1 files changed, 45 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/util/traverser.js b/tools/node_modules/eslint/lib/util/traverser.js
new file mode 100644
index 0000000000..fc070186b3
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+++ b/tools/node_modules/eslint/lib/util/traverser.js
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+/**
+ * @fileoverview Wrapper around estraverse
+ * @author Nicholas C. Zakas
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const estraverse = require("estraverse");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+const KEY_BLACKLIST = new Set([
+    "parent",
+    "leadingComments",
+    "trailingComments"
+]);
+
+/**
+ * Wrapper around an estraverse controller that ensures the correct keys
+ * are visited.
+ * @constructor
+ */
+class Traverser extends estraverse.Controller {
+    traverse(node, visitor) {
+        visitor.fallback = Traverser.getKeys;
+        return super.traverse(node, visitor);
+    }
+
+    /**
+     * Calculates the keys to use for traversal.
+     * @param {ASTNode} node The node to read keys from.
+     * @returns {string[]} An array of keys to visit on the node.
+     * @private
+     */
+    static getKeys(node) {
+        return Object.keys(node).filter(key => !KEY_BLACKLIST.has(key));
+    }
+}
+
+module.exports = Traverser;