Add graphql-ws protocol support (apollographql#2168)

* Implement graphql-transport-ws protocol support
* Add graphql-transport-ws integration test based on Apollo Server docs-examples
* Add CI step for Apollo Server graphql-transport-ws tests
* After installing node v12 switch to use v16
* Instruct nvm to use version in .nvmrc
* Update documentation and tutorial
* Change WSProtocol cases to closer match library names
* Remove initializer defaults and require web socket protocol on designated initializer.
* Update Subscriptions documentation
* Add WSProtocol option for AWS AppSync
* Add ping/pong message support required by graphql-ws
* Update documentation and tutorial
* Add tests for subscriptionWsProtocol
* Add tests for graphqlWSProtocol
* Revert to naming aligned with the protocols and not the implementation libraries
* Use longer async timeout for slower environments like CI
* Fix test names
* Fix project configuration
* Rename protocol parameter on WebSocket initializers
* Revert "Use longer async timeout for slower environments like CI"
* Fix async timing bug and refactor websocket protocol tests

.circleci/config.yml

@@ -31,9 +31,11 @@ commands:
     steps:
       - restore_cache:
           key: starwars-server
+      - restore_cache:
+          key: apollo-server-graphql-transport-ws
       - common_test_setup
       - run:
-          command: ./scripts/install-node.sh
+          command: ./scripts/install-node-v12.sh
           name: Install Node
       - run:
           command: ./scripts/install-or-update-starwars-server.sh
@@ -43,18 +45,29 @@ commands:
           name: Start StarWars Server
           background: true
       - run:
-          command: cd SimpleUploadServer && npm install && npm start
+          command: cd SimpleUploadServer && nvm use && npm install && npm start
           name: Start Upload Server
           background: true
       - run:
           command: sudo chmod -R +rwx SimpleUploadServer
           name: Adjust permissions for simple upload server folder
+      - run:
+          command: ./scripts/install-apollo-server-docs-example-server.sh
+          name: Install Apollo Server (graphql-transport-ws configuration)
+      - run:
+          command: cd ../docs-examples/apollo-server/v3/subscriptions-graphql-ws && npm start
+          name: Start Apollo Server (graphql-transport-ws configuration)
+          background: true
   integration_test_cleanup:
     steps:
       - save_cache:
           key: starwars-server
           paths:
             - ../starwars-server
+      - save_cache:
+          key: apollo-server-graphql-transport-ws
+          paths:
+            - ../docs-examples/apollo-server/v3/subscriptions-graphql-ws
   common_test_setup:
     description: Commands to run for setup of every set of tests
     steps:

Configuration/Apollo/Apollo-Target-SubscriptionAPI.xcconfig

@@ -0,0 +1,3 @@
+#include "../Shared/Workspace-Universal-Framework.xcconfig"
+
+INFOPLIST_FILE = Sources/SubscriptionAPI/Info.plist

SimpleUploadServer/.nvmrc

@@ -0,0 +1 @@
+v12.22.10

SimpleUploadServer/index.js

@@ -64,6 +64,8 @@ const server = new ApolloServer({
   }
 });
 
-server.listen().then(({ url }) => {
+server.listen({
+  port: 4001
+}).then(({ url }) => {
   console.info(`Upload server started at ${url}`);
 });

Sources/ApolloTestSupport/MockWebSocketDelegate.swift

@@ -0,0 +1,18 @@
+import Foundation
+@testable import ApolloWebSocket
+
+public class MockWebSocketDelegate: WebSocketClientDelegate {
+  public var didReceiveMessage: ((String) -> Void)?
+
+  public init() {}
+
+  public func websocketDidConnect(socket: WebSocketClient) {}
+
+  public func websocketDidDisconnect(socket: WebSocketClient, error: Error?) {}
+
+  public func websocketDidReceiveMessage(socket: WebSocketClient, text: String) {
+    didReceiveMessage?(text)
+  }
+
+  public func websocketDidReceiveData(socket: WebSocketClient, data: Data) {}
+}

Sources/ApolloWebSocket/DefaultImplementation/WebSocket.swift

@@ -68,14 +68,30 @@ public final class WebSocket: NSObject, WebSocketClient, StreamDelegate, WebSock
     public let code: Int
   }
 
-  private struct Constants {
+  /// The GraphQL over WebSocket protocols supported by apollo-ios.
+  public enum WSProtocol: CustomStringConvertible {
+    /// WebSocket protocol `graphql-ws`. This is implemented by the [subscriptions-transport-ws](https://github.com/apollographql/subscriptions-transport-ws)
+    /// and AWS AppSync libraries.
+    case graphql_ws
+    /// WebSocket protocol `graphql-transport-ws`. This is implemented by the [graphql-ws](https://github.com/enisdenjo/graphql-ws)
+    /// library.
+    case graphql_transport_ws
+
+    public var description: String {
+      switch self {
+      case .graphql_ws: return "graphql-ws"
+      case .graphql_transport_ws: return "graphql-transport-ws"
+      }
+    }
+  }
+
+  struct Constants {
     static let headerWSUpgradeName     = "Upgrade"
     static let headerWSUpgradeValue    = "websocket"
     static let headerWSHostName        = "Host"
     static let headerWSConnectionName  = "Connection"
     static let headerWSConnectionValue = "Upgrade"
     static let headerWSProtocolName    = "Sec-WebSocket-Protocol"
-    static let headerWSProtocolValue   = "graphql-ws"
     static let headerWSVersionName     = "Sec-WebSocket-Version"
     static let headerWSVersionValue    = "13"
     static let headerWSExtensionName   = "Sec-WebSocket-Extensions"
@@ -183,8 +199,12 @@ public final class WebSocket: NSObject, WebSocketClient, StreamDelegate, WebSock
     return canWork
   }
 
-  /// Used for setting protocols.
-  public init(request: URLRequest) {
+  /// Designated initializer.
+  ///
+  /// - Parameters:
+  ///   - request: A URL request object that provides request-specific information such as the URL.
+  ///   - protocol: Protocol to use for communication over the web socket.
+  public init(request: URLRequest, protocol: WSProtocol) {
     self.request = request
     self.stream = FoundationStream()
     if request.value(forHTTPHeaderField: Constants.headerOriginName) == nil {
@@ -197,20 +217,36 @@ public final class WebSocket: NSObject, WebSocketClient, StreamDelegate, WebSock
       self.request.setValue(origin, forHTTPHeaderField: Constants.headerOriginName)
     }
 
-    self.request.setValue(Constants.headerWSProtocolValue,
-                          forHTTPHeaderField: Constants.headerWSProtocolName)
+    self.request.setValue(`protocol`.description, forHTTPHeaderField: Constants.headerWSProtocolName)
+
     writeQueue.maxConcurrentOperationCount = 1
   }
 
-  public convenience init(url: URL) {
+  /// Convenience initializer to specify the URL and web socket protocol.
+  ///
+  /// - Parameters:
+  ///   - url: The destination URL to connect to.
+  ///   - protocol: Protocol to use for communication over the web socket.
+  public convenience init(url: URL, protocol: WSProtocol) {
     var request = URLRequest(url: url)
     request.timeoutInterval = 5
-    self.init(request: request)
+
+    self.init(request: request, protocol: `protocol`)
   }
 
-  // Used for specifically setting the QOS for the write queue.
-  public convenience init(url: URL, writeQueueQOS: QualityOfService) {
-    self.init(url: url)
+  /// Convenience initializer to specify the URL and web socket protocol with a specific quality of
+  /// service on the write queue.
+  ///
+  /// - Parameters:
+  ///   - url: The destination URL to connect to.
+  ///   - writeQueueQOS: Specifies the quality of service for the write queue.
+  ///   - protocol: Protocol to use for communication over the web socket.
+  public convenience init(
+    url: URL,
+    writeQueueQOS: QualityOfService,
+    protocol: WSProtocol
+  ) {
+    self.init(url: url, protocol: `protocol`)
     writeQueue.qualityOfService = writeQueueQOS
   }
 

Sources/ApolloWebSocket/OperationMessage.swift

@@ -7,6 +7,7 @@ final class OperationMessage {
   enum Types : String {
     case connectionInit = "connection_init"            // Client -> Server
     case connectionTerminate = "connection_terminate"  // Client -> Server
+    case subscribe = "subscribe"                       // Client -> Server
     case start = "start"                               // Client -> Server
     case stop = "stop"                                 // Client -> Server
 
@@ -17,6 +18,10 @@ final class OperationMessage {
     case data = "data"                                 // Server -> Client
     case error = "error"                               // Server -> Client
     case complete = "complete"                         // Server -> Client
+    case next = "next"                                 // Server -> Client
+
+    case ping = "ping"                                 // Bidirectional
+    case pong = "pong"                                 // Bidirectional
   }
 
   let serializationFormat = JSONSerializationFormat.self
@@ -34,7 +39,7 @@ final class OperationMessage {
 
   init(payload: GraphQLMap? = nil,
        id: String? = nil,
-       type: Types = .start) {
+       type: Types) {
     var message: GraphQLMap = [:]
     if let payload = payload {
       message["payload"] = payload
@@ -99,6 +104,12 @@ final class OperationMessage {
   }
 }
 
+extension OperationMessage: CustomDebugStringConvertible {
+  var debugDescription: String {
+    rawMessage!
+  }
+}
+
 struct ParseHandler {
   let type: String?
   let id: String?

Sources/ApolloWebSocket/WebSocketTransport.swift

@@ -145,6 +145,7 @@ public class WebSocketTransport {
 
       switch messageType {
       case .data,
+           .next,
            .error:
         if let id = parseHandler.id, let responseHandler = subscribers[id] {
           if let payload = parseHandler.payload {
@@ -180,11 +181,19 @@ public class WebSocketTransport {
         writeQueue()
 
       case .connectionKeepAlive,
-           .startAck:
+           .startAck,
+           .pong:
         writeQueue()
 
+      case .ping:
+        if let str = OperationMessage(type: .pong).rawMessage {
+          write(str)
+          writeQueue()
+        }
+
       case .connectionInit,
            .connectionTerminate,
+           .subscribe,
            .start,
            .stop,
            .connectionError:
@@ -270,7 +279,13 @@ public class WebSocketTransport {
                                               sendQueryDocument: true,
                                               autoPersistQuery: false)
     let identifier = operationMessageIdCreator.requestId()
-    guard let message = OperationMessage(payload: body, id: identifier).rawMessage else {
+
+    var type: OperationMessage.Types = .start
+    if case WebSocket.WSProtocol.graphql_transport_ws.description = websocket.request.value(forHTTPHeaderField: WebSocket.Constants.headerWSProtocolName) {
+      type = .subscribe
+    }
+
+    guard let message = OperationMessage(payload: body, id: identifier, type: type).rawMessage else {
       return nil
     }
 

Sources/SubscriptionAPI/API.swift

@@ -0,0 +1,51 @@
+// @generated
+//  This file was automatically generated and should not be edited.
+
+import Apollo
+import Foundation
+
+public final class IncrementingSubscription: GraphQLSubscription {
+  /// The raw GraphQL definition of this operation.
+  public let operationDefinition: String =
+    """
+    subscription Incrementing {
+      numberIncremented
+    }
+    """
+
+  public let operationName: String = "Incrementing"
+
+  public let operationIdentifier: String? = "fe12b5f0dfc7fefa513cc8aecef043b45daf2d776fd000d3a7703f9798ecf233"
+
+  public init() {
+  }
+
+  public struct Data: GraphQLSelectionSet {
+    public static let possibleTypes: [String] = ["Subscription"]
+
+    public static var selections: [GraphQLSelection] {
+      return [
+        GraphQLField("numberIncremented", type: .scalar(Int.self)),
+      ]
+    }
+
+    public private(set) var resultMap: ResultMap
+
+    public init(unsafeResultMap: ResultMap) {
+      self.resultMap = unsafeResultMap
+    }
+
+    public init(numberIncremented: Int? = nil) {
+      self.init(unsafeResultMap: ["__typename": "Subscription", "numberIncremented": numberIncremented])
+    }
+
+    public var numberIncremented: Int? {
+      get {
+        return resultMap["numberIncremented"] as? Int
+      }
+      set {
+        resultMap.updateValue(newValue, forKey: "numberIncremented")
+      }
+    }
+  }
+}

Sources/SubscriptionAPI/Info.plist

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>en</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>FMWK</string>
+	<key>CFBundleShortVersionString</key>
+	<string>$(CURRENT_PROJECT_VERSION)</string>
+	<key>CFBundleVersion</key>
+	<string>$(CURRENT_PROJECT_VERSION)</string>
+	<key>NSPrincipalClass</key>
+	<string></string>
+</dict>
+</plist>

Sources/SubscriptionAPI/SubscriptionAPI.h

@@ -0,0 +1,11 @@
+#import <Foundation/Foundation.h>
+
+//! Project version number for SubscriptionAPI.
+FOUNDATION_EXPORT double SubscriptionAPIVersionNumber;
+
+//! Project version string for SubscriptionAPI.
+FOUNDATION_EXPORT const unsigned char SubscriptionAPIVersionString[];
+
+// In this header, you should import all the public headers of your framework using statements like #import <SubscriptionAPI/PublicHeader.h>
+
+

Sources/SubscriptionAPI/graphql/operation_ids.json

@@ -0,0 +1,6 @@
+{
+  "fe12b5f0dfc7fefa513cc8aecef043b45daf2d776fd000d3a7703f9798ecf233": {
+    "name": "Incrementing",
+    "source": "subscription Incrementing {\n  numberIncremented\n}"
+  }
+}

Sources/SubscriptionAPI/graphql/schema.graphqls

@@ -0,0 +1,7 @@
+type Query {
+  currentNumber: Int
+}
+
+type Subscription {
+  numberIncremented: Int
+}

Sources/SubscriptionAPI/graphql/subscription.graphql

@@ -0,0 +1,4 @@
+subscription Incrementing {
+  numberIncremented
+}
+