Feature request: _.deepFreeze

[toshisugimo]

Hi!

I want to add a new function _.deepFreeze to lodash.

Pure javascript Object.freeze() does not freeze nested object.

const user = {
  name: 'Taro',
  age: 24,
  email: 'foo@example.com',
  location: {
    country: 'Japan',
    city: 'Tokyo'
  }
}

Object.freeze(user);

user.location.city = 'Kyoto';
// This will work. Because nested objects are not frozen.

console.log(user.location.city);
//=> 'Kyoto'
// Change from 'Tokyo' to 'Kyoto'

The _.deepFreeze function I want to propose also freezes nested objects.

const user = {
  name: 'Taro',
  age: 24,
  email: 'foo@example.com',
  location: {
    country: 'Japan',
    city: 'Tokyo'
  }
}

_.deepFreeze(user);

user.location.city = 'Kyoto';
// This will not work. user.location is immutable!
// TypeErrors will occur here if in strict mode.

console.log(user.location.city);
//=> 'Tokyo'
// Not changed

What do everyone think?
Thank you very much!

[ashclarke]

Just a note of support as I have a custom implementation in place for this. There are probably better ways of doing it, but I have this:

function deepFreeze(object) {
    if (!_.isObjectLike(object)) {
        return;
    }

    Object.freeze(object);

    _.forOwn(object, function (value) {
        if (!_.isObjectLike(value) ||
            Object.isFrozen(value)) {

            return;
        }

        deepFreeze(value);
    });
}

[jdalton]

Hi @toshisugimo!

I think something like this would be good on its own or in a suite of utils for immutability. For a reference implementation you can check out deep-freeze-strict.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.