feature: Makes connection_init payload type generic

This allows the user to define their own authorization types, but still allows us to encode/decode in a strongly typed way.

Some common default payload types are included.

Author: NeedleInAJayStack

Sources/GraphQLWS/Client.swift

@@ -4,7 +4,7 @@ import Foundation
 import GraphQL
 
 /// Client is an open-ended implementation of the client side of the protocol. It parses and adds callbacks for each type of server respose.
-public class Client {
+public class Client<InitPayload: Equatable & Codable> {
     // We keep this weak because we strongly inject this object into the messenger callback
     weak var messenger: Messenger?
 
@@ -136,7 +136,7 @@ public class Client {
     }
 
     /// Send a `connection_init` request through the messenger
-    public func sendConnectionInit(payload: ConnectionInitAuth?) {
+    public func sendConnectionInit(payload: InitPayload) {
         guard let messenger = messenger else { return }
         messenger.send(
             ConnectionInitRequest(

Sources/GraphQLWS/InitPayloads.swift

@@ -0,0 +1,9 @@
+// Contains convenient `connection_init` payloads for users of this package
+
+/// `connection_init` `payload` that is empty
+public struct EmptyInitPayload: Equatable & Codable { }
+
+/// `connection_init` `payload` that includes an `authToken` field
+public struct TokenInitPayload: Equatable & Codable {
+    let authToken: String
+}

Sources/GraphQLWS/Requests.swift

@@ -20,19 +20,9 @@ struct Request: Equatable, JsonEncodable {
 }
 
 /// A websocket `connection_init` request from the client to the server
-public struct ConnectionInitRequest: Equatable, JsonEncodable {
+public struct ConnectionInitRequest<InitPayload: Codable & Equatable>: Equatable, JsonEncodable {
     var type = RequestMessageType.GQL_CONNECTION_INIT
-    public let payload: ConnectionInitAuth?
-}
-
-// TODO: Make this structure user-defined
-/// Authorization format for a websocket `connection_init` request from the client to the server
-public struct ConnectionInitAuth: Equatable, JsonEncodable {
-    public let authToken: String
-    
-    public init(authToken: String) {
-        self.authToken = authToken
-    }
+    let payload: InitPayload
 }
 
 /// A websocket `start` request from the client to the server

Sources/GraphQLWS/Server.swift

@@ -7,14 +7,14 @@ import NIO
 import RxSwift
 
 /// Server implements the server-side portion of the protocol, allowing a few callbacks for customization.
-public class Server {
+public class Server<InitPayload: Equatable & Codable> {
     // We keep this weak because we strongly inject this object into the messenger callback
     weak var messenger: Messenger?
 
     let onExecute: (GraphQLRequest) -> EventLoopFuture<GraphQLResult>
     let onSubscribe: (GraphQLRequest) -> EventLoopFuture<SubscriptionResult>
 
-    var auth: (ConnectionInitRequest) throws -> Void = { _ in }
+    var auth: (InitPayload) throws -> Void = { _ in }
     var onExit: () -> Void = { }
     var onMessage: (String) -> Void = { _ in }
 
@@ -66,7 +66,7 @@ public class Server {
 
             switch request.type {
                 case .GQL_CONNECTION_INIT:
-                    guard let connectionInitRequest = try? self.decoder.decode(ConnectionInitRequest.self, from: json) else {
+                    guard let connectionInitRequest = try? self.decoder.decode(ConnectionInitRequest<InitPayload>.self, from: json) else {
                         self.error(.invalidRequestFormat(messageType: .GQL_CONNECTION_INIT))
                         return
                     }
@@ -96,9 +96,9 @@ public class Server {
     }
 
     /// Define the callback run during `connection_init` resolution that allows authorization using the `payload`.
-    /// Throw to indicate that authorization has failed.
+    /// Throw from this closure to indicate that authorization has failed.
     /// - Parameter callback: The callback to assign
-    public func auth(_ callback: @escaping (ConnectionInitRequest) throws -> Void) {
+    public func auth(_ callback: @escaping (InitPayload) throws -> Void) {
         self.auth = callback
     }
 
@@ -114,14 +114,14 @@ public class Server {
         self.onMessage = callback
     }
 
-    private func onConnectionInit(_ connectionInitRequest: ConnectionInitRequest, _ messenger: Messenger) {
+    private func onConnectionInit(_ connectionInitRequest: ConnectionInitRequest<InitPayload>, _ messenger: Messenger) {
         guard !initialized else {
             self.error(.tooManyInitializations())
             return
         }
 
         do {
-            try self.auth(connectionInitRequest)
+            try self.auth(connectionInitRequest.payload)
         }
         catch {
             self.error(.unauthorized())

Tests/GraphQLWSTests/GraphQLWSTests.swift

@@ -11,7 +11,7 @@ import XCTest
 class GraphqlWsTests: XCTestCase {
     var clientMessenger: TestMessenger!
     var serverMessenger: TestMessenger!
-    var server: Server!
+    var server: Server<TokenInitPayload>!
 
     override func setUp() {
         clientMessenger = TestMessenger()
@@ -24,7 +24,7 @@ class GraphqlWsTests: XCTestCase {
         let api = TestAPI()
         let context = TestContext()
 
-        server = Server(
+        server = Server<TokenInitPayload>(
             messenger: serverMessenger,
             onExecute: { graphQLRequest in
                 api.execute(
@@ -48,7 +48,7 @@ class GraphqlWsTests: XCTestCase {
         var messages = [String]()
         let completeExpectation = XCTestExpectation()
 
-        let client = Client(messenger: clientMessenger)
+        let client = Client<TokenInitPayload>(messenger: clientMessenger)
         client.onMessage { message, _ in
             messages.append(message)
             completeExpectation.fulfill()
@@ -81,14 +81,14 @@ class GraphqlWsTests: XCTestCase {
         var messages = [String]()
         let completeExpectation = XCTestExpectation()
 
-        let client = Client(messenger: clientMessenger)
+        let client = Client<TokenInitPayload>(messenger: clientMessenger)
         client.onMessage { message, _ in
             messages.append(message)
             completeExpectation.fulfill()
         }
 
         client.sendConnectionInit(
-            payload: ConnectionInitAuth(
+            payload: TokenInitPayload(
                 authToken: ""
             )
         )
@@ -100,14 +100,15 @@ class GraphqlWsTests: XCTestCase {
         )
     }
 
+    /// Test single op message flow works as expected
     func testSingleOp() throws {
         let id = UUID().description
 
         // Test single-op conversation
         var messages = [String]()
         let completeExpectation = XCTestExpectation()
 
-        let client = Client(messenger: clientMessenger)
+        let client = Client<TokenInitPayload>(messenger: clientMessenger)
 
         client.onConnectionAck { _, client in
             client.sendStart(
@@ -131,7 +132,7 @@ class GraphqlWsTests: XCTestCase {
             messages.append(message)
         }
 
-        client.sendConnectionInit(payload: ConnectionInitAuth(authToken: ""))
+        client.sendConnectionInit(payload: TokenInitPayload(authToken: ""))
 
         wait(for: [completeExpectation], timeout: 2)
         XCTAssertEqual(
@@ -141,6 +142,7 @@ class GraphqlWsTests: XCTestCase {
         )
     }
 
+    /// Test streaming message flow works as expected
     func testStreaming() throws {
         let id = UUID().description
 
@@ -151,7 +153,7 @@ class GraphqlWsTests: XCTestCase {
         var dataIndex = 1
         let dataIndexMax = 3
 
-        let client = Client(messenger: clientMessenger)
+        let client = Client<TokenInitPayload>(messenger: clientMessenger)
         client.onConnectionAck { _, client in
             client.sendStart(
                 payload: GraphQLRequest(
@@ -187,7 +189,7 @@ class GraphqlWsTests: XCTestCase {
             messages.append(message)
         }
 
-        client.sendConnectionInit(payload: ConnectionInitAuth(authToken: ""))
+        client.sendConnectionInit(payload: TokenInitPayload(authToken: ""))
 
         wait(for: [completeExpectation], timeout: 2)
         XCTAssertEqual(