Attach data attributes through styles

+++ b/paragraphs_collection.module
@@ -90,3 +91,29 @@ function paragraphs_collection_themes_uninstalled($themes) {
+ */
+function paragraphs_collection_preprocess_paragraph(array &$variables) {
+  /** @var ParagraphInterface $paragraph */
+  $paragraph = $variables['paragraph'];
+  $paragraph_styles = $paragraph->getBehaviorSetting('style', 'styles', FALSE);
+
+  $all_styles = \Drupal::service('paragraphs_collection.style_discovery')->getStyles();
+
+  if ($paragraph_styles) {
+    foreach ($paragraph_styles as $paragraph_style) {
+      if (array_key_exists($paragraph_style, $all_styles) && array_key_exists('attributes', $all_styles[$paragraph_style])) {
+        if (!empty($all_styles[$paragraph_style]['attributes'])) {
+          $style_attributes = $all_styles[$paragraph_style]['attributes'];
+          foreach ($style_attributes as $attribute) {
+            foreach ($attribute as $attribute_key => $attribute_value) {
+              $variables['attributes'][$attribute_key] = $attribute_value;
+            }
+          }
+        }
+      }

we can add it directly in the plugin, where we have all information already.

Yes, that looks good now, but we should have a test for this, extend one of the existing test styles with some attributes and assert they are added.

Nice.