fix(subs): allow additional server variations (e.g., Tls, Http2)

CHANGELOG.md

@@ -9,7 +9,7 @@ The version headers in this history reflect the versions of Apollo Server itself
 
 > The changes noted within this `vNEXT` section have not been released yet.  New PRs and commits which introduce changes should include an entry in this `vNEXT` section as part of their development.  With few exceptions, the format of the entry should follow convention (i.e., prefix with package name, use markdown `backtick formatting` for package names and code, suffix with a link to the change-set à la `[PR #YYY](https://link/pull/YYY)`, etc.).  When a release is being prepared, a new header will be (manually) created below and the appropriate changes within that release will be moved into the new section.
 
-- _Nothing yet! Stay tuned!_
+- subscriptions: Fix bug which prevented `installSubscriptionHandlers` from accepting a `websocket.Server` (as intended in [PR #1966](https://github.com/apollographql/apollo-server/pull/1966)) and also added support for other `http.Server` variations (e.g., Tls). [Issue #4198](https://github.com/apollographql/apollo-server/issues/4198) [PR #4200](https://github.com/apollographql/apollo-server/pull/4200)
 
 ## v2.16.1
 

packages/apollo-server-core/src/ApolloServer.ts

@@ -3,7 +3,11 @@ import {
   addMockFunctionsToSchema,
   GraphQLParseOptions,
 } from 'graphql-tools';
+import { Server as NetServer } from 'net'
+import { Server as TlsServer } from 'tls'
 import { Server as HttpServer } from 'http';
+import { Http2Server, Http2SecureServer } from 'http2';
+import { Server as HttpsServer } from 'https';
 import loglevel from 'loglevel';
 import {
   execute,
@@ -602,7 +606,7 @@ export class ApolloServerBase {
     }
   }
 
-  public installSubscriptionHandlers(server: HttpServer | WebSocket.Server) {
+  public installSubscriptionHandlers(server: HttpServer | HttpsServer | Http2Server | Http2SecureServer | WebSocket.Server) {
     if (!this.subscriptionServerOptions) {
       if (this.config.gateway) {
         throw Error(
@@ -678,12 +682,12 @@ export class ApolloServerBase {
         keepAlive,
         validationRules: this.requestOptions.validationRules
       },
-      server instanceof WebSocket.Server
-        ? server
-        : {
-            server,
-            path,
-          },
+      server instanceof NetServer || server instanceof TlsServer
+        ? {
+          server,
+          path,
+        }
+        : server
     );
   }
 

packages/apollo-server-integration-testsuite/src/ApolloServer.ts

@@ -2041,6 +2041,87 @@ export function testApolloServer<AS extends ApolloServerBase>(
           })
           .catch(done.fail);
       });
+
+      it('takes websocket server subscriptions configuration', done => {
+        const onConnect = jest.fn(connectionParams => ({
+          ...connectionParams,
+        }));
+        const typeDefs = gql`
+          type Query {
+            hi: String
+          }
+
+          type Subscription {
+            num: Int
+          }
+        `;
+
+        const query = `
+        subscription {
+          num
+        }
+      `;
+
+        const resolvers = {
+          Query: {
+            hi: () => 'here to placate graphql-js',
+          },
+          Subscription: {
+            num: {
+              subscribe: () => {
+                createEvent(1);
+                createEvent(2);
+                createEvent(3);
+                return pubsub.asyncIterator(SOMETHING_CHANGED_TOPIC);
+              },
+            },
+          },
+        };
+
+        const path = '/sub';
+        createApolloServer({
+          typeDefs,
+          resolvers,
+          subscriptions: { onConnect, path },
+        })
+          .then(({ port, server }) => {
+            const subPort = (typeof port === "number" ? port : parseInt(port)) + 1
+            const websocketServer = new WebSocket.Server({port: subPort})
+            server.installSubscriptionHandlers(websocketServer);
+            expect(onConnect).not.toBeCalled();
+
+            expect(server.subscriptionsPath).toEqual(path);
+            const client = new SubscriptionClient(
+              `ws://localhost:${subPort}${server.subscriptionsPath}`,
+              {},
+              WebSocket,
+            );
+
+            const observable = client.request({ query });
+
+            let i = 1;
+            subscription = observable.subscribe({
+              next: ({ data }) => {
+                try {
+                  expect(onConnect).toHaveBeenCalledTimes(1);
+                  expect(data.num).toEqual(i);
+                  if (i === 3) {
+                    done();
+                  }
+                  i++;
+                } catch (e) {
+                  done.fail(e);
+                }
+              },
+              error: done.fail,
+              complete: () => {
+                done.fail(new Error('should not complete'));
+              },
+            });
+          })
+          .catch(done.fail);
+      });
+
       it('allows introspection when introspection is enabled on ApolloServer', done => {
         const typeDefs = gql`
           type Query {