I'm trying to insert new data if the does not exist in the nested array, so far I'm able to add if they don't exist, but it's removing the previous data, any help would be appreciated.

Arrays

const posts = 
  [ { _id: 1
    , message: 'this is post one'
    , likes:    [ { id: 111221, user: 'random 1' } , { id: 2223422, user:'random 2' } ] 
    , comments: [ { id: 332233, message: 'random comment' } , { id: 2344444, message:'another random comment' } ] 
  }] 
const comments = 
  [ { id: 3333, message: 'this is comment 1' } 
  , { id: 4444, message: 'this is comment 2' } 
  ] 
const likes = 
  [ { id: 1111, user: 'Peter' } 
  , { id: 2222, user: 'John'  } 
  ] 

expected output

const newPost = 
  [ { _id: 1
    , message: 'this is post one'
    , likes:    [ 
        { id: 1111, user: 'Peter' } ,
        { id: 111221, user: 'random 1' } , 
        { id: 2223422, user:'random 2' } ,
        { id: 2222, user: 'John'  }
    ] 
    , comments: [ 
        { id: 3333, message: 'this is comment 1' } ,
        { id: 4444, message: 'this is comment 2' },
        { id: 332233, message: 'random comment' } , 
        { id: 2344444, message:'another random comment' } 
    ] 
  }] 

what I've tried

const newPosts = posts.map(post => ({
    ...post,
    likes: likes.filter(like => !post.likes.map(like => like.id).includes(like.id)),
    comments: comments.filter(comment => !post.comments.map(comment => comment.id).includes(comment.id)),
}))

console.log(newPosts)

CodePudding user response：

Perhaps I'm too tired, but I would just merge the arrays together. Your post didn't mention that you needed to check whether the comments in the variable comments already could exist in posts[0].comments (_id: 1).

const posts = [{
  _id: 1,
  message: 'this is post one',
  likes: [{
    id: 111221,
    user: 'random 1'
  }, {
    id: 2223422,
    user: 'random 2'
  }],
  comments: [{
    id: 332233,
    message: 'random comment'
  }, {
    id: 2344444,
    message: 'another random comment'
  }]
}]

const comments = [{
  id: 3333,
  message: 'this is comment 1'
}, {
  id: 4444,
  message: 'this is comment 2'
}]
const likes = [{
  id: 1111,
  user: 'Peter'
}, {
  id: 2222,
  user: 'John'
}]

const addTo = (posts, comments, likes) => {
  let newPostInstance = [...posts][0];
  
  newPostInstance.comments = [...newPostInstance.comments, ...comments];
  newPostInstance.likes    = [...newPostInstance.likes, ...likes];
  
  return newPostInstance;
}

const newPost = addTo(posts, comments, likes);

console.log(newPost)

<iframe name="sif1" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

CodePudding user response：

const posts1 = 
  [ { _id: 1
    , message: 'this is post one'
    , likes:    [ { id: 111222221, user: 'random 1' } , { id: 2223422, user:'random 2' } ] 
    , comments: [ { id: 3322222233, message: 'random comment' } , { id: 2344444, message:'another random comment' } ] 
  }] 


  const posts = 
  [ { _id: 1
    , message: 'this is post one'
    , likes:    [ { id: 111221, user: 'random 1asdasdasd' } , { id: 2223422, user:'random 2asdasdasd' } ] 
    , comments: [ { id: 332233, message: 'rasdasdasd' } , { id: 2344444, message:'asdasdasdwwwwww' } ] 
  }] 

if(posts.filter(r => r.comments) !== posts1.filter(r => r.comments)){
    const a = posts.map(({likes,_id,message, ...o}) => ({...o.comments}))
    const b = posts1.map(({likes,_id,message, ...o}) => ({...o.comments}))
    const c = posts.map(({comments,_id,message, ...o}) => ({...o.likes}))
    const d = posts1.map(({comments,_id,message, ...o}) => ({...o.likes}))

    const newComments = [...a,...b]
    const newLikes = [...c,...d]

    const returnFlattenObject = (arr) => {
        const flatObject = {};
        for(let i=0; i<arr.length; i  ){
           for(const property in arr[i]){
              flatObject[`${property}_${i}`] = arr[i][property];
           }
        };
        return flatObject;
    }

    posts.map(({comments,likes, ...o}) => ({
        ...o,
        comments: returnFlattenObject(newComments),
        likes: returnFlattenObject(newLikes)
    }))
} else {
    console.log('exists')
}

result

[{…}]
0:
comments:
0_0: {id: 332233, message: 'rasdasdasd'}
0_1: {id: 3322222233, message: 'random comment'}
1_0: {id: 2344444, message: 'asdasdasdwwwwww'}
1_1: {id: 2344444, message: 'another random comment'}
[[Prototype]]: Object
likes:
0_0: {id: 111221, user: 'random 1'}
0_1: {id: 111222221, user: 'random 1'}
1_0: {id: 2223422, user: 'random 2'}
1_1: {id: 2223422, user: 'random 2'}
[[Prototype]]: Object
message: "this is post one"
_id: 1
[[Prototype]]: Object
length: 1
[[Prototype]]: Array(0)