Improve code quality and write tests

node_modules/regexp-tree/dist/compat-transpiler/transforms/index.js

@@ -0,0 +1,17 @@
+/**
+ * The MIT License (MIT)
+ * Copyright (c) 2017-present Dmitry Soshnikov <dmitry.soshnikov@gmail.com>
+ */
+
+'use strict';
+
+module.exports = {
+  // "dotAll" `s` flag
+  dotAll: require('./compat-dotall-s-transform'),
+
+  // Named capturing groups.
+  namedCapturingGroups: require('./compat-named-capturing-groups-transform'),
+
+  // `x` flag
+  xFlag: require('./compat-x-flag-transform')
+};