WordPress 合并样式/脚本文件，只加载一条

function wpunion_combine_assets($type = 'style') {
    if (WP_DEBUG || WU_DEVELOPMENT) return;

    $is_combine_style = $type === 'style';

    global $wp_styles, $wp_scripts;

    $obj = $is_combine_style ? $wp_styles : $wp_scripts;
    if (empty($obj->queue)) return;

    $base_dir = WP_CONTENT_DIR . '/wpunion-work/combined/';
    $base_url = content_url('/wpunion-work/combined/');
    if (!is_dir($base_dir)) wp_mkdir_p($base_dir);

    $excludes = ['xx'];                  //要排除的文件句柄
    $sources = [];                       // 用于生成唯一 hash
    $targets = [];                       // 将要合并的资源

    foreach ($obj->queue as $handle) {
        if (in_array($handle, $excludes)) continue;

        $reg = $obj->registered[$handle] ?? '';
        if (!$reg) continue;

        $src = $reg->src ?? '';
        if (!$src) continue;

        // 只处理本站资源
        if (strpos($src, home_url()) === false && strpos($src, get_stylesheet_directory_uri()) === false && strpos($src, get_template_directory_uri()) === false) continue;

        $path = str_replace(home_url('/'), ABSPATH, $src);
        $path = wp_normalize_path($path);

        if (file_exists($path)) {
            $sources[] = $src . $reg->ver ?? '';
            $targets[$handle] = $path;
        }
    }

    if (!$targets) return;
    $hash = md5(json_encode($sources));
    $ext = $is_combine_style ? '.css' : '.js';
    $filename = "wpunion-combined-{$hash}{$ext}";
    $filepath = $base_dir . $filename;
    $fileurl = $base_url . $filename;

    // 若合并文件不存在 → 生成
    if (!file_exists($filepath)) {
        $buffer = '';
        foreach ($targets as $handle => $path) {
            $buffer .= "\n/** wpunion combine {$handle} */\n" . file_get_contents($path);
        }
        file_put_contents($filepath, $buffer);
    }

    // 清除原有资源
    foreach ($targets as $handle => $path) {
        if ($is_combine_style) {
            wp_dequeue_style($handle);
            wp_deregister_style($handle);
        }
        else {
            wp_dequeue_script($handle);
            wp_deregister_script($handle);
        }
    }

    // 引入合并资源
    if ($is_combine_style) {
        wp_enqueue_style("wpunion-{$hash}", $fileurl, [], filemtime($filepath));
    }
    else {
        wp_enqueue_script("wpunion-{$hash}", $fileurl, [], filemtime($filepath), true);
    }
}

// 合并 CSS
add_action('wp_print_styles', function () {
    wpunion_combine_assets('style');
}, PHP_INT_MAX);

// 合并 JS
add_action('wp_print_scripts', function () {
    wpunion_combine_assets('script');
}, PHP_INT_MAX);