feat(server): add a subscriptions server (#1397)

Author: Jason Kuhrt

package.json

@@ -61,7 +61,7 @@
     "prismjs": "^1.20.0",
     "prompts": "^2.3.0",
     "rxjs": "^6.5.4",
-    "setset": "^0.0.3",
+    "setset": "^0.0.4",
     "simple-git": "^2.0.0",
     "slash": "^3.0.0",
     "source-map-support": "^0.5.19",

src/runtime/server/server.ts

@@ -1,7 +1,8 @@
+import chalk from 'chalk'
 import createExpress, { Express } from 'express'
-import { GraphQLError, GraphQLSchema } from 'graphql'
+import { GraphQLSchema } from 'graphql'
 import * as HTTP from 'http'
-import { HttpError } from 'http-errors'
+import { isEmpty } from 'lodash'
 import * as Net from 'net'
 import * as Plugin from '../../lib/plugin'
 import { httpClose, httpListen, noop } from '../../lib/utils'
@@ -47,13 +48,15 @@ interface State {
   httpServer: HTTP.Server
   createContext: null | (() => ContextAdder)
   apolloServer: null | ApolloServerExpress
+  enableSubscriptionsServer: boolean
 }
 
 export const defaultState = {
   running: false,
   httpServer: HTTP.createServer(),
   createContext: null,
   apolloServer: null,
+  enableSubscriptionsServer: false,
 }
 
 export function create(appState: AppState) {
@@ -106,9 +109,43 @@ export function create(appState: AppState) {
           loadedRuntimePlugins
         )
 
+        /**
+         * Resolve if subscriptions are enabled or not
+         */
+
+        if (settings.metadata.fields.subscriptions.fields.enabled.from === 'change') {
+          state.enableSubscriptionsServer = settings.data.subscriptions.enabled
+          /**
+           * Validate the integration of server subscription settings and the schema subscription type definitions.
+           */
+          if (hasSubscriptionFields(schema)) {
+            if (!settings.data.subscriptions.enabled) {
+              log.error(
+                `You have disabled server subscriptions but your schema has a ${chalk.yellowBright(
+                  'Subscription'
+                )} type with fields present. When your API clients send subscription operations at runtime they will fail.`
+              )
+            }
+          } else if (settings.data.subscriptions.enabled) {
+            log.warn(
+              `You have enabled server subscriptions but your schema has no ${chalk.yellowBright(
+                'Subscription'
+              )} type with fields.`
+            )
+          }
+        } else if (hasSubscriptionFields(schema)) {
+          state.enableSubscriptionsServer = true
+        }
+
+        /**
+         * Setup Apollo Server
+         */
+
         state.apolloServer = new ApolloServerExpress({
           schema,
           engine: settings.data.apollo.engine.enabled ? settings.data.apollo.engine : false,
+          // todo expose options
+          subscriptions: settings.data.subscriptions,
           context: createContext,
           introspection: settings.data.graphql.introspection,
           formatError: errorFormatter,
@@ -127,6 +164,10 @@ export function create(appState: AppState) {
           cors: settings.data.cors,
         })
 
+        if (state.enableSubscriptionsServer) {
+          state.apolloServer.installSubscriptionHandlers(state.httpServer)
+        }
+
         return { createContext }
       },
       async start() {
@@ -143,7 +184,10 @@ export function create(appState: AppState) {
           port: address.port,
           host: address.address,
           ip: address.address,
-          path: settings.data.path,
+          paths: {
+            graphql: settings.data.path,
+            graphqlSubscrtipions: state.enableSubscriptionsServer ? settings.data.subscriptions.path : null,
+          },
         })
         DevMode.sendServerReadySignalToDevModeMaster()
       },
@@ -163,27 +207,6 @@ export function create(appState: AppState) {
   return internalServer
 }
 
-/**
- * Log http errors during development.
- */
-const wrapHandlerWithErrorHandling = (handler: NexusRequestHandler): NexusRequestHandler => {
-  return async (req, res) => {
-    await handler(req, res)
-    if (res.statusCode !== 200 && (res as any).error) {
-      const error: HttpError = (res as any).error
-      const graphqlErrors: GraphQLError[] = error.graphqlErrors
-
-      if (graphqlErrors.length > 0) {
-        graphqlErrors.forEach(errorFormatter)
-      } else {
-        log.error(error.message, {
-          error,
-        })
-      }
-    }
-  }
-}
-
 /**
  * Combine all the context contributions defined in the app and in plugins.
  */
@@ -217,3 +240,7 @@ function createContextCreator(
 
   return createContext
 }
+
+function hasSubscriptionFields(schema: GraphQLSchema): boolean {
+  return !isEmpty(schema.getSubscriptionType()?.getFields())
+}

src/runtime/server/settings.ts

@@ -1,3 +1,4 @@
+import { SubscriptionServerOptions } from 'apollo-server-core'
 import { PlaygroundRenderPageOptions } from 'apollo-server-express'
 import { CorsOptions as OriginalCorsOption } from 'cors'
 import * as Setset from 'setset'
@@ -37,7 +38,38 @@ export type PlaygroundLonghandInput = {
   settings?: Omit<Partial<Exclude<PlaygroundRenderPageOptions['settings'], undefined>>, 'general.betaUpdates'>
 }
 
+type SubscriptionsLonghandInput = Omit<SubscriptionServerOptions, 'path'> & {
+  /**
+   * The path for clients to send subscriptions to.
+   *
+   * @default "/graphql"
+   */
+  path?: string
+  /**
+   * Disable or enable the subscriptions server.
+   *
+   * @dynamicDefault
+   *
+   * - true if there is a Subscription type in your schema
+   * - false otherwise
+   */
+  enabled?: boolean
+}
+
 export type SettingsInput = {
+  /**
+   * Configure the subscriptions server.
+   *
+   * - Pass true to force enable with setting defaults
+   * - Pass false to force disable
+   * - Pass settings to customize config. Note does not imply enabled. Set "enabled: true" for that or rely on default.
+   *
+   * @dynamicDefault
+   *
+   * - true if there is a Subscription type in your schema
+   * - false otherwise
+   */
+  subscriptions?: boolean | SubscriptionsLonghandInput
   /**
    * Port the server should be listening on.
    *
@@ -190,7 +222,7 @@ export type SettingsInput = {
    * Create a message suitable for printing to the terminal about the server
    * having been booted.
    */
-  startMessage?: (address: { port: number; host: string; ip: string; path: string }) => void
+  startMessage?: (startInfo: ServerStartInfo) => void
   /**
    * todo
    */
@@ -199,9 +231,25 @@ export type SettingsInput = {
   }
 }
 
-export type SettingsData = Setset.InferDataFromInput<Omit<SettingsInput, 'host' | 'cors' | 'apollo'>> & {
+type ServerStartInfo = {
+  port: number
+  host: string
+  ip: string
+  paths: {
+    graphql: string
+    graphqlSubscrtipions: null | string
+  }
+}
+
+export type SettingsData = Setset.InferDataFromInput<
+  Omit<SettingsInput, 'host' | 'cors' | 'apollo' | 'subscriptions'>
+> & {
   host?: string
   cors: ResolvedOptional<SettingsInput['cors']>
+  subscriptions: Omit<SubscriptionsLonghandInput, 'enabled' | 'path'> & {
+    enabled: boolean
+    path: string
+  }
   apollo: {
     engine: ApolloConfigEngine & {
       enabled: boolean
@@ -212,6 +260,28 @@ export type SettingsData = Setset.InferDataFromInput<Omit<SettingsInput, 'host'
 export const createServerSettingsManager = () =>
   Setset.create<SettingsInput, SettingsData>({
     fields: {
+      subscriptions: {
+        shorthand(enabled) {
+          return { enabled }
+        },
+        fields: {
+          path: {
+            initial() {
+              return '/graphql'
+            },
+          },
+          keepAlive: {},
+          onConnect: {},
+          onDisconnect: {},
+          enabled: {
+            initial() {
+              // This is not accurate. The default is actually dynamic depending
+              // on if the user has defined any subscription type or not.
+              return true
+            },
+          },
+        },
+      },
       apollo: {
         fields: {
           engine: {
@@ -350,9 +420,14 @@ export const createServerSettingsManager = () =>
       },
       startMessage: {
         initial() {
-          return ({ port, host, path }): void => {
+          return ({ port, host, paths }): void => {
+            const url = `http://${Utils.prettifyHost(host)}:${port}${paths.graphql}`
+            const subscrtipionsURL = paths.graphqlSubscrtipions
+              ? `http://${Utils.prettifyHost(host)}:${port}${paths.graphqlSubscrtipions}`
+              : null
             serverLogger.info('listening', {
-              url: `http://${Utils.prettifyHost(host)}:${port}${path}`,
+              url,
+              subscrtipionsURL,
             })
           }
         },

yarn.lock

@@ -5682,10 +5682,10 @@ [email protected]:
   resolved "https://registry.yarnpkg.com/setprototypeof/-/setprototypeof-1.1.1.tgz#7e95acb24aa92f5885e0abef5ba131330d4ae683"
   integrity sha512-JvdAWfbXeIGaZ9cILp38HntZSFSo3mWg6xGcJJsd+d4aRMOqauag1C63dJfDw7OaMYwEbHMOxEZ1lqVRYP2OAw==
 
-setset@^0.0.3:
-  version "0.0.3"
-  resolved "https://registry.yarnpkg.com/setset/-/setset-0.0.3.tgz#b071ddfeaf257ecb6148aa8a1187eb1ef5360826"
-  integrity sha512-rty4d5o1LVjA5Ct4fUAH0MeHfKNZTLxM409j68KLg8zd25Fb9tBAHjB5xeP9mK/qUtwCSH/ScYdpB0vGMo7dhg==
+setset@^0.0.4:
+  version "0.0.4"
+  resolved "https://registry.yarnpkg.com/setset/-/setset-0.0.4.tgz#93ebc4e091d6435151deea5b200ea238e71b6466"
+  integrity sha512-4y8ju0HCfyZybvaLvFzuwF8GWhetQWNQOyx/sclP/bHa0m2zahpXsnszmJSGAS6l/xVfnCD3VJO/eToAGfmAOQ==
   dependencies:
     "@jsdevtools/ono" "^7.1.3"
     "@nexus/logger" "^0.2.0"