How to add data to JSON file so it is readable with NodeJS?

Question

JavaScript

I have a JSON file with this entry (for example):

{
  "user1": {
    "login": "abcde",
    "password": 12345
  }
}

How can I add another user there and change, for example, the login of the first one?
UPD. Decision:

var file = JSON.parse(fs.readFileSync('./renderer/file.json', 'utf-8'))
file.user1.password = 23456
fs.writeFileSync('./renderer/file.json', JSON.stringify(file, null, 2));

This code writes these lines to a JSON file (with formatting):

{
  "user1": {
    "login": "abcde",
    "password": 23456
  }
}

Answer 1

Read file, change data, write to file.