Merge pull request #1002 from WalletConnect/handle-fallback

[Dispatcher] Handle fallback to .org
WalletConnect · Aug 1, 2023 · 7bae06f · 7bae06f
2 parents e51e0a4 + dce1166
commit 7bae06f
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Showing 5 changed files with 40 additions and 9 deletions.
diff --git a/Example/RelayIntegrationTests/RelayClientEndToEndTests.swift b/Example/RelayIntegrationTests/RelayClientEndToEndTests.swift
@@ -41,7 +41,7 @@ final class RelayClientEndToEndTests: XCTestCase {
             projectId: InputConfig.projectId,
             socketAuthenticator: socketAuthenticator
         )
-        let socket = WebSocket(url: urlFactory.create())
+        let socket = WebSocket(url: urlFactory.create(fallback: false))
         let webSocketFactory = WebSocketFactoryMock(webSocket: socket)
         let logger = ConsoleLogger(suffix: prefix, loggingLevel: .debug)
         let dispatcher = Dispatcher(

diff --git a/Sources/WalletConnectRelay/Dispatching.swift b/Sources/WalletConnectRelay/Dispatching.swift
@@ -20,7 +20,10 @@ final class Dispatcher: NSObject, Dispatching {
     private let logger: ConsoleLogging
 
     private let defaultTimeout: Int = 5
-
+    /// The property is used to determine whether relay.walletconnect.org will be used
+    /// in case relay.walletconnect.com doesn't respond for some reason (most likely due to being blocked in the user's location).
+    private var fallback = false
+
     private let socketConnectionStatusPublisherSubject = CurrentValueSubject<SocketConnectionStatus, Never>(.disconnected)
 
     var socketConnectionStatusPublisher: AnyPublisher<SocketConnectionStatus, Never> {
@@ -38,7 +41,7 @@ final class Dispatcher: NSObject, Dispatching {
         self.relayUrlFactory = relayUrlFactory
         self.logger = logger
 
-        let socket = socketFactory.create(with: relayUrlFactory.create())
+        let socket = socketFactory.create(with: relayUrlFactory.create(fallback: fallback))
         socket.request.addValue(EnvironmentInfo.userAgent, forHTTPHeaderField: "User-Agent")
         self.socket = socket
 
@@ -72,10 +75,11 @@ final class Dispatcher: NSObject, Dispatching {
             .filter { $0 == .connected }
             .setFailureType(to: NetworkError.self)
             .timeout(.seconds(defaultTimeout), scheduler: concurrentQueue, customError: { .webSocketNotConnected })
-            .sink(receiveCompletion: { result in
+            .sink(receiveCompletion: { [unowned self] result in
                 switch result {
                 case .failure(let error):
                     cancellable?.cancel()
+                    self.handleFallbackIfNeeded(error: error)
                     completion(error)
                 case .finished: break
                 }
@@ -104,7 +108,10 @@ final class Dispatcher: NSObject, Dispatching {
     func disconnect(closeCode: URLSessionWebSocketTask.CloseCode) throws {
         try socketConnectionHandler.handleDisconnect(closeCode: closeCode)
     }
+}
 
+// MARK: - Private functions
+extension Dispatcher {
     private func setUpWebSocketSession() {
         socket.onText = { [unowned self] in
             self.onMessage?($0)
@@ -118,11 +125,22 @@ final class Dispatcher: NSObject, Dispatching {
         socket.onDisconnect = { [unowned self] error in
             self.socketConnectionStatusPublisherSubject.send(.disconnected)
             if error != nil {
-                self.socket.request.url = relayUrlFactory.create()
+                self.socket.request.url = relayUrlFactory.create(fallback: fallback)
             }
             Task(priority: .high) {
                 await self.socketConnectionHandler.handleDisconnection()
             }
         }
     }
+
+    private func handleFallbackIfNeeded(error: NetworkError) {
+        if error == .webSocketNotConnected && socket.request.url?.host == NetworkConstants.defaultUrl {
+            logger.debug("[WebSocket] - Fallback to \(NetworkConstants.fallbackUrl)")
+            fallback = true
+            socket.request.url = relayUrlFactory.create(fallback: fallback)
+            Task(priority: .high) {
+                await self.socketConnectionHandler.handleDisconnection()
+            }
+        }
+    }
 }
diff --git a/Sources/WalletConnectRelay/Misc/NetworkConstants.swift b/Sources/WalletConnectRelay/Misc/NetworkConstants.swift
@@ -0,0 +1,4 @@
+enum NetworkConstants {
+    static var defaultUrl = "relay.walletconnect.com"
+    static var fallbackUrl = "relay.walletconnect.org"
+}
diff --git a/Sources/WalletConnectRelay/Misc/NetworkError.swift b/Sources/WalletConnectRelay/Misc/NetworkError.swift
@@ -1,9 +1,18 @@
 import Foundation
 
-enum NetworkError: Error {
+enum NetworkError: Error, Equatable {
     case webSocketNotConnected
     case sendMessageFailed(Error)
     case receiveMessageFailure(Error)
+
+    static func == (lhs: NetworkError, rhs: NetworkError) -> Bool {
+        switch (lhs, rhs) {
+        case (.webSocketNotConnected, .webSocketNotConnected):  return true
+        case (.sendMessageFailed, .sendMessageFailed):          return true
+        case (.receiveMessageFailure, .receiveMessageFailure):  return true
+        default:                                                return false
+        }
+    }
 }
 
 extension NetworkError: LocalizedError {

diff --git a/Sources/WalletConnectRelay/RelayURLFactory.swift b/Sources/WalletConnectRelay/RelayURLFactory.swift
@@ -4,7 +4,7 @@ struct RelayUrlFactory {
     private let relayHost: String
     private let projectId: String
     private let socketAuthenticator: ClientIdAuthenticating
-
+    
     init(
         relayHost: String,
         projectId: String,
@@ -15,10 +15,10 @@ struct RelayUrlFactory {
         self.socketAuthenticator = socketAuthenticator
     }
 
-    func create() -> URL {
+    func create(fallback: Bool) -> URL {
         var components = URLComponents()
         components.scheme = "wss"
-        components.host = relayHost
+        components.host = fallback ? NetworkConstants.fallbackUrl : relayHost
         components.queryItems = [
             URLQueryItem(name: "projectId", value: projectId)
         ]