logic.js

// Part 1. Fill in any missing parts of the todoFunction object!
// you can access these on todo.todoFunctions
// For part one we expect you to use tdd

var todoFunctions = {
  // todoFunctions.generateId() will give you a unique id
  // You do not need to understand the implementation of this function.
  generateId: (function() {
    var idCounter = 0;

    function incrementCounter() {
      return (idCounter += 1);
    }

    return incrementCounter;
  })(),
  
  //cloneArrayOfObjects will create a copy of the todos array 
  //changes to the new array don't affect the original
  cloneArrayOfObjects: function(todos) {
    return todos.map(function(todo){ 
      return JSON.parse(JSON.stringify(todo));
    });
  },
  
  addTodo: function(todos, newTodo) {
    let todoCopy = this.cloneArrayOfObjects(todos);
    var newObject = new Object();
    newObject.id = this.generateId();
    newObject.description = newTodo;
    newObject.done = false;
    console.log(newObject);
    console.log(todoCopy);
    return todoCopy.concat(newObject);
    },

    deleteTodo: function(todos, idToDelete) {
      var newArray = todoFunctions.cloneArrayOfObjects(todos).filter(x => x.id !== idToDelete);
      return newArray;
    // should leave the input argument todos unchanged (you can use cloneArrayOfObjects)
    // return a new array, this should not contain any todo with an id of idToDelete
    // hint: array.filter
  },
    
    
    // should leave the input argument todos unchanged (you can use cloneArrayOfObjects)
    // return a new array, this should not contain any todo with an id of idToDelete
    // hint: array.filter
  markTodo: function(todos, idToMark) {
    var newTodos = todoFunctions.cloneArrayOfObjects(todos);
    for (let item of newTodos) {
      if (item.id === idToMark) {
        item.done ? (item.done = false) : (item.done = true);
        return newTodos;
      }
    }
  },

    // should leave the input argument todos unchanged (you can use cloneArrayOfObjects)
    // in the new todo array, all elements will remain unchanged except the one with id: idToMark
    // this element will have its done value toggled
    // hint: array.map

  sortTodos: function(todos, sortFunction) {
    // stretch goal! Do this last
    // should leave the input arguement todos unchanged (you can use cloneArrayOfObjects)
    // sortFunction will have same signature as the sort function in array.sort
    // hint: array.slice, array.sort
  },
};

// Why is this if statement necessary?
// The answer has something to do with needing to run code both in the browser and in Node.js
// See this article for more details: 
// http://www.matteoagosti.com/blog/2013/02/24/writing-javascript-modules-for-both-browser-and-node/

if (typeof module !== 'undefined') {
  module.exports = todoFunctions;
}