Throw to be safer

src/KeyValueStore/DatabaseStorageExpirableToken.php

@@ -37,7 +37,11 @@ class DatabaseStorageExpirableToken extends DatabaseStorageExpirable {
     $token = preg_replace('/[^a-z0-9_-]/i', '', $token);
     $token = trim($token);
 
-    return empty($token) ? '' : sprintf('%%;s:13:"preview_token";s:%d:"%s";%%', strlen($token), $token);
+    if (empty($token)) {
+      throw new \InvalidArgumentException('Invalid token value.');
+    }
+
+    return sprintf('%%;s:13:"preview_token";s:%d:"%s";%%', strlen($token), $token);
   }
 
   /**
@@ -51,7 +55,6 @@ class DatabaseStorageExpirableToken extends DatabaseStorageExpirable {
    */
   public function getKeyByToken(?string $token) {
     try {
-      // Search for the token.
       $data = $this->connection->query(
         'SELECT [name], [value] FROM {' . $this->connection->escapeTable($this->table) . '} WHERE value LIKE :token AND collection = :collection',
         [