Issue #3230593: Textarea's form errors are hidden

bootstrap_barrio.theme

@@ -715,3 +715,24 @@ function bootstrap_barrio_preprocess_input(&$variables) {
     $variables['safe_value_label'] = Xss::filter($variables['attributes']['value']);
   }
 }
+
+/**
+ * Implements hook_preprocess_textarea() for adding classes to textareas.
+ *
+ * hook_preprocess_input() hook does not launched for textareas.
+ */
+function bootstrap_barrio_preprocess_textarea(&$variables) {
+  if (isset($variables['attributes']['class'])) {
+    if (is_object($variables['attributes']['class'])) {
+      if (in_array('error', $variables['attributes']['class']->value())) {
+        $variables['wrapper_attributes']->addClass('is-invalid');
+      }
+    }
+    elseif (is_array($variables['attributes']['class'])) {
+      if (in_array('error', $variables['attributes']['class'])) {
+        $variables['wrapper_attributes']['class'][] = 'is-invalid';
+      }
+    }
+  }
+}
+