Javascript – Push elements to array in mongoose while keeping all the other element in the array

Problem:

I have the following two schemas:

Blog Schema:

const blogSchema = new mongoose.Schema(
  {
    title: { type: String, min: 3, max: 20, required: true },
    content: { type: String, required: true },
    likes: { type: Number, required: true, default: 0 },
    author: { type: mongoose.SchemaTypes.ObjectId, ref: "User" },
    comments: [
      { type: mongoose.SchemaTypes.ObjectId, ref: "Comment", default: [] },
    ],
  },
  { timestamps: true, collection: "blogs" }
);

User Schema:

const userSchema = new mongoose.Schema(
  {
    name: { type: String, min: 3, max: 20, required: true },
    email: { type: String, required: true, unique: true },
    password: { type: String, min: 3, max: 50, required: true },
    blogs: [
      {
        type: mongoose.SchemaTypes.ObjectId,
        type: String,
        ref: "Blog",
        required: false,
        default: [],
      },
    ],
    comments: [
      {
        type: mongoose.SchemaTypes.ObjectId,
        type: String,
        ref: "Comment",
        required: false,
        default: [],
      },
    ],
  },
  { timestamps: true, collection: "users" }
);

When I add a new blog I want to update the blogs array in the user schema and add the new blog ID to it. I tried to do it like this:

const { title, content, author } = input;

const newBlog = await Blog.create({
  title: title,
  content: content,
  author: author,
});

let user = await User.findById(author);

await user.updateOne(
  { blogs: [...user.blogs] },
  { $push: { blogs: newBlog } }
);
await user.save();

console.log(newBlog);
return await newBlog.populate("author");

The blog gets added to the collection but the array in the user model doesn’t get updated.
If you have any suggestion please let me know.

Solution:

You can do this in one update statement by combining findByIdAndUpdate with $push. Update as follows:

const user = await User.findByIdAndUpdate(author,
   { 
      $push: {
         blogs: newBlog._id
      }
   },
   {new:true}
);

As an aside it appears you have some errors in your User schema. You are defining the type twice for blogs and comments here:

type: mongoose.SchemaTypes.ObjectId,
type: String,

This should just be left as type: mongoose.Types.ObjectId.