--tasks.js

router.get('/', async (req, res) => {
  const task = await Task.find().sort('taskName');
  res.send(task.filter(p => p.userID == req.cookies['userID']));
});

-- auth.js
router.post('/', async (req, res) => {
    const { error } = validate(req.body);
    if (error) return res.status(400).send(error.details[0].message);

    let user = await User.findOne({ email: req.body.email });
    if(!user) return res.status(400).send('Invalid email or password.');

   const validPassword = await bcrypt.compare(req.body.password, user.password)
   if(!validPassword) return res.status(400).send('Invalid email or password.');

   const token = user.generateAuthToken();
   res.cookie("userID", req.body.email);
   res.cookie('x-auth-token', token);
   res.redirect("/");
});


router.get('/logout', async (req, res) => {
  res.clearCookie("x-auth-token");
  res.clearCookie("userID");
  res.redirect("/");
});

--taske.js
$( document ).ready(async function() {
    var tasks = [];
    var  response = await fetch('http://localhost:3000/api/tasks');
    $("#userID").val(getCookie("userID"));
    var result = await response.json();
    for(var i = 0; i < result.length; i++)
    {
        var stringParse = '<a href="#" onclick="editTask(' + '123' + ')">Edytuj</a>';
        var row = $("<tr/>");
        $("#taskTable").append(row);
        row.append($("<td>" + result[i]._id + "</td>"));
        row.append($("<td>" + result[i].taskName + "</td>"));
        row.append($("<td>" + result[i].taskDescription + "</td>"));
        stringParse = 'editTask(\'' + result[i]._id + '\',\'' + result[i].taskName + '\',\'' + result[i].taskDescription + '\')';
        console.log('<td>' + '<a href="#" onclick="' + stringParse + ';">Edytuj</a>' + '</td>');
        row.append('<td>' + '<a href="#" onclick="' + stringParse + '">Edytuj</a> | <a href="/api/tasks/delete/' + result[i]._id + '">Usuń</a>' + '</td>');
    }
});

--task.html
<form id="myForm" action="http://localhost:3000/api/tasks/" method="post">
    <input type="text" id="taskName" name="taskName" placeholder="Dodaj tytył">
    <input type="text" id="taskDescription" name="taskDescription" placeholder="Dodaj zadanie">
    <input type="hidden" id="userID" name="userID">
    <button type="submit">Zapisz</button>
</form>

--task.js {model}

const config = require('config');
const Joi = require('joi');
const mongoose = require('mongoose');

const taskSchema = new mongoose.Schema({
    taskName: {
      type: String,
      required: true,
      minlength: 5,
      maxlength: 50
    },
    taskDescription: {
        type: String,
        required: true,
        minlength: 5,
        maxlength: 1024,
      },
      userID: {
        type: String,
        required: true,
        minlength: 5,
        maxlength: 1024,
      },
    isDone: Boolean
  });

const Task = mongoose.model('Task', taskSchema);


function validateTask(task) {
  const schema = {
    taskName: Joi.string().min(5).max(50).required(),
    taskDescription: Joi.string().min(5).max(1024).required(),
    userID: Joi.string().min(5).max(1024).required()
  };

  return Joi.validate(task, schema);
}

exports.Task = Task;
exports.validate = validateTask;