How to change object keys in deeply nested object with lodash?

Question

I have a following kind of object:

{
  options: [
    { id: 1, value: 'a' }
  ],
  nestedObj: {
    options: [
      { id: 2, value: 'b' }
    ]
  }
}

How do I change the key 'id' on both, options array in first level and in the nested level? I have tried to use lodash for this but not have been able to get the desired result:

{
  options: [
    { newKey: 1, value: 'a'
  ],
  nestedObj: {
    options: [
      { newKey: 2, value: 'b' }
    ]
  }
}

So I would like to find a function which works like lodash mapKeys but would iterate through deep nested object.

Answer 1

You can use _.transform() recursively to replace keys:

var obj = {
  options: [{
    id: 1,
    value: 'a'
  }],
  nestedObj: {
    options: [{
      id: 2,
      value: 'b'
    }]
  }
};

console.log(replaceKeysDeep(obj, {
  id: 'newKey',
  options: 'items'
}));

function replaceKeysDeep(obj, keysMap) { // keysMap = { oldKey1: newKey1, oldKey2: newKey2, etc...
  return _.transform(obj, function(result, value, key) { // transform to a new object

    var currentKey = keysMap[key] || key; // if the key is in keysMap use the replacement, if not use the original key

    result[currentKey] = _.isObject(value) ? replaceKeysDeep(value, keysMap) : value; // if the key is an object run it through the inner function - replaceKeys
  });
}

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