Flow-type example for Tennis Kata

tennisKata.js

/* @flow */

type Point = 'Love' | 'Fifteen' | 'Thirty';
type Deuce = 'Deuce';

type PlayerOne = 'Player1';
type PlayerTwo = 'Player2';
type Player = PlayerOne | PlayerTwo;
type GameOfPlayer = {
  gameOfPlayer: Player
}

// A status that one of players reaches 'Forty'(before first deuce) first
type FortyData = {
  Player : Player,
  OtherPlayerPoint : Point,
}

type Advantage = {
  advantage : Player,
}

// Both players haven't reaching deuce
type PointsData = { PlayerOnePoint : Point; PlayerTwoPoint : Point };

type Score = PointsData | FortyData | Deuce | Advantage | GameOfPlayer;

let start: Score = {
  PlayerOnePoint: 'Love',
  PlayerTwoPoint: 'Love',
};

let ball1: Score = {
  PlayerOnePoint: 'Fifteen',
  PlayerTwoPoint: 'Love',
};

let ball2: Score = {
  PlayerOnePoint: 'Thirty',
  PlayerTwoPoint: 'Love',
};

let ball3: Score = {
  PlayerOnePoint: 'Thirty',
  PlayerTwoPoint: 'Thirty',
};

let ball4: Score = {
  Player: 'Player1',
  OtherPlayerPoint: 'Thirty',
};

let ball5: Score = 'Deuce';

let ball6: Score = {
  advantage: 'Player1'
};

let ball7: Score = {
  gameOfPlayer: 'Player1'
};

http://blog.ploeh.dk/2016/02/10/types-properties-software-designing-with-types/