make db interface async (#86)

* persist game state inside db

* undo some unnecessary changes

* fix merge

* fix tests

* no babel on src/server

* reset package-lock.json

* remove stage-0 preset

Author: saeidalidadi

.babelrc

@@ -2,7 +2,6 @@
   "presets": [
     ["es2015", { "modules": false }],
     "react",
-    "stage-0"
   ],
   "env": {
     "targets": {
@@ -21,5 +20,7 @@
         "boardgame.io": "./packages",
       }
     }],
+    "transform-object-rest-spread",
+    "transform-class-properties"
   ]
 }

package.json

@@ -62,10 +62,11 @@
     "babel-loader": "^7.1.2",
     "babel-plugin-external-helpers": "^6.22.0",
     "babel-plugin-module-resolver": "^3.0.0",
+    "babel-plugin-transform-class-properties": "^6.24.1",
     "babel-plugin-transform-es2015-modules-commonjs": "^6.26.0",
+    "babel-plugin-transform-object-rest-spread": "^6.26.0",
     "babel-preset-es2015": "^6.24.1",
     "babel-preset-react": "^6.24.1",
-    "babel-preset-stage-0": "^6.24.1",
     "babel-watch": "^2.0.7",
     "chess.js": "^0.10.2",
     "coveralls": "^3.0.0",

rollup.npm.js

@@ -41,7 +41,7 @@ export default [
     output: { file: 'dist/server.js', format: 'cjs' },
     name: 'Server',
     plugins: [
-      babel({ exclude: '**/node_modules/**' }),
+      babel({ exclude: ['**/node_modules/**'] }),
       commonjs({
         exclude: 'node_modules/**',
       }),

src/server/db.js

@@ -20,28 +20,27 @@ export class InMemory {
   /**
    * Write the game state to the in-memory object.
    * @param {string} id - The game id.
-   * @param {object} store - A Redux store to persist.
+   * @param {object} store - A game state to persist.
    */
-  set(id, store) {
-    this.games.set(id, store);
+  async set(id, state) {
+    return await this.games.set(id, state);
   }
 
   /**
    * Read the game state from the in-memory object.
    * @param {string} id - The game id.
-   * @returns {object} - A Redux store with the game state, or undefined
+   * @returns {object} - A game state, or undefined
    *                     if no game is found with this id.
    */
-  get(id) {
-    return this.games.get(id);
+  async get(id) {
+    return await this.games.get(id);
   }
-
   /**
    * Read the game state from the in-memory object.
    * @param {string} id - The game id.
    * @returns {boolean} - True if a game with this id exists.
    */
-  has(id) {
-    return this.games.has(id);
+  async has(id) {
+    return await this.games.has(id);
   }
 }

src/server/db.test.js

@@ -9,18 +9,22 @@
 import { InMemory } from './db';
 import * as Redux from 'redux';
 
-test('basic', () => {
+test('basic', async () => {
   const db = new InMemory();
   const reducer = () => {};
   const store = Redux.createStore(reducer);
 
   // Must return undefined when no game exists.
-  expect(db.get('gameID')).toEqual(undefined);
+  let state = await db.get('gameID');
+  expect(state).toEqual(undefined);
+
   // Create game.
-  db.set('gameID', store);
+  await db.set('gameID', store.getState());
   // Must return created game.
-  expect(db.get('gameID')).toEqual(store);
+  state = await db.get('gameID');
+  expect(state).toEqual(store.getState());
 
   // Must return true if game exists
-  expect(db.has('gameID')).toEqual(true);
+  let has = await db.has('gameID');
+  expect(has).toEqual(true);
 });

src/server/index.js

@@ -29,14 +29,18 @@ function Server({ games, db }) {
     const nsp = app._io.of(game.name);
 
     nsp.on('connection', socket => {
-      socket.on('action', (action, stateID, gameID, playerID) => {
-        const store = db.get(gameID);
+      socket.on('action', async (action, stateID, gameID, playerID) => {
+        let state = await db.get(gameID);
 
-        if (store === undefined) {
+        if (state === undefined) {
           return { error: 'game not found' };
         }
 
-        const state = store.getState();
+        const reducer = createGameReducer({
+          game,
+          numPlayers: state.ctx.numPlayers,
+        });
+        const store = Redux.createStore(reducer, state);
 
         // The null player is a view-only player.
         if (playerID == null) {
@@ -55,33 +59,30 @@ function Server({ games, db }) {
         if (state._id == stateID) {
           // Update server's version of the store.
           store.dispatch(action);
-          const state = store.getState();
+          state = store.getState();
 
           // Get clients connected to this current game.
           const roomClients = roomInfo.get(gameID);
           for (const client of roomClients.values()) {
             const playerID = clientInfo.get(client).playerID;
+            const newState = Object.assign({}, state, {
+              G: game.playerView(state.G, state.ctx, playerID),
+            });
 
             if (client === socket.id) {
-              socket.emit('sync', gameID, {
-                ...state,
-                G: game.playerView(state.G, state.ctx, playerID),
-              });
+              socket.emit('sync', gameID, newState);
             } else {
-              socket.to(client).emit('sync', gameID, {
-                ...state,
-                G: game.playerView(state.G, state.ctx, playerID),
-              });
+              socket.to(client).emit('sync', gameID, newState);
             }
           }
 
-          db.set(gameID, store);
+          db.set(gameID, store.getState());
         }
       });
 
-      socket.on('sync', (gameID, playerID, numPlayers) => {
+      socket.on('sync', async (gameID, playerID, numPlayers) => {
         socket.join(gameID);
-
+        const reducer = createGameReducer({ game, numPlayers });
         let roomClients = roomInfo.get(gameID);
         if (roomClients === undefined) {
           roomClients = new Set();
@@ -91,18 +92,20 @@ function Server({ games, db }) {
 
         clientInfo.set(socket.id, { gameID, playerID });
 
-        let store = db.get(gameID);
-        if (store === undefined) {
-          const reducer = createGameReducer({ game, numPlayers });
-          store = Redux.createStore(reducer);
-          db.set(gameID, store);
+        let state = await db.get(gameID);
+        if (state === undefined) {
+          const store = Redux.createStore(reducer);
+          state = store.getState();
+          await db.set(gameID, state);
         }
 
-        const state = store.getState();
-        socket.emit('sync', gameID, {
-          ...state,
+        const newState = Object.assign({}, state, {
           G: game.playerView(state.G, state.ctx, playerID),
         });
+
+        socket.emit('sync', gameID, newState);
+
+        return;
       });
 
       socket.on('disconnect', () => {

src/server/index.test.js

@@ -20,8 +20,9 @@ jest.mock('koa-socket', () => {
       this.broadcast = { emit: jest.fn() };
     }
 
-    receive(type, ...args) {
-      this.callbacks[type](args[0], args[1], args[2], args[3], args[4]);
+    async receive(type, ...args) {
+      await this.callbacks[type](args[0], args[1], args[2], args[3], args[4]);
+      return;
     }
 
     on(type, callback) {
@@ -65,7 +66,7 @@ test('basic', () => {
   io.socket.receive('disconnect');
 });
 
-test('sync', () => {
+test('sync', async () => {
   const server = Server({ games: [game] });
   const io = server.context.io;
   expect(server).not.toBe(undefined);
@@ -74,40 +75,42 @@ test('sync', () => {
 
   // Sync causes the server to respond.
   expect(io.socket.emit).toHaveBeenCalledTimes(0);
-  io.socket.receive('sync', 'gameID');
+  await io.socket.receive('sync', 'gameID');
+
   expect(io.socket.emit).toHaveBeenCalledTimes(1);
   expect(spy).toHaveBeenCalled();
 
   // Sync a second time does not create a game.
   spy.mockReset();
-  io.socket.receive('sync', 'gameID');
+  await io.socket.receive('sync', 'gameID');
+
   expect(io.socket.emit).toHaveBeenCalledTimes(2);
   expect(spy).not.toHaveBeenCalled();
 
   spy.mockRestore();
 });
 
-test('action', () => {
+test('action', async () => {
   const server = Server({ games: [game] });
   const io = server.context.io;
   const action = ActionCreators.gameEvent('endTurn');
 
-  io.socket.receive('action', action);
+  await io.socket.receive('action', action);
   expect(io.socket.emit).toHaveBeenCalledTimes(0);
   io.socket.emit.mockReset();
 
-  io.socket.receive('sync', 'gameID');
+  await io.socket.receive('sync', 'gameID');
   io.socket.id = 'second';
-  io.socket.receive('sync', 'gameID');
+  await io.socket.receive('sync', 'gameID');
   io.socket.emit.mockReset();
 
   // View-only players cannot send actions.
-  io.socket.receive('action', action, 0, 'gameID', null);
+  await io.socket.receive('action', action, 0, 'gameID', null);
   expect(io.socket.emit).not.toHaveBeenCalled();
 
   // Actions are broadcasted as state updates.
   // The playerID parameter is necessary to account for view-only players.
-  io.socket.receive('action', action, 0, 'gameID', '0');
+  await io.socket.receive('action', action, 0, 'gameID', '0');
   expect(io.socket.emit).lastCalledWith('sync', 'gameID', {
     G: {},
     _id: 1,
@@ -141,55 +144,55 @@ test('action', () => {
   io.socket.emit.mockReset();
 
   // ... but not if the gameID is not known.
-  io.socket.receive('action', action, 1, 'unknown', '1');
+  await io.socket.receive('action', action, 1, 'unknown', '1');
   expect(io.socket.emit).toHaveBeenCalledTimes(0);
 
   // ... and not if the _id doesn't match the internal state.
-  io.socket.receive('action', action, 100, 'gameID', '1');
+  await io.socket.receive('action', action, 100, 'gameID', '1');
   expect(io.socket.emit).toHaveBeenCalledTimes(0);
 
   // ... and not if player != currentPlayer
-  io.socket.receive('action', action, 1, 'gameID', '100');
+  await io.socket.receive('action', action, 1, 'gameID', '100');
   expect(io.socket.emit).toHaveBeenCalledTimes(0);
 
   // Another broadcasted action.
-  io.socket.receive('action', action, 1, 'gameID', '1');
+  await io.socket.receive('action', action, 1, 'gameID', '1');
   expect(io.socket.emit).toHaveBeenCalledTimes(2);
 });
 
-test('playerView (sync)', () => {
+test('playerView (sync)', async () => {
   // Write the player into G.
   const game = Game({
     playerView: (G, ctx, player) => {
-      return { ...G, player };
+      return Object.assign({}, G, { player });
     },
   });
 
   const server = Server({ games: [game] });
   const io = server.context.io;
 
-  io.socket.receive('sync', 'gameID', 0);
+  await io.socket.receive('sync', 'gameID', 0);
   expect(io.socket.emit).toHaveBeenCalledTimes(1);
   expect(io.socket.emit.mock.calls[0][2].G).toEqual({ player: 0 });
 });
 
-test('playerView (action)', () => {
+test('playerView (action)', async () => {
   const game = Game({
     playerView: (G, ctx, player) => {
-      return { ...G, player };
+      return Object.assign({}, G, { player });
     },
   });
   const server = Server({ games: [game] });
   const io = server.context.io;
   const action = ActionCreators.gameEvent('endTurn');
 
   io.socket.id = 'first';
-  io.socket.receive('sync', 'gameID', '0', 2);
+  await io.socket.receive('sync', 'gameID', '0', 2);
   io.socket.id = 'second';
-  io.socket.receive('sync', 'gameID', '1', 2);
+  await io.socket.receive('sync', 'gameID', '1', 2);
   io.socket.emit.mockReset();
 
-  io.socket.receive('action', action, 0, 'gameID', '0');
+  await io.socket.receive('action', action, 0, 'gameID', '0');
   expect(io.socket.emit).toHaveBeenCalledTimes(2);
 
   const G_player0 = io.socket.emit.mock.calls[0][2].G;
@@ -199,19 +202,26 @@ test('playerView (action)', () => {
   expect(G_player1.player).toBe('1');
 });
 
-test('custom db implementation', () => {
+test('custom db implementation', async () => {
   let getId = null;
+
   class Custom {
-    get(id) {
+    constructor() {
+      this.games = new Map();
+    }
+    async get(id) {
       getId = id;
+      return await this.games.get(id);
+    }
+    async set(id, state) {
+      return await this.games.set(id, state);
     }
-    set() {}
   }
 
   const game = Game({});
   const server = Server({ games: [game], db: new Custom() });
   const io = server.context.io;
 
-  io.socket.receive('sync', 'gameID');
+  await io.socket.receive('sync', 'gameID');
   expect(getId).toBe('gameID');
 });