GildedRose

How to build

Open the solution in Visual Studio 2015, then Rebuild All. You can run the tests from whatever test tool you are using (I used ReSharper 2015).

How to run

The WebServices project uses IISExpress, so it's easiest to run from Visual Studio:

• From the solution properties, choose multiple startup projects:
  • GildedRose.IdentityServer
  • GildedRose.WebServices
• Start the solution.
• Run the GildedRose.ConsoleClient.exe from the command line (ConsoleClient\bin\Debug).
• Run it multiple times to see what happens to the inventory as you buy items.

Design decisions

• My current team has been using IdentityServer3 with good results, so I thought it would be an interesting exercise to apply it here. This implementation is all in-memory and represents the bare minimum implementation of IdentityServer3.
• I used a Service Layer to isolate business logic.
• I used a REST-type API, returning JSON (this is the easiest format for mobile and web teams to work with).
• I used an ItemEntity class for memory storage, and an additional Item class as a Model or DTO (Data Transfer Object). This provides an isolation layer between the Web API and the Storage layer. When retrieving data, the Service layer converts from an Entity (which may later represent an actual database object) to a simple Model. In this case the advantages are subtle, but later, when more data operations are supported, the advantages become clearer.

Choice of data format

As in Design Decisions above, I used Json for the data format, which will support the majority of downstream clients.

Sample request:

To get the list of items, just hit this URL:

http://localhost:14869/Inventory

###Sample response:

[{"Id":"746E4CFB-7DF8-46BC-9A94-923F29D17907","Name":"CSY 37","Description":"37 foot cutter-rigged 
sloop","Price":40000,"InventoryCount":3},{"Id":"2552E1C7-64C5-460F-B550-60F3A720033F","Name":"Venture
 24","Description":"24 foot swing keel","Price":5000,"InventoryCount":10}]

How do we know if a user is authenticated?

The BuyItem method on the Inventory Controller sports the [Authorize] attribute, which requires that a valid JWT (Json Web Token) is supplied in the HTTP headers for that method. This behavior is configured in the Startup class.

Is it always possible to buy an item?

Once the inventory count reaches zero, you can no longer buy an item. This logic is specified in the Service Layer.

Notes

ReSharper and StyleCop

I used my existing ReSharper and StyleCop settings, which use some non-default settings, such as allowing tabs instead of spaces and enforcing the use of "this". StyleCop was implemented using the StyleCop.Analyzers NuGet package, and was enforced by setting the Warnings as Errors build setting.

Integration Tests

I provided some unit tests, but didn't have to time to set up integration tests. Instead, the Console app demonstrates integration.

Boats

Oh, I should at least mention the sample data. They are makes and models of sailing boats!

Comments

My solution is a very basic example of an inventory system. A more realistic solution must take into account a number of other factors, such as multiple stores and geographic regions, multiple colors or sizes, time of year, sales, and special promotions.

If I had more time, I would:

• Add logging
• Add more exception handling
• Provide sample JavaScript code. This is useful for illustrating Ajax calls and Json formats to downstream teams.