feat: update next handling to user GraphQLResults

Author: Garrett Moseke

Sources/GraphQLTransportWS/Client.swift

@@ -144,12 +144,12 @@ public class Client<InitPayload: Equatable & Codable> {
 
     /// Add an observable object for this client that will fire off `Next` messages to the server as updates happen.
     /// - Parameter observable: `Observable<EventLoopFuture<GraphQLRequest>>` to subscribe to for changes.
-    public func addObservable(observable: Observable<EventLoopFuture<GraphQLRequest>>) {
+    public func addObservableSubscription(observable: Observable<EventLoopFuture<GraphQLResult>>) {
         observable.subscribe(
             onNext: { [weak self] resultFuture in
                 guard let self = self else { return }
-                resultFuture.whenSuccess { request in
-                    self.sendNext(payload: request, id: UUID().uuidString)
+                resultFuture.whenSuccess { result in
+                    self.sendNext(payload: result, id: UUID().uuidString)
                 }
                 resultFuture.whenFailure { error in
                     self.error(.graphQLError(error))
@@ -162,11 +162,11 @@ public class Client<InitPayload: Equatable & Codable> {
     /// - Parameters:
     ///   - payload: `GraphQLRequest` object for the server to handle
     ///   - id: id of the message
-    private func sendNext(payload: GraphQLRequest, id: String) {
+    private func sendNext(payload: GraphQLResult, id: String) {
         guard let messenger = messenger else { return }
         messenger.send(
-            NextRequest(
-                payload: payload,
+            NextResponse(
+                payload,
                 id: id
             ).toJSON(encoder)
         )

Sources/GraphQLTransportWS/Requests.swift

@@ -30,13 +30,6 @@ struct SubscribeRequest: Equatable, JsonEncodable {
     let id: String
 }
 
-/// A websocket `next` request from the client to the server
-public struct NextRequest: Equatable, JsonEncodable {
-    var type = RequestMessageType.next
-    let payload: GraphQLRequest
-    let id: String
-}
-
 /// A websocket `complete` request from the client to the server
 struct CompleteRequest: Equatable, JsonEncodable {
     var type = RequestMessageType.complete

Sources/GraphQLTransportWS/Server.swift

@@ -19,7 +19,7 @@ public class Server<InitPayload: Equatable & Codable> {
     var onOperationComplete: (String) -> Void = { _ in }
     var onOperationError: (String) -> Void = { _ in }
     var onMessage: (String) -> Void = { _ in }
-    var onNext: (NextRequest, Server) -> Void = { _, _ in }
+    var onNext: (NextResponse, Server) -> Void = { _, _ in }
 
     var initialized = false
 
@@ -89,25 +89,15 @@ public class Server<InitPayload: Equatable & Codable> {
                     self.error(.invalidType())
                 // Addition for Datasync: Servers may now receive "next" responses from clients
                 case .next:
-                    guard let nextRequest = try? self.decoder.decode(NextRequest.self, from: data) else {
-                        self.error(.invalidRequestFormat(messageType: .next))
+                    guard self.initialized else {
+                        self.error(.notInitialized())
                         return
                     }
-                    do {
-                        if try nextRequest.payload.isSubscription() {
-                            self
-                                .error(.init(
-                                    "Cannot initialize a subscription within another subscription. Payload must be query or mutation",
-                                    code: .invalidRequestFormat
-                                ))
-                        }
-                        else {
-                            self.onNext(nextRequest, self)
-                        }
-                    }
-                    catch {
-                        self.error(.graphQLError(error))
+                    guard let nextMessage = try? self.decoder.decode(NextResponse.self, from: data) else {
+                        self.error(.invalidRequestFormat(messageType: .next))
+                        return
                     }
+                    self.onNext(nextMessage, self)
             }
         }
     }
@@ -149,7 +139,7 @@ public class Server<InitPayload: Equatable & Codable> {
     /// can now define custom handling for frames containing `GraphQLResult`
     /// objects sent by the client.
     /// - Parameter callback: The callback to assign
-    public func onNext(_ callback: @escaping (NextRequest, Server) -> Void) {
+    public func onNext(_ callback: @escaping (NextResponse, Server) -> Void) {
         self.onNext = callback
     }
 

Tests/GraphQLTransportWSTests/GraphQLTransportWSTests.swift

@@ -213,7 +213,7 @@ final class GraphqlTransportWSTests: XCTestCase {
 
         let client = Client<TokenInitPayload>(messenger: clientMessenger)
         client.onConnectionAck { _, client in
-            client.addObservable(observable: testObservable(loop: self.eventLoop))
+            client.addObservableSubscription(observable: testObservable(loop: self.eventLoop))
         }
 
         client.onError { _, _ in
@@ -273,7 +273,7 @@ final class GraphqlTransportWSTests: XCTestCase {
             pubsub.onNext("hello \(dataIndex)")
 
             // Once the subscription has begun send a `next` frame from the client as well
-            client.addObservable(observable: testObservable(loop: self.eventLoop))
+            client.addObservableSubscription(observable: testObservable(loop: self.eventLoop))
         }
 
         client.onNext { _, _ in
@@ -322,34 +322,26 @@ final class GraphqlTransportWSTests: XCTestCase {
         )
     }
 
-    func testDisallowedNestedSubscriptions() throws {
+    func testNextUninitialized() throws {
         var messages = [String]()
         let completeExpectation = XCTestExpectation()
-        completeExpectation.expectedFulfillmentCount = 2
 
         let client = Client<TokenInitPayload>(messenger: clientMessenger)
-        client.onConnectionAck { _, client in
-            client.addObservable(observable: testObservable(loop: self.eventLoop, sendAsSubscription: true))
-        }
 
         client.onMessage { message, _ in
             messages.append(message)
             completeExpectation.fulfill()
         }
 
-        client.sendConnectionInit(
-            payload: TokenInitPayload(
-                authToken: ""
-            )
-        )
+        client.addObservableSubscription(observable: testObservable(loop: self.eventLoop))
 
         wait(for: [completeExpectation], timeout: 2)
         XCTAssertEqual(
             messages.count,
-            2, // 1 connection_ack, 1 error
+            1, // 1 error
             "Messages: \(messages.description)"
         )
-        XCTAssertTrue(try XCTUnwrap(messages.last).contains(ErrorCode.invalidRequestFormat.rawValue.description))
+        XCTAssertTrue(try XCTUnwrap(messages.last).contains(ErrorCode.notInitialized.rawValue.description))
     }
 
     enum TestError: Error {

Tests/GraphQLTransportWSTests/Utils/TestAPI.swift

@@ -39,22 +39,9 @@ struct TestResolver {
     }
 }
 
-func testObservable(loop: EventLoop, sendAsSubscription: Bool = false) -> Observable<EventLoopFuture<GraphQLRequest>> {
+func testObservable(loop: EventLoop) -> Observable<EventLoopFuture<GraphQLResult>> {
     return Observable.create { observer in
-        observer.on(.next(loop.makeSucceededFuture(GraphQLRequest(
-            query:
-            sendAsSubscription ?
-                """
-                subscription {
-                    hello
-                }
-                """ :
-                """
-                query {
-                    hello
-                }
-                """
-        ))))
+        observer.on(.next(loop.makeSucceededFuture(GraphQLResult(data: ["Some Data": "For you"], errors: []))))
         return Disposables.create()
     }
 }