Moves 'PusherChannel' encryption helpers to extension methods

- Also renames the methods for best practices and readability

Author: danielrbrowne

PusherSwift.xcodeproj/project.pbxproj

@@ -57,6 +57,7 @@
 		53AF00C525D2AE760005621D /* EventFactory.swift in Sources */ = {isa = PBXBuildFile; fileRef = 53AF00C425D2AE760005621D /* EventFactory.swift */; };
 		53AF00C925D2AEC70005621D /* EventQueue.swift in Sources */ = {isa = PBXBuildFile; fileRef = 53AF00C825D2AEC70005621D /* EventQueue.swift */; };
 		53AF00D125D2B02D0005621D /* EventQueueDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = 53AF00D025D2B02D0005621D /* EventQueueDelegate.swift */; };
+		53F08C4825ECEFFD00BDFFB3 /* PusherChannel+EncryptionHelpers.swift in Sources */ = {isa = PBXBuildFile; fileRef = 53F08C4725ECEFFD00BDFFB3 /* PusherChannel+EncryptionHelpers.swift */; };
 		736E53F5242A378B0052CC1B /* String+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 736E53F3242A35D90052CC1B /* String+Extensions.swift */; };
 		736E53F7242A45AC0052CC1B /* XCTest+Assertions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 736E53F6242A45AC0052CC1B /* XCTest+Assertions.swift */; };
 		E2498293231E612700CFBBD6 /* PusherError.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2498292231E612700CFBBD6 /* PusherError.swift */; };
@@ -134,6 +135,7 @@
 		53AF00C425D2AE760005621D /* EventFactory.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EventFactory.swift; sourceTree = "<group>"; };
 		53AF00C825D2AEC70005621D /* EventQueue.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EventQueue.swift; sourceTree = "<group>"; };
 		53AF00D025D2B02D0005621D /* EventQueueDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EventQueueDelegate.swift; sourceTree = "<group>"; };
+		53F08C4725ECEFFD00BDFFB3 /* PusherChannel+EncryptionHelpers.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "PusherChannel+EncryptionHelpers.swift"; sourceTree = "<group>"; };
 		736E53F3242A35D90052CC1B /* String+Extensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "String+Extensions.swift"; sourceTree = "<group>"; };
 		736E53F6242A45AC0052CC1B /* XCTest+Assertions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "XCTest+Assertions.swift"; sourceTree = "<group>"; };
 		73D8A22C2435F381001FDE05 /* ChannelEventFactory+DecryptionTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "ChannelEventFactory+DecryptionTests.swift"; sourceTree = "<group>"; };
@@ -277,6 +279,7 @@
 		5333ACFC24F80F5C006E8DF0 /* Extensions */ = {
 			isa = PBXGroup;
 			children = (
+				53F08C4725ECEFFD00BDFFB3 /* PusherChannel+EncryptionHelpers.swift */,
 				E2B21F0C243F5DC10049A35B /* PusherConnection+WebsocketDelegate.swift */,
 				533CA05825D42FE400043763 /* URL+Pusher.swift */,
 			);
@@ -587,6 +590,7 @@
 				3390D1E81F054D1E00E1944D /* Authorizer.swift in Sources */,
 				3389F5721CAEDDF300563F49 /* PusherChannels.swift in Sources */,
 				E2CFE43122D79CA7004187C3 /* EventParser.swift in Sources */,
+				53F08C4825ECEFFD00BDFFB3 /* PusherChannel+EncryptionHelpers.swift in Sources */,
 				53A9AFCD25CDAFD8008B1736 /* EventError.swift in Sources */,
 				3389F5761CAEDE2800563F49 /* PusherGlobalChannel.swift in Sources */,
 				E2B21F01243F5B1E0049A35B /* ChannelEventFactory.swift in Sources */,

Sources/Extensions/PusherChannel+EncryptionHelpers.swift

@@ -0,0 +1,28 @@
+import Foundation
+
+extension PusherChannel {
+
+    /// Determines whether or not a message should be decrypted, based on channel and event attributes.
+    /// - Parameters:
+    ///   - name: The name of the channel.
+    ///   - eventName: The name of the event received on the channel.
+    /// - Returns: A `Bool` indicating whether the message should be decrypted or not.
+    static func decryptsMessage(name: String?, eventName: String) -> Bool {
+        return isEncrypted(name: name) && !isSystemEvent(eventName: eventName)
+    }
+
+    /// Determines if a channel is a private encrypted or not, based on its name.
+    /// - Parameter name: The name of the channel.
+    /// - Returns: A `Bool` indicating whether the channel is encrypted or not.
+    static func isEncrypted(name: String?) -> Bool {
+        return name?.starts(with: "\(Constants.ChannelTypes.privateEncrypted)-") ?? false
+    }
+
+    /// Determines if an event is a system event or not, based on its name.
+    /// - Parameter eventName: The name of the event.
+    /// - Returns: A `Bool` indicating whether the event is a system event or not.
+    private static func isSystemEvent(eventName: String) -> Bool {
+        return eventName.starts(with: "\(Constants.EventTypes.pusher):")
+            || eventName.starts(with: "\(Constants.EventTypes.pusherInternal):")
+    }
+}

Sources/Helpers/Crypto.swift

@@ -55,22 +55,6 @@ struct Crypto {
         return decryptedString
     }
 
-    /// Determines whether or not a message should be decrypted, based on event and channel attributes.
-    /// - Parameters:
-    ///   - eventName: The name of the event.
-    ///   - channelName: The name of the channel associated with the event.
-    /// - Returns: A `Bool` indicating whether the message should be decrypted or not.
-    public static func shouldDecryptMessage(eventName: String, channelName: String?) -> Bool {
-        return isEncryptedChannel(channelName: channelName) && !isPusherSystemEvent(eventName: eventName)
-    }
-
-    /// Determines if a data sent over a channel are encrypted or not.
-    /// - Parameter channelName: The name of the channel.
-    /// - Returns: A `Bool` indicating whether the channel is encrypted or not.
-    public static func isEncryptedChannel(channelName: String?) -> Bool {
-        return channelName?.starts(with: "\(Constants.ChannelTypes.privateEncrypted)-") ?? false
-    }
-
     // MARK: - Private methods
 
     private static func encryptedData(fromData data: String) throws -> EncryptedData {
@@ -105,9 +89,4 @@ struct Crypto {
 
         return decodedDecryptionKey
     }
-
-    private static func isPusherSystemEvent(eventName: String) -> Bool {
-        return eventName.starts(with: "\(Constants.EventTypes.pusher):")
-            || eventName.starts(with: "\(Constants.EventTypes.pusherInternal):")
-    }
 }

Sources/Models/PusherChannel.swift

@@ -164,7 +164,7 @@ open class PusherChannel: NSObject {
         - parameter data:      The data to be sent as the message payload
     */
     open func trigger(eventName: String, data: Any) {
-        if Crypto.isEncryptedChannel(channelName: self.name) {
+        if PusherChannel.isEncrypted(name: self.name) {
             let context = "'\(self.name)'. Client event '\(eventName)' will not be sent"
             Logger.shared.error(for: .clientEventsNotSupported,
                                 context: context)

Sources/PusherSwift.swift

@@ -54,7 +54,7 @@ let CLIENT_NAME = "pusher-websocket-swift"
         onMemberRemoved: ((PusherPresenceChannelMember) -> Void)? = nil
     ) -> PusherChannel {
 
-        let isEncryptedChannel = Crypto.isEncryptedChannel(channelName: channelName)
+        let isEncryptedChannel = PusherChannel.isEncrypted(name: channelName)
 
         if isEncryptedChannel && auth != nil {
             Logger.shared.warning(for: .authValueOnSubscriptionNotSupported)

Sources/Services/ChannelEventFactory.swift

@@ -31,7 +31,7 @@ struct ChannelEventFactory: EventFactory {
                       decryptionKey: String?) throws -> String? {
         let data = json[Constants.JSONKeys.data] as? String
 
-        if Crypto.shouldDecryptMessage(eventName: eventName, channelName: channelName) {
+        if PusherChannel.decryptsMessage(name: channelName, eventName: eventName) {
             return try Crypto.decrypt(data: data, decryptionKey: decryptionKey)
         } else {
             return data