mapping-keys v2.0.4

let comment = {
  comment_id: 42,
  user_id: 1024,
  user_name: 'Mufasa',
  content: 'You deliberately disobeyed me.',
  viewed_by: [
    { user_id: 3820, user_name: 'Rafiki' },
    { user_id: 8391, user_name: 'Zazu' }
  ]
};

function snakeToCamel(key) {
  return key.replace(/_(\w)/g, (match, char) => char.toUpperCase());
}

let result = mappingKeys(comment, snakeToCamel);

And the result will look like this:

{
  commentId: 42,
  userId: 1024,
  userName: 'Mufasa',
  content: 'You deliberately disobeyed me.',
  viewedBy: [
    { userId: 3820, userName: 'Rafiki' },
    { userId: 8391, userName: 'Zazu' }
  ]
}