estree-walker

What is estree-walker?

The estree-walker package is a simple utility for walking an ESTree-compliant AST (Abstract Syntax Tree), such as those produced by parsers like Acorn or Esprima. It allows users to traverse the tree and manipulate nodes during the traversal.

What are estree-walker's main functionalities?

Walking an AST

This feature allows you to traverse an AST, performing actions when entering and leaving each node. The 'enter' function is called when a node is entered, and the 'leave' function is called when a node is left during the traversal.

const { walk } = require('estree-walker');

const ast = { /* some AST object */ };

walk(ast, {
  enter(node, parent, prop, index) {
    // Perform actions upon entering a node
  },
  leave(node, parent, prop, index) {
    // Perform actions upon leaving a node
  }
});

Manipulating Nodes

This feature demonstrates how you can manipulate nodes during traversal. In this example, numeric literal values are doubled.

const { walk } = require('estree-walker');

const ast = { /* some AST object */ };

walk(ast, {
  enter(node) {
    if (node.type === 'Literal' && typeof node.value === 'number') {
      node.value *= 2; // Double the number
    }
  }
});

Other packages similar to estree-walker

acorn-walk

Acorn-walk is a small, fast, JavaScript-based AST walker for the Acorn parser. It provides similar functionality to estree-walker but is specifically designed to work with the ASTs generated by Acorn.

babel-traverse

Babel-traverse is part of the Babel toolchain and allows for traversing and manipulating Babel-generated ASTs. It offers a more complex API and additional features compared to estree-walker, such as scope tracking and path manipulation.

recast

Recast provides AST traversal and manipulation capabilities, as well as source map support and pretty-printing of the modified code. It is more feature-rich than estree-walker and integrates with the Esprima parser.

README

The README file is missing

Changelog

0.2.1

• Keep context shape