MongoDB findOneAndUpdate doesn't return errors but also doesn't update the database

Question

I'm trying to use findOneAndUpdate() but can't seem to get it to work. Here's the query I'm using. It adds an object to an 'items' array nested inside of a 'lists' array for a particular entry with 'username'. I've tried it with a simple $set for a field not inside of a nested array, and it also doesn't seem to work. Currently no errors are being returned.

MongoClient.connect(
      uri,
      { useUnifiedTopology: true },
      (err, db) => {
        if (err) throw err;
        var dbo = db.db("Todolist");
        dbo.collection("Users").findOneAndUpdate(
          {
            username: username,
            lists: {
              $elemMatch: {
                name: listName,
              },
            },
          },
          {
            $push: {
              "lists.$.items": {
                title: title,
                description: description,
                dueDate: dueDate,
                priority: priority,
                completed: false,
              },
            },
          }
        );
      },
      (err, doc) => {
        if (err) res.send("/addListItem failed");
        else res.send("/addListItem successful");
      }
    );
  } catch (e) {
    console.error(e);
  }

Answer 1

You have to use .dot notation along with the $ positional operator here

Schema.findOneAndUpdate(
  { username: username },
  { "lists.$.name": listName }
)

Answer 2

It turned out that the answer to my problem was bracket placement. I placed the callback after the closing ) for the function arguments to findOneAndUpdate .