replace specified node in json

test.ts

import MagicString from 'magic-string';
import * as acorn from 'acorn';

const prefix = `const x=`;
const code = `${prefix}{
  "pages": ["pages/index/index"],
  "subpackages": [
    {
      "name": "A",
      "pages": ["innerModule/pages/index/index"]
    },
    {
      "name": "B",
      "pages": ["innerModule/pages/index/index"]
    }
  ]
}`;

const newNode = {
  name: `A`,
  pages: [`new/path`],
};

const ast: any = acorn.parse(code, { ecmaVersion: 'latest' });
const subpackagesNodes: any[] =
  ast.body[0].declarations[0].init.properties[1].value.elements;

const targetNode = subpackagesNodes.find(
  (n) => n.properties[0].value.value == 'A',
);

const ms = new MagicString(code);

if (targetNode) {
  const nameNode = targetNode.properties[0].value;
  const pagesNode = targetNode.properties[1].value;
  ms.update(nameNode.start, nameNode.end, JSON.stringify(newNode.name));
  ms.update(pagesNode.start, pagesNode.end, JSON.stringify(newNode.pages));
  console.log(ms.toString().substring(prefix.length));
}
// output
// {
//   "pages": ["pages/index/index"],
//   "subpackages": [
//     {
//       "name": "A",
//       "pages": ["new/path"]
//     },
//     {
//       "name": "B",
//       "pages": ["innerModule/pages/index/index"]
//     }
//   ]
// }