Skip to content

dojonorth/poker-hands-kata-js

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 

History

1 Commit
 
 
 
 
 
 
 
 

Repository files navigation

Poker Hands Kata

How to Run Tests

Run All Tests

npm test

Watching Tests

npm install -g mocha
mocha -w

Objectives

The focus is to practice writing the best code we can possibly write and challenge ourselves.

Rules

  • Developers will work in pairs; preferably with a person that they never paired before.
  • As a rule, TDD is mandatory.
  • Facilitator should run a small retrospective at the end, where all developers can share what they've done, how they've done it, and what they've learnt.
  • Developers thank their pairs when the session is over.

What is not a kata/coding dojo?

  • It's not a master class nor a workshop.
  • It's not a place to learn new languages.
  • It's not a place to learn how to set up an environment.

PokerHands

Before you start:

  • Do one task at a time. The trick is to learn to work incrementally.

PokerHands

Your job is to compare several pairs of poker hands and to indicate which, if either, has a higher rank.

Rules description

A poker deck contains 52 cards - each card has a suit which is one of clubs, diamonds, hearts, or spades (denoted C, D, H, and S in the input data). Each card also has a value which is one of 2, 3, 4, 5, 6, 7, 8, 9, 10, jack, queen, king, ace (denoted 2, 3, 4, 5, 6, 7, 8, 9, T, J, Q, K, A). For scoring purposes, the suits are unordered while the values are ordered as given above, with 2 being the lowest and ace the highest value.

A poker hand consists of 5 cards dealt from the deck. Poker hands are ranked by the following partial order from lowest to highest.

  • High Card: Hands which do not fit any higher category are ranked by the value of their highest card. If the highest cards have the same value, the hands are ranked by the next highest, and so on.
  • Pair: 2 of the 5 cards in the hand have the same value. Hands which both contain a pair are ranked by the value of the cards forming the pair. If these values are the same, the hands are ranked by the values of the cards not forming the pair, in decreasing order.
  • Two Pairs: The hand contains 2 different pairs. Hands which both contain 2 pairs are ranked by the value of their highest pair. Hands with the same highest pair are ranked by the value of their other pair. If these values are the same the hands are ranked by the value of the remaining card.
  • Three of a Kind: Three of the cards in the hand have the same value. Hands which both contain three of a kind are ranked by the value of the 3 cards.
  • Straight: Hand contains 5 cards with consecutive values. Hands which both contain a straight are ranked by their highest card.
  • Flush: Hand contains 5 cards of the same suit. Hands which are both flushes are ranked using the rules for High Card.
  • Full House: 3 cards of the same value, with the remaining 2 cards forming a pair. Ranked by the value of the 3 cards.
  • Four of a kind: 4 cards with the same value. Ranked by the value of the 4 cards.
  • Straight flush: 5 cards of the same suit with consecutive values. Ranked by the highest card in the hand.

For Illustrations: http://www.cardplayer.com/rules-of-poker/hand-rankings

Test cases

Sample input:

Black White
2H 3D 5S 9C KD 2C 3H 4S 8C AH
2H 4S 4C 2D 4H 2S 8S AS QS 3S
2H 3D 5S 9C KD 2C 3H 4S 8C KH
2H 3D 5S 9C KD 2D 3H 5C 9S KH

Each row of input is a game with two players. The first five cards belong to the player named "Black" and the second five cards belong to the player named "White".

Sample output:

White wins. - with high card: Ace
White wins. - with flush
Black wins. - with high card: 9
Tie.

Web: http://codingdojo.org/cgi-bin/index.pl?KataPokerHands

Additional Suggestions
  • Start small - create the Card, the Hand/Rules, then onto the Game objects to compare two hands
  • Ignore comparing equal hand types to begin with (e.g comparing two straight hands) - this can be done as an additional exercise once the basic structure is in place

Releases

No releases published

Packages

No packages published