initial implementation of subscriptions

helfer · helfer · commit 6f4849fb69e3 · 2016-09-12T11:50:31.000-07:00
diff --git a/api/index.js b/api/index.js
@@ -13,13 +13,19 @@ import { GitHubConnector } from './github/connector';
 import { Repositories, Users } from './github/models';
 import { Entries, Comments } from './sql/models';
 
+import { createServer } from 'http';
+import { Server } from 'subscriptions-transport-ws';
+import { subscriptionManager } from './subscriptions';
+
 import schema from './schema';
 
 let PORT = 3010;
 if (process.env.PORT) {
   PORT = parseInt(process.env.PORT, 10) + 100;
 }
 
+const WS_PORT = process.env.WS_PORT || 8080;
+
 const app = express();
 
 app.use(bodyParser.urlencoded({ extended: true }));
@@ -91,3 +97,35 @@ app.get('/', (req, res) => {
 app.listen(PORT, () => console.log( // eslint-disable-line no-console
   `API Server is now running on http://localhost:${PORT}`
 ));
+
+// WebSocket server for subscriptions
+const httpServer = createServer((request, response) => {
+  response.writeHead(404);
+  response.end();
+});
+
+httpServer.listen(WS_PORT, () => console.log( // eslint-disable-line no-console
+  `Websocket Server is now running on http://localhost:${WS_PORT}`
+));
+
+// eslint-disable-next-line
+new Server(
+  {
+    subscriptionManager,
+    onSubscribe: (msg, params) => {
+      const gitHubConnector = new GitHubConnector({
+        clientId: GITHUB_CLIENT_ID,
+        clientSecret: GITHUB_CLIENT_SECRET,
+      });
+      return Object.assign({}, params, {
+        context: {
+          Repositories: new Repositories({ connector: gitHubConnector }),
+          Users: new Users({ connector: gitHubConnector }),
+          Entries: new Entries(),
+          Comments: new Comments(),
+        },
+      });
+    },
+  },
+  httpServer
+);
diff --git a/api/schema.js b/api/schema.js
@@ -2,6 +2,7 @@ import { merge } from 'lodash';
 import { schema as gitHubSchema, resolvers as gitHubResolvers } from './github/schema';
 import { schema as sqlSchema, resolvers as sqlResolvers } from './sql/schema';
 import { makeExecutableSchema } from 'graphql-tools';
+import { pubsub } from './subscriptions';
 
 const rootSchema = [`
 
@@ -73,9 +74,15 @@ type Mutation {
   ): Comment
 }
 
+type Subscription {
+  # Subscription fires on every comment added
+  commentAdded(repoFullName: String!): Comment
+}
+
 schema {
   query: Query
   mutation: Mutation
+  subscription: Subscription
 }
 
 `];
@@ -126,9 +133,14 @@ const rootResolvers = {
             commentContent
           )
         ))
-        .then(([id]) => (
+        .then(([id]) =>
           context.Comments.getCommentById(id)
-        ));
+        )
+        .then(comment => {
+          // publish subscription notification
+          pubsub.publish('commentAdded', comment);
+          return comment;
+        });
     },
 
     vote(root, { repoFullName, type }, context) {
@@ -151,6 +163,12 @@ const rootResolvers = {
       ));
     },
   },
+  Subscription: {
+    commentAdded(comment) {
+      // the subscription payload is the comment.
+      return comment;
+    },
+  },
 };
 
 // Put schema together into one array of schema strings
diff --git a/api/sql/schema.js b/api/sql/schema.js
@@ -4,6 +4,9 @@ export const schema = [`
 
 # A comment about an entry, submitted by a user
 type Comment {
+  # The SQL ID of this entry
+  id: Int!
+
   # The GitHub user who posted the comment
   postedBy: User!
 
diff --git a/api/subscriptions.js b/api/subscriptions.js
@@ -0,0 +1,17 @@
+import { PubSub, SubscriptionManager } from 'graphql-subscriptions';
+import schema from './schema';
+
+const pubsub = new PubSub();
+const subscriptionManager = new SubscriptionManager({
+  schema,
+  pubsub,
+  setupFunctions: {
+    commentAdded: (options, args) => ({
+      commentAdded: comment => {
+        return comment.repository_name === args.repoFullName;
+      },
+    }),
+  },
+});
+
+export { subscriptionManager, pubsub };
diff --git a/package.json b/package.json
@@ -48,12 +48,14 @@
     "express": "^4.13.4",
     "express-session": "^1.13.0",
     "graphql": "^0.7.0",
+    "graphql-subscriptions": "^0.1.0",
     "graphql-tools": "^0.6.2",
     "knex": "^0.11.3",
     "lodash": "^4.12.0",
     "passport": "^0.3.2",
     "passport-github": "^1.1.0",
     "request-promise": "^3.0.0",
-    "sqlite3": "^3.1.4"
+    "sqlite3": "^3.1.4",
+    "subscriptions-transport-ws": "^0.1.2"
   }
 }
