Terrible Asynchronous API Exercise

A (terrible) legacy api exists for interacting with a stock system. It returns results asynchronously. The details of the API are included below, and should be generally correct. Using the API complete the following tasks:

1. Lookup the SKU and price, IN ORDER for an apple, a banana and an orange, printed in the format:

   Product: SKU: , Price:

   e.g.

    apple: SKU: a134, Price: 0.99

Remember, the outputted order must be: Apple, Banana, Orange, and it must be the same across multiple runs.

2. Create a new basket and add the following products (or the maximum available):

• 4 bananas

• 16 apples

  e.g. where there are only 3 bananas available, you would add only 3.

  At each point print out the quantity of the products added

  Then confirm the order, printing the returned order-code.

  The expected output should look similar to:

    Adding 3 banana
    Adding 16 apple
    Order confirmed: ORD-1234

API Documentation

Installation

To install the API:

npm install mj-legacy-api

In your code to create an instance of the API Client:

const ApiClient = require('mj-legacy-api');

const api = new ApiClient();

Lookup SKU

Product names will resolve to a Stock Keeping Unit. Prices and Stock can only be looked up against SKU, NOT name.

api.lookupSku(name, callback);

Parameters

• name: string, name of the product, case insensitive
• callback: function to call on lookup completion, function will be called with the parameters:
  • error - JS Error object, if successful, error will be undefined.
  • details - object with properties: sku (string)

Errors

On failure to locate product, an error with the message: PRODUCT_NOT_FOUND will be returned.

Lookup Price

api.lookupPrice(sku, callback);

Parameters

• sku: string, Product SKU, NOT product name
• callback: function to call on lookup completion, function will be called with the parameters:
  • error - JS Error object, if successful, error will be undefined.
  • details - object with properties: sku (string), price (float)

Errors

On failure to locate product, an error with the message: PRODUCT_NOT_FOUND will be returned.

Lookup Stock

api.lookupStock(sku, callback);

Parameters

• sku: string, Product SKU, NOT product name
• callback: function to call on lookup completion, function will be called with the parameters:
  • error - JS Error object, if successful, error will be undefined.
  • details - object with properties: sku (string), stock (integer)

Errors

On failure to locate product, an error with the message: PRODUCT_NOT_FOUND will be returned.

Create Basket

api.createBasket(sku, callback);

Parameters

• sku: string, Product SKU, NOT product name
• callback: function to call on basket creation, function will be called with the parameters:
  • error - JS Error object, if successful, error will be undefined.
  • basket - basket object (see below)

Errors

On failure to locate product, an error with the message: PRODUCT_NOT_FOUND will be returned.

Add Product to Basket

basket.add(sku, quantity, callback);

Parameters

• sku: string, Product SKU, NOT product name
• quantity: integer, number of products to add
• callback: function to call on operation completion, function will be called with the parameters:
  • error - JS Error object, if successful, error will be undefined.

Errors

On failure to locate product, an error with the message: PRODUCT_NOT_FOUND will be returned.

On insufficient stock, an error with the message: NOT_ENOUGH_STOCK will be returned.

Confirm Basket Order

basket.confirm(callback);

• callback: function to call on operation completion, function will be called with the parameters:
  • error - JS Error object, if successful, error will be undefined.
  • reference - string of the order reference