Server-side array shuffling. (#116)

* deterministic array shuffling

* use fast-shuffle for faster shuffle

* fix rollup config

Author: philihp

docs/random.md

@@ -50,6 +50,29 @@ const SomeGame = Game({
 This will place a request to a D6 dice roll inside `G`.
 While processing the move, the request gets evaluated and the result placed into `diceValue`, where it can be used.
 
+### Shuffles
+
+To simulate a shuffled deck of cards, sometimes it might be simplest to draw a card from a random index in an array. This can get confusing if your game moves
+include a move for peeking at the top card which is later rendered moot by
+another move which shuffles the deck. To simplify modeling this, you might want
+to represent your deck as an array. Use `Random.Shuffle` to perform a shallow
+shuffle of the elements.
+
+```js
+import { Random } from 'boardgame.io/core';
+
+const SomeGame = Game({
+  setup: () => ({
+    deck: ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'],
+  }),
+  moves: {
+    shuffleDeck(G) {
+      return Random.Shuffle(G, 'deck');
+    },
+  },
+});
+```
+
 ## Seed
 
 The library uses a `seed` in `ctx` that is stripped before it

docs/react/boardgameio.min.js

@@ -10,6 +10,7 @@ import tic_tac_toe from './tic-tac-toe';
 import chess from './chess';
 import phases from './phases';
 import liars_dice from './liars-dice';
+import shuffle from './shuffle';
 
 const routes = [
   {
@@ -28,6 +29,10 @@ const routes = [
     name: 'Liars Dice',
     routes: liars_dice.routes,
   },
+  {
+    name: 'Shuffle',
+    routes: shuffle.routes,
+  },
 ];
 
 export default routes;

examples/modules/routes.js

@@ -0,0 +1,18 @@
+/*
+ * Copyright 2018 The boardgame.io Authors.
+ *
+ * Use of this source code is governed by a MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT.
+ */
+
+import React from 'react';
+import PropTypes from 'prop-types';
+
+const Board = ({ G }) => <pre>{JSON.stringify(G, null, 2)}</pre>;
+
+Board.propTypes = {
+  G: PropTypes.any.isRequired,
+};
+
+export default Board;

examples/modules/shuffle/components/board.js

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2018 The boardgame.io Authors.
+ *
+ * Use of this source code is governed by a MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT.
+ */
+
+import React from 'react';
+import { Client } from 'boardgame.io/client';
+import Game from '../game';
+import Board from './board';
+
+const App = Client({
+  game: Game,
+  numPlayers: 1,
+  board: Board,
+});
+
+const SingleView = () => (
+  <div style={{ padding: 50 }}>
+    <App gameID="Shuffle" />
+  </div>
+);
+
+export default SingleView;

examples/modules/shuffle/components/view.js

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2018 The boardgame.io Authors
+ *
+ * Use of this source code is governed by a MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT.
+ */
+
+import { Game, Random } from 'boardgame.io/core';
+
+const Shuffle = Game({
+  name: 'shuffle',
+
+  setup: () => ({
+    deck: ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'],
+  }),
+
+  moves: {
+    shuffle: G => Random.Shuffle(G, 'deck'),
+  },
+});
+
+export default Shuffle;

examples/modules/shuffle/game.js

@@ -0,0 +1,14 @@
+/*
+ * Copyright 2018 The boardgame.io Authors.
+ *
+ * Use of this source code is governed by a MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT.
+ */
+
+import routes from './routes';
+
+// Any other additional setup for this this module
+export default {
+  routes,
+};

examples/modules/shuffle/index.js

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2018 The boardgame.io Authors.
+ *
+ * Use of this source code is governed by a MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT.
+ */
+
+import View from './components/view';
+
+const routes = [
+  {
+    path: '/shuffle/cards',
+    text: 'Shuffle Cards',
+    component: View,
+  },
+];
+
+export default routes;

examples/modules/shuffle/routes.js

@@ -109,6 +109,7 @@
     "webpack": "^3.5.5"
   },
   "dependencies": {
+    "fast-shuffle": "^1.0.4",
     "koa": "^2.3.0",
     "koa-router": "^7.2.1",
     "koa-socket": "^4.4.0",