split plugin.setup into setupG and setupCtx

docs/plugins.md

@@ -25,10 +25,12 @@ A plugin is an object that contains the following fields.
   },
 
   // Optional.
-  // Called during setup. The return value is merged
-  // with the initial value of G. This is typically
-  // used to store state that is managed by this
-  setup: ctx => state,
+  // Called during setup in order to add state to G.
+  setupG: (G, ctx) => G,
+
+  // Optional.
+  // Called during setup in order to add state to ctx.
+  setupCtx: (ctx) => ctx,
 }
 ```
 

src/core/plugins/main.test.js

@@ -12,20 +12,39 @@ import { makeMove } from '../action-creators';
 
 describe('plugins', () => {
   let game;
+  let reducer;
+
   beforeAll(() => {
     game = Game({
       moves: {
         A: G => G,
       },
 
-      plugins: [{ fnWrap: () => () => ({ plugin: true }) }],
+      plugins: [
+        {
+          fnWrap: () => G => ({ ...G, fnWrap: true }),
+          setupG: G => ({ ...G, initG: true }),
+          setupCtx: ctx => ({ ...ctx, initCtx: true }),
+        },
+      ],
     });
+
+    reducer = CreateGameReducer({ game });
+  });
+
+  test('setupG', () => {
+    const state = reducer(undefined, { type: 'init' });
+    expect(state.G).toMatchObject({ initG: true });
+  });
+
+  test('setupCtx', () => {
+    const state = reducer(undefined, { type: 'init' });
+    expect(state.ctx).toMatchObject({ initCtx: true });
   });
 
-  test('plugin is invoked', () => {
-    const reducer = CreateGameReducer({ game });
+  test('fnWrap', () => {
     let state = reducer(undefined, { type: 'init' });
     state = reducer(state, makeMove('A'));
-    expect(state.G).toEqual({ plugin: true });
+    expect(state.G).toMatchObject({ fnWrap: true });
   });
 });

src/core/plugins/plugin-player.js

@@ -48,7 +48,7 @@ export default initPlayerState => ({
     };
   },
 
-  setup: (G, ctx) => {
+  setupG: (G, ctx) => {
     let players = {};
     for (let i = 0; i < ctx.numPlayers; i++) {
       const playerState = {};

src/core/plugins/plugin-player.test.js

@@ -13,7 +13,7 @@ import { makeMove, gameEvent } from '../action-creators';
 
 describe('default values', () => {
   test('playerState is not passed', () => {
-    const value = PluginPlayer().setup({}, { numPlayers: 2 });
+    const value = PluginPlayer().setupG({}, { numPlayers: 2 });
     expect(value).toEqual({ players: { '0': {}, '1': {} } });
   });
 });

src/core/reducer.js

@@ -126,12 +126,21 @@ export function CreateGameReducer({
   }
   ctx._random = { seed };
 
+  // Pass ctx through all the plugins that want to modify it.
+  game.plugins
+    .filter(plugin => plugin.setupCtx !== undefined)
+    .forEach(plugin => {
+      ctx = plugin.setupCtx(ctx);
+    });
+
+  // Augment ctx with the enhancers (TODO: move these into plugins).
   const apiCtx = new ContextEnhancer(ctx, game, ctx.currentPlayer);
   let ctxWithAPI = apiCtx.attachToContext(ctx);
 
+  // Pass G through all the plugins that want to modify it.
   let initialG = game.setup(ctxWithAPI, setupData);
-  game.plugins.filter(plugin => plugin.setup !== undefined).forEach(plugin => {
-    initialG = plugin.setup(initialG, ctxWithAPI);
+  game.plugins.filter(plugin => plugin.setupG !== undefined).forEach(plugin => {
+    initialG = plugin.setupG(initialG, ctxWithAPI);
   });
 
   const initial = {