--- /dev/null
+<?php
+
+namespace Drupal\filter_test\Plugin\Filter;
+
+use Drupal\filter\FilterProcessResult;
+use Drupal\filter\Plugin\FilterBase;
+
+/**
+ * Provides a test filter to associate cache tags
+ *
+ * @Filter(
+ * id = "filter_test_cache_tags",
+ * title = @Translation("Testing filter"),
+ * description = @Translation("Does not change content; associates cache tags."),
+ * type = Drupal\filter\Plugin\FilterInterface::TYPE_TRANSFORM_REVERSIBLE
+ * )
+ */
+class FilterTestCacheTags extends FilterBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function process($text, $langcode) {
+ $result = new FilterProcessResult($text);
+ $result->addCacheTags(['foo:bar']);
+ $result->addCacheTags(['foo:baz']);
+ return $result;
+ }
+
+}