How to append $metadata['sizes'] to metadata when using 'wp_generate_attachment_metadata?

Question

When a file such as an image is uploaded, an optimized version is created with $saved = $editor->save($editor->generate_filename('name'));. This successfully writes the file to disk and the intermediate sizes are created too from the source/original image.

I'd like to add the optimized version to the array of sizes. I've tried the following but no additional size is added to the metadata array.

$metadata['sizes']['full'] = [];
$metadata['sizes']['full']['file'] = $saved['file'];
$metadata['sizes']['full']['width'] = $saved['width'];
$metadata['sizes']['full']['height'] = $saved['height'];
$metadata['sizes']['full']['mime-type'] = $saved['mime-type'];
$metadata['sizes']['full']['filesize'] = $saved['filesize'];

I've attempted $metadata['sizes'] = array('full' => $saved,); but again the 'full' size isn't added/appended to the list existing array.

How can I go about adding/pushing/merging it?

Answer 1

Although the suggested answer from admcfajn wasn't the solution to the problem/question, it did lead me to look explore it further. Thanks admcfajn.

Assuming you are using either the default intermediate e.g. thumbnail or custom sizes e.g. 320w and would like to include additional sizes such as full, you can use wp_update_attachment_metadata( $attachment_id, $metadata );