pug-walk

Walking the AST

This example demonstrates how to traverse a Pug template's AST to find all `div` tags and add an `id` attribute to them. The `walk` function takes the AST and a callback function that is applied to every node. If the node matches the criteria (a `div` tag in this case), a new attribute is added.

const pug = require('pug');
const pugWalk = require('pug-walk');

const ast = pug.parser.parse('div(class=classes)');
pugWalk.walk(ast, (node, replace) => {
  if (node.type === 'Tag' && node.name === 'div') {
    node.attrs.push({
      name: 'id',
      val: '"dynamic-id"',
      mustEscape: false
    });
    replace(node);
  }
});

Filtering Nodes

This code snippet shows how to filter nodes of a specific type, in this case, `Conditional` nodes, from a Pug template's AST. The `walk` function is used to traverse the AST, and nodes that match the specified condition are added to an array for further processing.

const pug = require('pug');
const pugWalk = require('pug-walk');

const ast = pug.parser.parse('div
  if condition
    p True
  else
    p False');
const filteredNodes = [];
pugWalk.walk(ast, node => {
  if (node.type === 'Conditional') {
    filteredNodes.push(node);
  }
}, {includeDependencies: true});