const mongoose = require("mongoose");
const Schema = mongoose.Schema;

const userScheme = new Schema({
    name: String,
    age: Number
});

mongoose.connect("mongodb://localhost:27017/my", { useNewUrlParser: true });

const User = mongoose.model("User", userScheme);
const user = new User({
    name: String,
    age: Number
});

// проблема
function CheckCount(): string {
    let my: string = "";
     User.count({}, function test(err: any, docs: string){
       // mongoose.disconnect();

       // if(err) return console.log(err);

       // console.log(docs);
      //  return docs;
        my = docs;
        console.log(my);
    });
    console.log(my);
    return my;
}

console.log(CheckCount());

// работает
User.count({}, function(err: any, docs: any){
    mongoose.disconnect();

    if(err) return console.log(err);

    console.log(docs);
});