npm i estree-walker
var walk = walk;var acorn = ;ast = acorn; //;
enter function, calling
this.skip() will prevent the node's children being walked, or the
leave function (which is optional) being called.
Why not use estraverse?
The ESTree spec is evolving to accommodate ES6/7. I've had a couple of experiences where estraverse was unable to handle an AST generated by recent versions of acorn, because it hard-codes visitor keys.
estree-walker, by contrast, simply enumerates a node's properties to find child nodes (and child lists of nodes), and is therefore resistant to spec changes. It's also much smaller. (The performance, if you're wondering, is basically identical.)
None of which should be taken as criticism of estraverse, which has more features and has been battle-tested in many more situations, and for which I'm very grateful.