Issue #3497683 by grimreaper, pdureau, just_like_good_vibes: [2.0.0-rc2] Field formatter does not check empty field

Closes #3497683

modules/ui_patterns_field_formatters/src/Plugin/Field/FieldFormatter/ComponentFormatter.php

@@ -28,6 +28,9 @@ class ComponentFormatter extends ComponentFormatterBase {
    * {@inheritdoc}
    */
   public function viewElements(FieldItemListInterface $items, $langcode) {
+    if (count($items) === 0) {
+      return [];
+    }
     $context = $this->getComponentSourceContexts($items);
     $context['ui_patterns:lang_code'] = new Context(new ContextDefinition('any'), $langcode);
     $context['ui_patterns:field:items'] = new Context(new ContextDefinition('any'), $items);