Implement tag filtering

src/Repository/SnipRepository.php

@@ -79,6 +79,13 @@ class SnipRepository extends ServiceEntityRepository
                 throw new \InvalidArgumentException('Invalid sort option: ', $request->sort);
         }
 
+        if ($request->tag) {
+            $qb->innerJoin('s.tags', 't')
+               ->andWhere('t.name = :tag')
+               ->setParameter('tag', $request->tag)
+            ;
+        }
+
         return $qb->getQuery()->getResult();
     }