Make Random package not depend on global state (#146)

* remove global state

* update docs

* remove from package

* update docs

* update docs

* review comments

* update docs/react/boardgameio.min.js

docs/api/Game.md

@@ -52,7 +52,7 @@ game state and the moves. The moves are converted to a
 import { Game } from `boardgame.io/core';
 
 const game = Game({
-  setup: (numPlayers) => {
+  setup: (ctx) => {
     const G = {...};
     return G;
   },
@@ -75,7 +75,7 @@ const game = Game({
 import { Game } from 'boardgame.io/core';
 
 const game = Game({
-  setup: (numPlayers) => {
+  setup: (ctx) => {
     ...
   },
 
@@ -99,7 +99,7 @@ const game = Game({
 import { Game } from 'boardgame.io/core';
 
 const game = Game({
-  setup: (numPlayers) => {
+  setup: (ctx) => {
     ...
   },
 

docs/api/Random.md

@@ -2,7 +2,7 @@
 
 API for code that requires randomness. See the guide [here](random.md).
 
-## 1. Random.Die
+## 1. Die
 
 ### Arguments
 
@@ -16,32 +16,28 @@ The die roll value (or an array of values if `diceCount` is greater than `1`).
 #### Usage
 
 ```js
-import { Random } from `boardgame.io/core';
-
 const game = Game({
   moves: {
     move(G, ctx) {
-      const die = Random.Die(6);      // die = 1-6
-      const dice = Random.Die(6, 3);  // dice = [1-6, 1-6, 1-6]
+      const die = ctx.random.Die(6);      // die = 1-6
+      const dice = ctx.random.Die(6, 3);  // dice = [1-6, 1-6, 1-6]
       ...
     },
   }
 });
 ```
 
-## 2. Random.Number
+## 2. Number
 
 Returns a random number between `0` and `1`.
 
 #### Usage
 
 ```js
-import { Random } from `boardgame.io/core';
-
 const game = Game({
   moves: {
     move(G, ctx) {
-      const n = Random.Number();
+      const n = ctx.random.Number();
       ...
     },
   }
@@ -61,15 +57,13 @@ The shuffled array.
 #### Usage
 
 ```js
-import { Random } from `boardgame.io/core';
-
 const game = Game({
   moves: {
     move(G, ctx) {
-      const deck = Random.Shuffle(G.deck);
+      const deck = ctx.random.Shuffle(G.deck);
       return { ...G, deck };
     },
-  }
+  },
 });
 ```
 
@@ -85,12 +79,10 @@ const game = Game({
 ### Usage
 
 ```js
-import { Random } from `boardgame.io/core';
-
 const game = Game({
   moves: {
     move(G, ctx) {
-      const die = Random.D6();
+      const die = ctx.random.D6();
       ...
     },
   }

docs/random.md

@@ -22,12 +22,10 @@ This poses interesting challenges regarding the implementation.
 ### Using Randomness in Games
 
 ```js
-import { Random } from 'boardgame.io/core';
-
 Game({
   moves: {
     rollDie(G, ctx) {
-      return { ...G, dice: Random.D6() };
+      return { ...G, dice: ctx.random.D6() };
     },
   },
 });

docs/tutorial.md

@@ -21,9 +21,9 @@ $ npm install --save boardgame.io
 We create the game by providing the initial value of the
 game state `G` (through the `setup` function), and the moves
 of the game. The `setup` function also accepts a
-`numPlayers` parameter if you need to customize the initial
-state based on the number of players, but we don't need that
-for Tic-Tac-Toe.
+`ctx` parameter if you need to customize the initial
+state based on some field in `ctx` (the number of players, for example),
+but we don't need that for Tic-Tac-Toe.
 
 In Tic-Tac-Toe, we have just one type of move that we shall
 name `clickCell`. The move function accepts

examples/modules/random/game.js

@@ -6,7 +6,7 @@
  * https://opensource.org/licenses/MIT.
  */
 
-import { Game, Random } from 'boardgame.io/core';
+import { Game } from 'boardgame.io/core';
 
 const RandomExample = Game({
   name: 'shuffle',
@@ -16,9 +16,9 @@ const RandomExample = Game({
   }),
 
   moves: {
-    shuffle: G => ({ ...G, deck: Random.Shuffle(G.deck) }),
-    rollDie: (G, ctx, value) => ({ ...G, dice: Random.Die(value) }),
-    rollD6: G => ({ ...G, dice: Random.D6() }),
+    shuffle: (G, ctx) => ({ ...G, deck: ctx.random.Shuffle(G.deck) }),
+    rollDie: (G, ctx, value) => ({ ...G, dice: ctx.random.Die(value) }),
+    rollD6: (G, ctx) => ({ ...G, dice: ctx.random.D6() }),
   },
 });
 

packages/core.js

@@ -10,6 +10,5 @@ import Game from '../src/core/game.js';
 import { Flow, FlowWithPhases } from '../src/core/flow.js';
 import { TurnOrder, Pass } from '../src/core/turn-order.js';
 import { PlayerView } from '../src/core/player-view.js';
-import { Random } from '../src/core/random';
 
-export { Game, Flow, FlowWithPhases, TurnOrder, Pass, PlayerView, Random };
+export { Game, Flow, FlowWithPhases, TurnOrder, Pass, PlayerView };

packages/main.js

@@ -15,7 +15,6 @@ import Token from '../src/ui/token.js';
 import { Card } from '../src/ui/card.js';
 import { Grid } from '../src/ui/grid.js';
 import { HexGrid } from '../src/ui/hex.js';
-import { Random } from '../src/core/random';
 
 export default {
   Client,
@@ -29,5 +28,4 @@ export default {
   Token,
   Grid,
   HexGrid,
-  Random,
 };

src/core/flow.js

@@ -7,6 +7,7 @@
  */
 
 import { TurnOrder } from './turn-order';
+import { Random } from './random';
 
 /**
  * Helper to create a reducer that manages ctx (with the
@@ -276,8 +277,9 @@ export function FlowWithPhases({
   };
 
   const startTurn = function(state, config) {
-    const ctx = { ...state.ctx };
+    let ctx = { ...state.ctx };
     const G = config.onTurnBegin(state.G, ctx);
+    ctx = Random.detach(ctx);
     const _undo = [{ G, ctx }];
     return { ...state, G, ctx, _undo, _redo: [] };
   };

src/core/game.js

@@ -7,7 +7,7 @@
  */
 
 import { FlowWithPhases } from './flow';
-import { GenSeed } from './random';
+import { Random } from './random';
 
 /**
  * Game
@@ -76,7 +76,7 @@ function Game({ name, setup, moves, playerView, flow, seed }) {
   if (setup === undefined) setup = () => ({});
   if (moves === undefined) moves = {};
   if (playerView === undefined) playerView = G => G;
-  if (seed === undefined) seed = GenSeed();
+  if (seed === undefined) seed = Random.seed();
 
   if (!flow || flow.processGameEvent === undefined) {
     flow = FlowWithPhases(flow || {});