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

let todoFunctions = {
    // todoFunctions.generateId() will give you a unique id
    // You do not need to understand the implementation of this function.
    generateId: (function () {
        let 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 newObject = {
            id: todoFunctions.generateId(),
            description: newTodo,
            done: false
        };



        return todoFunctions.cloneArrayOfObjects(todos).concat(newObject);
        // should leave the input argument todos unchanged (you can use cloneArrayOfObjects)
        // returns a new array, it should contain todos with the newTodo added to the end.
        // add an id to the newTodo. You can use the generateId function to create an id.
        // hint: array.concat
    },
    deleteTodo: function (todos, idToDelete) {
        return todoFunctions.cloneArrayOfObjects(todos).filter(function (item) {
            return item.id !== idToDelete
        });
        // 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) {
        return todoFunctions.cloneArrayOfObjects(todos).map(function (item) {
            if (item.id === idToMark) {
                console.log(typeof(item.done));
                item.done = !item.done;
                return item;
            }
            else {
            return item;
          }
        });

        // 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
    },
};

// console.log(todoFunctions.addTodo());




// 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;
}