visitor

walk and transform ASTs with references to parent nodes

This module is heavily inspired by astw, falafel and acorn. It allows to walk and update ASTs providing references to parent nodes.

examples

var visit = require("visitor");
var assert = require("assert");

visit("var xs = [1, 2, 3];", {
  ArrayExpression: function (node) {
    assert.equal(node.source(), "[1, 2, 3]");
    assert.equal(node.parent.type, "VariableDeclarator");
    assert.equal(node.parent.parent.type, "VariableDeclaration");
  }
});

var visit = require("visitor");
var assert = require("assert");

var result = visit("1 + 2", {
  BinaryExpression: function (node) {
    if (node.operator === "+" &&
        node.left.type === "Literal" &&
        node.right.type === "Literal") {
      node.update(node.left.value + node.right.value);
    }
  }
});

assert(result === "3", "combined both sides of the expression");

install

With npm do:

npm install visitor

license

MIT