BlackJack by Ronak Shah
This contains the code for my Kleiner Perkins Coding Submission. Created by Ronak Shah
- How to Run | Setup
- How to Run | Actually Running It
- Decisions Made
- Code Structure
- Background and Disclaimer
This project is written in node.js and typescript. For your convenience, I have precompiled this project so the output javascript is there.
First, you'll need to get the project
git clone https://github.com/ronakdev/blackjack_ts
cd blackjack_ts
Or, if you don't have git
wget https://github.com/ronakdev/blackjack_ts/archive/master.zip
unzip master.zip
cd blackjack_ts-master/
To run this, you'll first need to install node (npm should install with it as well)
Using Homebrew, it's as simple as
brew install node
curl -sL https://deb.nodesource.com/setup_10.x | sudo -E bash -
sudo apt-get install -y nodejs
sudo apt-get install -y build-essential
Treehouse has a great guide on windows.
Don't worry, it's super simple to install! Follow this guide
Once you have node and npm installed, simply run npm start. If you run into issues, you may need to install the required packages (npm install)
npm start
Why Typescript?
In the background, I explain why I decided to revamp my old submission to properly demonstrate my coding abilities. Last year, I wrote a version of blackjack that didn't implement splitting (had some bugs) in pure javascript. This year, I wanted to make sure I submitted a complete game.
I knew I had wanted to use Typescript beforehand, after my mentor and boss from USDS suggested it after I mentioned to him my loven of Javascript. I can honestly say he was completely right - Typescript is quite fun to write with.
Styling
As part of running the student org ACM at UC San Diego, I assist the development team. Our development team strictly adheres to Google's JS Style Guide, which I initially fought heavily against. (I'm a fan of 4 spaces, not 2). I eventually realized the benefits of a style consistency, and have thus used Google's Typescript Linter in this project
In building this, I decided to build a solid foundation (Deck/) and build the game (BlackJack/) as an implementation of the foundation.
As such, I built Deck to be a functional foundation for any command-line-based game. Deck holds an array of Card objects, which contain a Suite (an enum) and a value (number). I use an array for the Card object, because Javascript supports stack operations by default (peek and pop). The runtime also remains practically constant.
The actual game itself is broken up into 3 classes - BlackJack, Interface, and Player (leveraging an enum, Decision).
I wrote the core game class, BlackJack by taking the logic from last year's submission and heavily modularizing the components. By doing so, I cleaned up the code, made it more efficient, and fixed several bugs.
The UserInterface class was written to keep ui printing away from the main game. If this game was to be ported to a different medium, the existing Interface would easily be able to become true to its name and be used as an interface for that different medium.
In UserInterface, a method exists called promptData(). This function prompts the user for any custom data type and will not quit until it passes the user-specified verification method. This method is extremely powerful and is used to write the other prompt methods and is also why the Decision enum exists.
In BlackJack, we prompt the user for a decision, which utilizing promptData(), we're able to get a guranteed exhaustive case checking to help with the backend logic.
Lastly, the Player class manages the balance, bid, and cards for the user and the dealer. To implement splitting, I followed my advice from last year (in that writeup I wrote about what I would change to make splitting work) and have an instance variable called hands in the Player class, which contains every possible hand for the Player.
Some UI Notes
I purposely made sure almost every action within the actual game takes as little keystrokes as possible. Every decision can be made by a single key press (no enter needed!) with the only exception of entering the users bid.
I also ask the user about clearing - the best experience is yes, but I provided the alternative in case the user wanted an easy way to see their progress (users who opt to clear can simply scroll to see their history).
Tests
I confess that testing is where I need to improve the most. My testing experience froms primarily from the basic unit testing I did in my past two internships I did (chai @ Zesty, JUnit @ US Digital Service). I wasn't entirely sure how to properly implement tests for the BlackJack class, but I wrote simple tests for Deck, Card, and Player using Chai and Mocha — and fixed some bugs, most notably Javascript's use of lexicographic sorting (when I had assumed numeric).
Since I'm not great at testing, I'm taking CSE 110 - Software Engineering this year to make sure I get an academic setting to learn tests. Additionally, through my work with ACM at UC San Diego, we're making sure to be doing test-driven development.
To run the tests I've included, simply run
npm test
Last year, I submitted blackjack as my coding sample. However, because I heard about KP too late, I didn't have to make the best sample that truly represented my abilities. This time, I did have the time. I reused some of the original code, but instead rewrote the entire project in Typescript, a language my mentor and boss had told me about while working at the US Digital Service. This project provided to be an amazing way to learn about Typescript's features, and I now feel confident listing Typescript as a skill.