how to traverse an AST with astray and collect identifier sources + references

astray-references.js

import * as astray from 'astray';
import { parse } from 'meriyah';

const AST = parse(`
	var intro = greeting();

	function greeting() {
		return 'Hello world!';
	}

	console.log('this is my intro:', intro);
	console.log('it should match:', greeting());
`);

const REFS = new Map;

astray.walk(AST, {
	Identifier(node, state) {
		let value = state.get(node.name) || {
			source: null,
			refs: []
		};

		let source = toParent(node);
		if (source && source.type === 'MemberExpression') return;
		if (source && /Declaration/.test(source.type)) value.source = source;
		else value.refs.push(source || node);

		state.set(node.name, value);
	}
}, REFS);

function toParent(node) {
	let parent = node;
	let RGX = /(Function|Variable)Declaration|Expression/;
	while (parent = parent.path.parent) {
		if (RGX.test(parent.type)) return parent;
	}
}

for (let [key, val] of REFS) {
	console.log(key, val);
}

output.txt

intro {
  source: {
    type: 'VariableDeclaration',
    kind: 'var',
    declarations: [ [Object] ],
    path: { parent: [Object] }
  },
  refs: [
    {
      type: 'CallExpression',
      callee: [Object],
      arguments: [Array],
      path: [Object]
    }
  ]
}
greeting {
  source: {
    type: 'FunctionDeclaration',
    id: { type: 'Identifier', name: 'greeting', path: [Object] },
    params: [],
    body: { type: 'BlockStatement', body: [Array], path: [Object] },
    async: false,
    generator: false,
    path: { parent: [Object] }
  },
  refs: [
    {
      type: 'CallExpression',
      callee: [Object],
      arguments: [],
      path: [Object]
    },
    {
      type: 'CallExpression',
      callee: [Object],
      arguments: [],
      path: [Object]
    }
  ]
}