favor of project specific overrides. 🤷‍♂️

[szepeviktor]

How about dropping |object? Does any decent code uses an object?

[IanDelMar]

I forget to mention the WP_List_Class also has an $items property which would benefit from a T[] type.

I couldn't figure out how to add a custom type to a property with the existing generate system and could use some help.

Could this be achieved with the following addition?

class WP_List_Table {
    /**
     * @phpstan-assert $this->items T[]
     */
    public function prepare_items() {}
}

How about dropping |object? Does any decent code uses an object?

WP_Post_List_Table uses items of type WP_Post.

[szepeviktor]

How about dropping |object? Does any decent code uses an object?

WP_Post_List_Table uses items of type WP_Post.

I mean from template T only.
Does anyone uses objects there?

[IanDelMar]

WP_Post_List_Table.

See for example https://github.com/WordPress/wordpress-develop/blob/9d11cee11e7d2d01101fbe0fd6d8f03634021c8c/src/wp-admin/includes/class-wp-posts-list-table.php#L1011-L1019

[szepeviktor]

If I would be a programmer I would definitely use a straight-forward OOP wrapper.

[lipemat]

I solved the requirements by making the following changes:

1. Introduce a second template K to be used for the column names.
2. Update the $column_name parameters and get_columns return to use K instead of key-of<T>.

See it in action here.
https://phpstan.org/r/a4104203-bd28-459c-aff5-27715708acbe

[szepeviktor]

Guys! Could you try it in a project that is affected?