Refactor 'if let' to 'guard let' in 'Sources'

Author: Daniel Browne

Sources/Models/PusherChannel.swift

@@ -128,9 +128,11 @@ open class PusherChannel: NSObject {
         - parameter callbackId: The unique callbackId string used to identify which callback to unbind
     */
     open func unbind(eventName: String, callbackId: String) {
-        if let eventSpecificHandlers = self.eventHandlers[eventName] {
-            self.eventHandlers[eventName] = eventSpecificHandlers.filter({ $0.id != callbackId })
+        guard let eventSpecificHandlers = self.eventHandlers[eventName] else {
+            return
         }
+
+        self.eventHandlers[eventName] = eventSpecificHandlers.filter({ $0.id != callbackId })
     }
 
     /**
@@ -155,11 +157,13 @@ open class PusherChannel: NSObject {
         - parameter event: The event received from the websocket
     */
     open func handleEvent(event: PusherEvent) {
-        if let eventHandlerArray = self.eventHandlers[event.eventName] {
-            for eventHandler in eventHandlerArray {
-                // swiftlint:disable:next force_cast
-                eventHandler.callback(event.copy() as! PusherEvent)
-            }
+        guard let eventHandlerArray = self.eventHandlers[event.eventName] else {
+            return
+        }
+
+        for eventHandler in eventHandlerArray {
+            // swiftlint:disable:next force_cast
+            eventHandler.callback(event.copy() as! PusherEvent)
         }
     }
 

Sources/Models/PusherPresenceChannel.swift

@@ -101,11 +101,13 @@ public typealias PusherUserInfoObject = [String: AnyObject]
             id = String.init(describing: memberJSON[Constants.JSONKeys.userId]!)
         }
 
-        if let index = self.members.firstIndex(where: { $0.userId == id }) {
-            let member = self.members[index]
-            self.members.remove(at: index)
-            self.onMemberRemoved?(member)
+        guard let index = self.members.firstIndex(where: { $0.userId == id }) else {
+            return
         }
+
+        let member = self.members[index]
+        self.members.remove(at: index)
+        self.onMemberRemoved?(member)
     }
 
     /**
@@ -116,10 +118,12 @@ public typealias PusherUserInfoObject = [String: AnyObject]
                                  to the channel
     */
     internal func setMyUserId(channelData: String) {
-        if let channelDataObject = parse(channelData: channelData),
-            let userId = channelDataObject[Constants.JSONKeys.userId] {
-            self.myId = String.init(describing: userId)
+        guard let channelDataObject = parse(channelData: channelData),
+            let userId = channelDataObject[Constants.JSONKeys.userId] else {
+            return
         }
+
+        self.myId = String.init(describing: userId)
     }
 
     /**
@@ -164,11 +168,11 @@ public typealias PusherUserInfoObject = [String: AnyObject]
         - returns: The connected user's PusherPresenceChannelMember object
     */
     open func me() -> PusherPresenceChannelMember? {
-        if let id = self.myId {
-            return findMember(userId: id)
-        } else {
+        guard let id = self.myId else {
             return nil
         }
+
+        return findMember(userId: id)
     }
 }
 

Sources/ObjC/ObjectiveC.swift

@@ -215,10 +215,10 @@ public extension AuthMethod {
 public extension PusherError {
     /// The error code as an NSNumber (for Objective-C compatibility).
     var codeOC: NSNumber? {
-        if let code = code {
-            return NSNumber(value: code)
-        } else {
+        guard let code = code else {
             return nil
         }
+
+        return NSNumber(value: code)
     }
 }

Sources/Services/PusherConnection.swift

@@ -160,15 +160,17 @@ import NWWebSocket
         - parameter channelName: The name of the channel
     */
     internal func unsubscribe(channelName: String) {
-        if let chan = self.channels.find(name: channelName), chan.subscribed {
-            self.sendEvent(event: Constants.Events.Pusher.unsubscribe,
-                data: [
-                    Constants.JSONKeys.channel: channelName
-                ] as [String: Any]
-            )
-
-            self.channels.remove(name: channelName)
+        guard let chan = self.channels.find(name: channelName), chan.subscribed else {
+            return
         }
+
+        self.sendEvent(event: Constants.Events.Pusher.unsubscribe,
+                       data: [
+                        Constants.JSONKeys.channel: channelName
+                       ] as [String: Any]
+        )
+
+        self.channels.remove(name: channelName)
     }
 
     /**
@@ -209,17 +211,19 @@ import NWWebSocket
         - parameter channel: The name of the channel
     */
     fileprivate func sendClientEvent(event: String, data: Any, channel: PusherChannel?) {
-        if let channel = channel {
-            if channel.type == .presence || channel.type == .private {
-                let dataString = JSONStringify([Constants.JSONKeys.event: event,
-                                                Constants.JSONKeys.data: data,
-                                                Constants.JSONKeys.channel: channel.name] as [String: Any])
-                self.delegate?.debugLog?(message: PusherLogger.debug(for: .clientEventSent,
-                                                                     context: dataString))
-                self.socket.send(string: dataString)
-            } else {
-                print("You must be subscribed to a private or presence channel to send client events")
-            }
+        guard let channel = channel else {
+            return
+        }
+
+        if channel.type == .presence || channel.type == .private {
+            let dataString = JSONStringify([Constants.JSONKeys.event: event,
+                                            Constants.JSONKeys.data: data,
+                                            Constants.JSONKeys.channel: channel.name] as [String: Any])
+            self.delegate?.debugLog?(message: PusherLogger.debug(for: .clientEventSent,
+                                                                 context: dataString))
+            self.socket.send(string: dataString)
+        } else {
+            print("You must be subscribed to a private or presence channel to send client events")
         }
     }
 
@@ -433,36 +437,39 @@ import NWWebSocket
         - parameter json: The PusherEventJSON containing successful subscription data
     */
     fileprivate func handleSubscriptionSucceededEvent(event: PusherEvent) {
-        if let channelName = event.channelName, let chan = self.channels.find(name: channelName) {
-            chan.subscribed = true
+        guard let channelName = event.channelName,
+              let chan = self.channels.find(name: channelName) else {
+            return
+        }
 
-            guard event.data != nil else {
-                self.delegate?.debugLog?(message: PusherLogger.debug(for: .subscriptionSucceededNoDataInPayload))
-                return
-            }
+        chan.subscribed = true
 
-            if PusherChannelType.isPresenceChannel(name: channelName) {
-                if let presChan = self.channels.find(name: channelName) as? PusherPresenceChannel {
-                    if let dataJSON = event.dataToJSONObject() as? [String: Any],
-                        let presenceData = dataJSON[Constants.JSONKeys.presence] as? [String: AnyObject],
-                        let presenceHash = presenceData[Constants.JSONKeys.hash] as? [String: AnyObject] {
-                        presChan.addExistingMembers(memberHash: presenceHash)
-                    }
+        guard event.data != nil else {
+            self.delegate?.debugLog?(message: PusherLogger.debug(for: .subscriptionSucceededNoDataInPayload))
+            return
+        }
+
+        if PusherChannelType.isPresenceChannel(name: channelName) {
+            if let presChan = self.channels.find(name: channelName) as? PusherPresenceChannel {
+                if let dataJSON = event.dataToJSONObject() as? [String: Any],
+                   let presenceData = dataJSON[Constants.JSONKeys.presence] as? [String: AnyObject],
+                   let presenceHash = presenceData[Constants.JSONKeys.hash] as? [String: AnyObject] {
+                    presChan.addExistingMembers(memberHash: presenceHash)
                 }
             }
+        }
 
-            let subscriptionEvent = event.copy(withEventName: Constants.Events.Pusher.subscriptionSucceeded)
-            callGlobalCallbacks(event: subscriptionEvent)
-            chan.handleEvent(event: subscriptionEvent)
+        let subscriptionEvent = event.copy(withEventName: Constants.Events.Pusher.subscriptionSucceeded)
+        callGlobalCallbacks(event: subscriptionEvent)
+        chan.handleEvent(event: subscriptionEvent)
 
-            self.delegate?.subscribedToChannel?(name: channelName)
+        self.delegate?.subscribedToChannel?(name: channelName)
 
-            chan.auth = nil
+        chan.auth = nil
 
-            while chan.unsentEvents.count > 0 {
-                if let pusherEvent = chan.unsentEvents.popLast() {
-                    chan.trigger(eventName: pusherEvent.name, data: pusherEvent.data)
-                }
+        while chan.unsentEvents.count > 0 {
+            if let pusherEvent = chan.unsentEvents.popLast() {
+                chan.trigger(eventName: pusherEvent.name, data: pusherEvent.data)
             }
         }
     }
@@ -474,21 +481,23 @@ import NWWebSocket
         - parameter event: The event to be processed
     */
     fileprivate func handleConnectionEstablishedEvent(event: PusherEvent) {
-        if let connectionData = event.dataToJSONObject() as? [String: Any],
-            let socketId = connectionData[Constants.JSONKeys.socketId] as? String {
-            self.socketId = socketId
-            self.delegate?.debugLog?(message: PusherLogger.debug(for: .connectionEstablished,
-                                                                 context: socketId))
-            self.reconnectAttempts = 0
-            self.reconnectTimer?.invalidate()
-
-            if options.activityTimeout == nil,
-                let activityTimeoutFromServer = connectionData["activity_timeout"] as? TimeInterval {
-                self.activityTimeoutInterval = activityTimeoutFromServer
-            }
+        guard let connectionData = event.dataToJSONObject() as? [String: Any],
+              let socketId = connectionData[Constants.JSONKeys.socketId] as? String else {
+            return
+        }
+
+        self.socketId = socketId
+        self.delegate?.debugLog?(message: PusherLogger.debug(for: .connectionEstablished,
+                                                             context: socketId))
+        self.reconnectAttempts = 0
+        self.reconnectTimer?.invalidate()
 
-            self.connectionEstablishedMessageReceived = true
+        if options.activityTimeout == nil,
+           let activityTimeoutFromServer = connectionData["activity_timeout"] as? TimeInterval {
+            self.activityTimeoutInterval = activityTimeoutFromServer
         }
+
+        self.connectionEstablishedMessageReceived = true
     }
 
     /**
@@ -509,13 +518,15 @@ import NWWebSocket
         - parameter event: The event to be processed
     */
     fileprivate func handleMemberAddedEvent(event: PusherEvent) {
-        if let channelName = event.channelName,
-            let chan = self.channels.find(name: channelName) as? PusherPresenceChannel {
-            if let memberJSON = event.dataToJSONObject() as? [String: Any] {
-                chan.addMember(memberJSON: memberJSON)
-            } else {
-                print("Unable to add member")
-            }
+        guard let channelName = event.channelName,
+            let chan = self.channels.find(name: channelName) as? PusherPresenceChannel else {
+            return
+        }
+
+        if let memberJSON = event.dataToJSONObject() as? [String: Any] {
+            chan.addMember(memberJSON: memberJSON)
+        } else {
+            print("Unable to add member")
         }
     }
 
@@ -525,13 +536,15 @@ import NWWebSocket
         - parameter event: The event to be processed
     */
     fileprivate func handleMemberRemovedEvent(event: PusherEvent) {
-        if let channelName = event.channelName,
-            let chan = self.channels.find(name: channelName) as? PusherPresenceChannel {
-            if let memberJSON = event.dataToJSONObject() as? [String: Any] {
-                chan.removeMember(memberJSON: memberJSON)
-            } else {
-                print("Unable to remove member")
-            }
+        guard let channelName = event.channelName,
+            let chan = self.channels.find(name: channelName) as? PusherPresenceChannel else {
+            return
+        }
+
+        if let memberJSON = event.dataToJSONObject() as? [String: Any] {
+            chan.removeMember(memberJSON: memberJSON)
+        } else {
+            print("Unable to remove member")
         }
     }
 
@@ -559,20 +572,22 @@ import NWWebSocket
             Constants.JSONKeys.channel: channelName,
             Constants.JSONKeys.data: error.data ?? ""
         ]
-        if let event = try? self.eventFactory.makeEvent(fromJSON: json, withDecryptionKey: nil) {
-            DispatchQueue.main.async {
-                // TODO: Consider removing in favour of exclusively using delegate
-                self.handleEvent(event: event)
-            }
+        guard let event = try? self.eventFactory.makeEvent(fromJSON: json, withDecryptionKey: nil) else {
+            return
+        }
 
-            if let message = error.message {
-                print(message)
-            }
-            self.delegate?.failedToSubscribeToChannel?(name: channelName,
-                                                       response: error.response,
-                                                       data: error.data,
-                                                       error: error.error)
+        DispatchQueue.main.async {
+            // TODO: Consider removing in favour of exclusively using delegate
+            self.handleEvent(event: event)
         }
+
+        if let message = error.message {
+            print(message)
+        }
+        self.delegate?.failedToSubscribeToChannel?(name: channelName,
+                                                   response: error.response,
+                                                   data: error.data,
+                                                   error: error.error)
     }
 
     /**
@@ -593,9 +608,11 @@ import NWWebSocket
             handleMemberRemovedEvent(event: event)
         default:
             callGlobalCallbacks(event: event)
-            if let channelName = event.channelName, let internalChannel = self.channels.find(name: channelName) {
-                internalChannel.handleEvent(event: event)
+            guard let channelName = event.channelName,
+               let internalChannel = self.channels.find(name: channelName) else {
+                return
             }
+            internalChannel.handleEvent(event: event)
         }
     }
 

Sources/Services/PusherEventQueue.swift

@@ -53,21 +53,25 @@ class PusherConcreteEventQueue: PusherEventQueue {
         } catch PusherEventError.invalidDecryptionKey {
             // Reload decryption key if we could not decrypt the payload due to the key
             // Only events on encrypted channels throw this error, which have a channel
-            if let channel = channel {
-                self.delegate?.eventQueue(self, reloadDecryptionKeySyncForChannel: channel)
-                do {
-                    try self.processEvent(json: json, channel: channel)
-                } catch {
-                    self.delegate?.eventQueue(self,
-                                              didFailToDecryptEventWithPayload: json,
-                                              forChannelName: channel.name)
-                }
+            guard let channel = channel else {
+                return
+            }
+
+            self.delegate?.eventQueue(self, reloadDecryptionKeySyncForChannel: channel)
+            do {
+                try self.processEvent(json: json, channel: channel)
+            } catch {
+                self.delegate?.eventQueue(self,
+                                          didFailToDecryptEventWithPayload: json,
+                                          forChannelName: channel.name)
             }
         } catch PusherEventError.invalidEncryptedData {
             // If there was a problem with the payload, e.g. nonce missing, then we cannot retry
-            if let channelName = channel?.name {
-                self.delegate?.eventQueue(self, didFailToDecryptEventWithPayload: json, forChannelName: channelName)
+            guard let channelName = channel?.name else {
+                return
             }
+
+            self.delegate?.eventQueue(self, didFailToDecryptEventWithPayload: json, forChannelName: channelName)
         } catch {
             self.delegate?.eventQueue(self, didReceiveInvalidEventWithPayload: json)
         }