add subscriptions for /northwind schema

Author: nodkz

examples/northwind/schema.js

@@ -20,6 +20,9 @@ import { SupplierTC } from './models/supplier';
 import { addQueryToPayload } from './wrappers/addQueryToPayload';
 import { autoResetDataIn30min } from './wrappers/autoResetDataIn30min';
 import { seedByName } from '../../scripts/seedHelpers';
+import { PubSub } from 'apollo-server-express';
+
+const pubsub = new PubSub();
 
 const ViewerTC = schemaComposer.getOrCreateOTC('Viewer');
 schemaComposer.Query.addFields({
@@ -71,9 +74,27 @@ schemaComposer.Mutation.addFields({
       updateProduct: ProductTC.getResolver('updateById'),
       removeProduct: ProductTC.getResolver('removeOne'),
 
-      createOrder: OrderTC.getResolver('createOne'),
-      updateOrder: OrderTC.getResolver('updateById'),
-      removeOrder: OrderTC.getResolver('removeOne'),
+      createOrder: OrderTC.getResolver('createOne', [
+        async (next, s, a, c, i) => {
+          const res = await next(s, a, c, i);
+          pubsub.publish('ORDER_CREATED', res.record);
+          return res;
+        },
+      ]),
+      updateOrder: OrderTC.getResolver('updateById', [
+        async (next, s, a, c, i) => {
+          const res = await next(s, a, c, i);
+          pubsub.publish('ORDER_UPDATED', res.record);
+          return res;
+        },
+      ]),
+      removeOrder: OrderTC.getResolver('removeOne', [
+        async (next, s, a, c, i) => {
+          const res = await next(s, a, c, i);
+          pubsub.publish('ORDER_REMOVED', res.record);
+          return res;
+        },
+      ]),
 
       updateEmployee: EmployeeTC.getResolver('updateById'),
     }),
@@ -89,4 +110,27 @@ schemaComposer.Mutation.addFields({
   },
 });
 
+// About subscriptions you can reead here:
+// - https://www.apollographql.com/docs/apollo-server/data/subscriptions/
+// - https://github.com/apollographql/subscriptions-transport-ws
+// - https://github.com/apollographql/apollo-server/blob/master/packages/apollo-server-core/src/ApolloServer.ts
+// - https://github.com/graphql/graphql-js/blob/master/src/subscription/__tests__/subscribe-test.js
+schemaComposer.Subscription.addFields({
+  orderCreated: {
+    type: OrderTC,
+    resolve: (record) => record,
+    subscribe: () => pubsub.asyncIterator(['ORDER_CREATED']),
+  },
+  orderUpdated: {
+    type: OrderTC,
+    resolve: (record) => record,
+    subscribe: () => pubsub.asyncIterator(['ORDER_UPDATED']),
+  },
+  orderRemoved: {
+    type: 'MongoID',
+    resolve: (record) => record,
+    subscribe: () => pubsub.asyncIterator(['ORDER_REMOVED']),
+  },
+});
+
 export default schemaComposer.buildSchema();

index.js

@@ -1,16 +1,21 @@
+/* eslint-disable no-new */
 /* @flow */
 
 import express from 'express';
 import cors from 'cors';
-import graphqlHTTP from 'express-graphql';
-import expressPlayground from 'graphql-playground-middleware-express';
+import { ApolloServer } from 'apollo-server-express';
 import { altairExpress } from 'altair-express-middleware';
+import { express as voyagerMiddleware } from 'graphql-voyager/middleware';
+import http from 'http';
+import { SubscriptionServer } from 'subscriptions-transport-ws';
+import { execute, subscribe } from 'graphql';
 import { mainPage, addToMainPage } from './mainPage';
 import { expressPort, getExampleNames, resolveExamplePath } from './config';
 import './mongooseConnection';
 
-const server = express();
-server.use(cors({ origin: true, credentials: true }));
+const app = express();
+const httpServer = http.createServer(app);
+app.use(cors({ origin: true, credentials: true }));
 
 // scan `examples` directory and add
 // - graphql endpoint by uri /exampleDirName
@@ -25,28 +30,48 @@ for (const name of exampleNames) {
 }
 
 // $FlowFixMe
-server.get('/', (req, res) => {
+app.get('/', (req, res) => {
   res.send(mainPage());
 });
 
-server.listen(expressPort, () => {
+httpServer.listen(expressPort, () => {
   console.log(`🚀🚀🚀 The server is running at http://localhost:${expressPort}/`);
+
+  // https://www.apollographql.com/docs/graphql-subscriptions/setup/
+  SubscriptionServer.create(
+    {
+      schema: require('./examples/northwind/schema').default,
+      execute,
+      subscribe,
+      onConnect: (connectionParams, ws, context) => {
+        console.log(`WS[connect][${context.request.connection.remoteAddress}]`, connectionParams);
+      },
+      onDisconnect: (ws, context) => {
+        console.log(`WS[disconn][${context.request.connection.remoteAddress}]`);
+      },
+    },
+    {
+      server: httpServer,
+      path: '/northwind',
+    }
+  );
 });
 
 function addExample(example, uri) {
   example.uri = `/${uri}`; // eslint-disable-line
-  server.use(
-    example.uri,
-    (graphqlHTTP(() => ({
-      schema: example.schema,
-      graphiql: true,
-      customFormatErrorFn: (error) => ({
-        message: error.message,
-        stack: !error.message.match(/for security reason/i) ? error.stack.split('\n') : null,
-      }),
-    })): any)
+
+  const server = new ApolloServer({
+    schema: example.schema,
+    playground: {
+      subscriptionEndpoint: example.uri,
+    },
+  });
+  server.applyMiddleware({ app, path: example.uri });
+
+  app.use(
+    `${example.uri}-altair`,
+    altairExpress({ endpointURL: example.uri, subscriptionsEndpoint: example.uri })
   );
-  server.get(`${example.uri}-playground`, expressPlayground({ endpoint: example.uri }));
-  server.use(`${example.uri}-altair`, altairExpress({ endpointURL: example.uri }));
+  app.use(`${example.uri}-voyager`, voyagerMiddleware({ endpointUrl: example.uri }));
   addToMainPage(example);
 }

package.json

@@ -35,12 +35,12 @@
     "@babel/preset-env": "7.8.4",
     "@babel/preset-flow": "7.8.3",
     "altair-express-middleware": "^2.4.3",
+    "apollo-server-express": "^2.10.1",
     "aws-sdk": "2.619.0",
     "cors": "2.8.5",
     "dedent": "^0.7.0",
     "elasticsearch": "16.6.0",
     "express": "4.17.1",
-    "express-graphql": "0.9.0",
     "graphql": "14.6.0",
     "graphql-compose": "7.12.0",
     "graphql-compose-aws": "4.0.1",
@@ -49,8 +49,9 @@
     "graphql-compose-mongoose": "7.3.4",
     "graphql-compose-pagination": "6.0.3",
     "graphql-compose-relay": "5.0.3",
-    "graphql-playground-middleware-express": "1.7.12",
-    "mongoose": "5.9.1"
+    "graphql-voyager": "^1.0.0-rc.29",
+    "mongoose": "5.9.1",
+    "subscriptions-transport-ws": "^0.9.16"
   },
   "devDependencies": {
     "babel-core": "7.0.0-bridge.0",