Block editors annoying warnings

I’ve made a page where the user can check the supported post formats, and the problem was that in case the user haven’t checked any post format it returns false, and instead of returning an array that contains ‘standard’ like the following return ['standard'], I used only the keyword return to stop the function from running.

Here is what I am talking about:

function get_supported_post_formats(){
    $options = get_option('post-supports-handler');

    if (empty($options)) {
        return ['standard'];
    }

    $formats = [
        'standard',
        'aside',
        'gallery',
        'link',
        'image',
        'quote',
        'video',
        'status',
        'audio',
        'chat',
    ];

    $output = [];

    foreach ($formats as $format) {
        $output[] = (@$options[$format] == '1' ? $format : '');
    }

    return $output;
}


$output = get_supported_post_formats();


add_theme_support('post-formats', $output);