Alex's-Bookstore-API

This is a developer guide for Alex's Bookstore API developed as a writing assignment for FIS Global. This is a fictional API.

Overview

This describes the methods that will allow you to implement the shopping cart for Alex's bookstore. The API is designed to allow customers to choose books, add or remove them from their shopping cart, and checkout when they are done.

API Methods	Description
.addBook(book)	Adds an item to the cart. Params: string
.removeBook(book)	Removes an item from the cart. Params: string
.checkout()	Purchases the items in the cart. Returns: boolean
.list()	Returns the contents of the cart. Returns: array(string)

Programming Guidelines

Getting Started

A new user must be instantiated as a shopper for a shopping cart to be established for them.

const user = new AlexShopper();

Listing Items in the Cart

This method will return all books that have been added to the shopping cart as an array of book titles.

user.list();
// => ['BestSeller1', 'BestSeller2']

Adding a Book

This method adds a book to the shopping cart. The parameter is the title of the book being purchased. It returns the contents of the shopping cart as an array.

user.addBook('BestSeller1');
user.list();
// => ['BestSeller1']

Currently .addBook() is only able to add one title at a time to the shopping cart. Call the method again for each new item.

Removing a Book

This method will remove a book from the cart. The parameter is the title of the book being removed.

user.removeBook('BestSeller1');
user.list();
// => []

Checkout

This method will purchase all the books in the cart. This method returns true if the transaction is successful and the cart will become empty. Here is an example of a complete transaction:

const user = new AlexShopper();
user.addBook('BestSeller1');
user.addBook('BestSeller2');
user.addBook('FantasyFic');
user.list();
// => ['BestSeller1', 'BestSeller2', 'FantasyFic']

user.removeBook('Bestseller2');
user.list();
// => ['BestSeller1', 'FantasyFic']

user.checkout();
// => true

user.list();
// => []

Error Handling

This API will throw exceptions in the following conditions:

• if .removeBook is called on an empty cart
• if .checkout is called on an empty cart

Use a try/catch statement if you need to facilitate these exceptions.

try {
	const user = new AlexShopper();
	alex.checkout(); // throws new Error('Empty cart')
	
	alex.addBook('BestSeller1');
	alex.addBook('FantasyFic');
} catch(err) {
	console.log(err.message);
}

Diagram

Bookstore API Sequence Diagram in Gliffy