update readme

v16.1.1

.github/workflows/swift.yml

@@ -0,0 +1,19 @@
+name: Swift
+
+on:
+  push:
+    branches: [ "master", "development" ]
+  pull_request:
+    branches: [ "master", "development" ]
+
+jobs:
+  build:
+
+    runs-on: macos-latest
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Build
+        run: swift build -v
+      - name: Run tests
+        run: swift test -v

.gitignore

@@ -50,3 +50,5 @@ Socket.IO-Test-Server/node_modules/*
 .idea/
 docs/docsets/
 docs/undocumented.json
+
+.swiftpm

.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "self:">
+   </FileRef>
+</Workspace>

.travis.yml

@@ -1,18 +0,0 @@
-language: objective-c
-xcode_project: Socket.IO-Client-Swift.xcodeproj # path to your xcodeproj folder
-xcode_scheme: SocketIO-Mac
-osx_image: xcode12.2
-branches:
-  only:
-    - master
-    - development
-before_install:
-  # - brew update
-  # - brew outdated xctool || brew upgrade xctool
-  # - brew outdated carthage || brew upgrade carthage
-  - carthage update --platform macosx
-script:
-  - xcodebuild -project Socket.IO-Client-Swift.xcodeproj -scheme SocketIO build test -quiet
-#  - xcodebuild -project Socket.IO-Client-Swift.xcodeproj -scheme SocketIO build-for-testing -quiet
-#  - xctool -project Socket.IO-Client-Swift.xcodeproj -scheme SocketIO run-tests --parallelize
-  - swift test

CHANGELOG.md

@@ -1,3 +1,8 @@
+# v16.1.0
+
+- Remove support for iOS 11.
+- Update to Starscream 4.0.6
+
 # v16.0.0
 
 - Removed Objective-C support. It's time for you to embrace Swift.

Cartfile

@@ -1 +1 @@
-github "daltoniam/Starscream" ~> 4.0
+github "daltoniam/Starscream" ~> 4.0.8

Cartfile.resolved

@@ -1 +1 @@
-github "daltoniam/Starscream" "4.0.4"
+github "daltoniam/Starscream" "4.0.8"

Package.resolved

@@ -6,8 +6,8 @@
         "repositoryURL": "https://github.com/daltoniam/Starscream",
         "state": {
           "branch": null,
-          "revision": "df8d82047f6654d8e4b655d1b1525c64e1059d21",
+          "revision": "c6bfd1af48efcc9a9ad203665db12375ba6b145a",
-          "version": "4.0.4"
+          "version": "4.0.8"
         }
       }
     ]

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.3
+// swift-tools-version:5.4
 
 import PackageDescription
 
@@ -8,7 +8,7 @@ let package = Package(
         .library(name: "SocketIO", targets: ["SocketIO"])
     ],
     dependencies: [
-        .package(url: "https://github.com/daltoniam/Starscream", .upToNextMinor(from: "4.0.0")),
+        .package(url: "https://github.com/daltoniam/Starscream", .upToNextMajor(from: "4.0.8")),
     ],
     targets: [
         .target(name: "SocketIO", dependencies: ["Starscream"]),

README.md

@@ -18,7 +18,7 @@ socket.on("currentAmount") {data, ack in
     guard let cur = data[0] as? Double else { return }
     
     socket.emitWithAck("canUpdate", cur).timingOut(after: 0) {data in
-        if data.first as? String ?? "passed" == SocketAckValue.noAck {
+        if data.first as? String ?? "passed" == SocketAckStatus.noAck {
             // Handle ack timeout 
         }
 
@@ -32,7 +32,7 @@ socket.connect()
 ```
 
 ## Features
-- Supports socket.io 2.0+/3.0+.
+- Supports Socket.IO server 2.0+/3.0+/4.0+ (see the [compatibility table](https://nuclearace.github.io/Socket.IO-Client-Swift/Compatibility.html))
 - Supports Binary
 - Supports Polling and WebSockets
 - Supports TLS/SSL
@@ -61,7 +61,7 @@ let package = Package(
         .executable(name: "socket.io-test", targets: ["YourTargetName"])
     ],
     dependencies: [
-        .package(url: "https://github.com/socketio/socket.io-client-swift", .upToNextMinor(from: "15.0.0"))
+        .package(url: "https://github.com/socketio/socket.io-client-swift", .upToNextMinor(from: "16.1.1"))
     ],
     targets: [
         .target(name: "YourTargetName", dependencies: ["SocketIO"], path: "./Path/To/Your/Sources")
@@ -74,7 +74,7 @@ Then import `import SocketIO`.
 ### Carthage
 Add this line to your `Cartfile`:
 ```
-github "socketio/socket.io-client-swift" ~> 15.2.0
+github "socketio/socket.io-client-swift" ~> 16.1.1
 ```
 
 Run `carthage update --platform ios,macosx`.
@@ -88,7 +88,7 @@ Create `Podfile` and add `pod 'Socket.IO-Client-Swift'`:
 use_frameworks!
 
 target 'YourApp' do
-    pod 'Socket.IO-Client-Swift', '~> 15.2.0'
+    pod 'Socket.IO-Client-Swift', '~> 16.1.1'
 end
 ```
 

Socket.IO-Client-Swift.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
   s.name         = "Socket.IO-Client-Swift"
   s.module_name  = "SocketIO"
-  s.version      = "16.0.0"
+  s.version      = "16.1.1"
   s.summary      = "Socket.IO-client for iOS and OS X"
   s.description  = <<-DESC
                    Socket.IO-client for iOS and OS X.
@@ -11,21 +11,21 @@ Pod::Spec.new do |s|
   s.homepage     = "https://github.com/socketio/socket.io-client-swift"
   s.license      = { :type => 'MIT' }
   s.author       = { "Erik" => "nuclear.ace@gmail.com" }
-  s.ios.deployment_target = '10.0'
+  s.ios.deployment_target = '12.0'
   s.osx.deployment_target = '10.13'
-  s.tvos.deployment_target = '10.0'
+  s.tvos.deployment_target = '12.0'
   s.watchos.deployment_target = '5.0'
   s.requires_arc = true
   s.source = {
     :git => "https://github.com/socketio/socket.io-client-swift.git",
-    :tag => 'v16.0.0',
+    :tag => 'v16.1.1',
     :submodules => true
   }
 
   s.swift_version = "5"
   s.pod_target_xcconfig = {
-      'SWIFT_VERSION' => '5.0'
+      'SWIFT_VERSION' => '5.4'
   }
   s.source_files  = "Source/SocketIO/**/*.swift", "Source/SocketIO/*.swift"
-  s.dependency "Starscream", "~> 4.0"
+  s.dependency "Starscream", "~> 4.0.8"
 end

Socket.IO-Client-Swift.xcodeproj/project.pbxproj

@@ -3,7 +3,7 @@
 	archiveVersion = 1;
 	classes = {
 	};
-	objectVersion = 46;
+	objectVersion = 54;
 	objects = {
 
 /* Begin PBXBuildFile section */
@@ -19,9 +19,9 @@
 		1C686BE71F869AFD007D8627 /* SocketParserTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1C686BD71F869AF1007D8627 /* SocketParserTest.swift */; };
 		1C686BE81F869AFD007D8627 /* SocketNamespacePacketTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1C686BD81F869AF1007D8627 /* SocketNamespacePacketTest.swift */; };
 		572EF2431B51F18A00EEBB58 /* SocketIO.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 572EF2381B51F18A00EEBB58 /* SocketIO.framework */; };
+		579C7D4C2731B487009F8A2F /* Starscream.xcframework in Frameworks */ = {isa = PBXBuildFile; fileRef = 579C7D4B2731B487009F8A2F /* Starscream.xcframework */; };
 		6CA08A981D615C0B0061FD2A /* Security.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 6CA08A971D615C0B0061FD2A /* Security.framework */; };
 		74BF53581F894326004972D8 /* SocketIO.h in Headers */ = {isa = PBXBuildFile; fileRef = 572EF23C1B51F18A00EEBB58 /* SocketIO.h */; settings = {ATTRIBUTES = (Public, ); }; };
-		74D0F5961F8053950037C4DC /* Starscream.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 9432E00B1F77F883006AF628 /* Starscream.framework */; };
 		74DA21741F09440F009C19EE /* libz.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 74DA21731F09440F009C19EE /* libz.tbd */; };
 		74DA217C1F09457B009C19EE /* libz.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 74DA21731F09440F009C19EE /* libz.tbd */; };
 		DD52B048C71D724ABBD18C71 /* SocketTypes.swift in Sources */ = {isa = PBXBuildFile; fileRef = DD52BDC9E66AADA2CC5E8246 /* SocketTypes.swift */; };
@@ -75,18 +75,15 @@
 		572EF23B1B51F18A00EEBB58 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		572EF23C1B51F18A00EEBB58 /* SocketIO.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = SocketIO.h; sourceTree = "<group>"; };
 		572EF2421B51F18A00EEBB58 /* SocketIO-Tests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = "SocketIO-Tests.xctest"; sourceTree = BUILT_PRODUCTS_DIR; };
+		579C7D4B2731B487009F8A2F /* Starscream.xcframework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.xcframework; name = Starscream.xcframework; path = Carthage/Build/Starscream.xcframework; sourceTree = "<group>"; };
 		6CA08A951D615C040061FD2A /* Security.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Security.framework; path = Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS9.3.sdk/System/Library/Frameworks/Security.framework; sourceTree = DEVELOPER_DIR; };
 		6CA08A971D615C0B0061FD2A /* Security.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Security.framework; path = System/Library/Frameworks/Security.framework; sourceTree = SDKROOT; };
 		6CA08A991D615C140061FD2A /* Security.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Security.framework; path = Platforms/AppleTVOS.platform/Developer/SDKs/AppleTVOS9.2.sdk/System/Library/Frameworks/Security.framework; sourceTree = DEVELOPER_DIR; };
-		749FA19F1F8112E7002FBB30 /* Starscream.framework.dSYM */ = {isa = PBXFileReference; lastKnownFileType = wrapper.dsym; name = Starscream.framework.dSYM; path = Carthage/Build/Mac/Starscream.framework.dSYM; sourceTree = "<group>"; };
 		749FA1A11F811408002FBB30 /* Foundation.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Foundation.framework; path = System/Library/Frameworks/Foundation.framework; sourceTree = SDKROOT; };
 		74D0F58D1F804FED0037C4DC /* libz.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libz.tbd; path = Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.0.sdk/usr/lib/libz.tbd; sourceTree = DEVELOPER_DIR; };
 		74DA21731F09440F009C19EE /* libz.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libz.tbd; path = usr/lib/libz.tbd; sourceTree = SDKROOT; };
 		74DA217D1F0945E9009C19EE /* libcommonCrypto.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libcommonCrypto.tbd; path = usr/lib/system/libcommonCrypto.tbd; sourceTree = SDKROOT; };
 		9432E0061F77F7CA006AF628 /* SSLSecurity.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SSLSecurity.swift; sourceTree = "<group>"; };
-		9432E0091F77F87D006AF628 /* Starscream.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Starscream.framework; path = Carthage/Build/iOS/Starscream.framework; sourceTree = "<group>"; };
-		9432E00B1F77F883006AF628 /* Starscream.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Starscream.framework; path = Carthage/Build/Mac/Starscream.framework; sourceTree = "<group>"; };
-		9432E00D1F77F889006AF628 /* Starscream.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Starscream.framework; path = Carthage/Build/tvOS/Starscream.framework; sourceTree = "<group>"; };
 		DD52B078DB0A3C3D1BB507CD /* SocketIOClientOption.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SocketIOClientOption.swift; sourceTree = "<group>"; };
 		DD52B09F7984E730513AB7E5 /* SocketAckManager.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SocketAckManager.swift; sourceTree = "<group>"; };
 		DD52B1D9BC4AE46D38D827DE /* SocketIOStatus.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SocketIOStatus.swift; sourceTree = "<group>"; };
@@ -120,8 +117,8 @@
 			buildActionMask = 2147483647;
 			files = (
 				74DA21741F09440F009C19EE /* libz.tbd in Frameworks */,
+				579C7D4C2731B487009F8A2F /* Starscream.xcframework in Frameworks */,
 				6CA08A981D615C0B0061FD2A /* Security.framework in Frameworks */,
-				74D0F5961F8053950037C4DC /* Starscream.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -231,11 +228,8 @@
 			isa = PBXGroup;
 			children = (
 				749FA1A11F811408002FBB30 /* Foundation.framework */,
-				749FA19F1F8112E7002FBB30 /* Starscream.framework.dSYM */,
+				579C7D4B2731B487009F8A2F /* Starscream.xcframework */,
 				74D0F58D1F804FED0037C4DC /* libz.tbd */,
-				9432E0091F77F87D006AF628 /* Starscream.framework */,
-				9432E00B1F77F883006AF628 /* Starscream.framework */,
-				9432E00D1F77F889006AF628 /* Starscream.framework */,
 				74DA217D1F0945E9009C19EE /* libcommonCrypto.tbd */,
 				74DA21731F09440F009C19EE /* libz.tbd */,
 				6CA08A9E1D615C340061FD2A /* tvOS */,
@@ -350,9 +344,9 @@
 			isa = PBXNativeTarget;
 			buildConfigurationList = 572EF24B1B51F18A00EEBB58 /* Build configuration list for PBXNativeTarget "SocketIO" */;
 			buildPhases = (
+				572EF2351B51F18A00EEBB58 /* Headers */,
 				572EF2331B51F18A00EEBB58 /* Sources */,
 				572EF2341B51F18A00EEBB58 /* Frameworks */,
-				572EF2351B51F18A00EEBB58 /* Headers */,
 				572EF2361B51F18A00EEBB58 /* Resources */,
 			);
 			buildRules = (
@@ -517,7 +511,6 @@
 		572EF2121B51F12F00EEBB58 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				BITCODE_GENERATION_MODE = bitcode;
 				CLANG_ANALYZER_LOCALIZABILITY_NONLOCALIZED = YES;
 				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
@@ -537,37 +530,11 @@
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
 				CODE_SIGN_IDENTITY = "Mac Developer";
-				ENABLE_BITCODE = YES;
-				"ENABLE_BITCODE[sdk=macosx*]" = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				ENABLE_TESTABILITY = YES;
-				"FRAMEWORK_SEARCH_PATHS[sdk=appletvos*]" = (
+				FRAMEWORK_SEARCH_PATHS = (
-					"$(inherited)",
-					"$(PROJECT_DIR)/Carthage/Build/tvOS",
-				);
-				"FRAMEWORK_SEARCH_PATHS[sdk=appletvsimulator*]" = (
-					"$(inherited)",
-					"$(PROJECT_DIR)/Carthage/Build/tvOS",
-				);
-				"FRAMEWORK_SEARCH_PATHS[sdk=iphoneos*]" = (
-					"$(inherited)",
-					"$(PROJECT_DIR)/Carthage/Build/iOS",
-				);
-				"FRAMEWORK_SEARCH_PATHS[sdk=iphonesimulator*]" = (
-					"$(inherited)",
-					"$(PROJECT_DIR)/Carthage/Build/iOS",
-				);
-				"FRAMEWORK_SEARCH_PATHS[sdk=macosx*]" = (
-					"$(inherited)",
-					"$(PROJECT_DIR)/Carthage/Build/Mac",
-				);
-				"FRAMEWORK_SEARCH_PATHS[sdk=watchos*]" = (
-					"$(PROJECT_DIR)/Carthage/Build/watchOS",
-					"$(inherited)",
-				);
-				"FRAMEWORK_SEARCH_PATHS[sdk=watchsimulator*]" = (
-					"$(PROJECT_DIR)/Carthage/Build/watchOS",
 					"$(inherited)",
+					"$(PROJECT_DIR)/Carthage/Build/",
 				);
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_OPTIMIZATION_LEVEL = 0;
@@ -581,7 +548,7 @@
 				MACOSX_DEPLOYMENT_TARGET = 10.14;
 				ONLY_ACTIVE_ARCH = YES;
 				PRODUCT_NAME = SocketIO;
-				SUPPORTED_PLATFORMS = "macosx appletvsimulator appletvos iphonesimulator iphoneos watchos watchsimulator";
+				SUPPORTED_PLATFORMS = "macosx appletvsimulator appletvos iphonesimulator iphoneos watchos watchsimulator xrsimulator xros";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
 				SWIFT_VERSION = 5.0;
 				TVOS_DEPLOYMENT_TARGET = 10.0;
@@ -593,7 +560,6 @@
 		572EF2131B51F12F00EEBB58 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				BITCODE_GENERATION_MODE = bitcode;
 				CLANG_ANALYZER_LOCALIZABILITY_NONLOCALIZED = YES;
 				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
@@ -613,36 +579,10 @@
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
 				CODE_SIGN_IDENTITY = "Mac Developer";
-				ENABLE_BITCODE = YES;
-				"ENABLE_BITCODE[sdk=macosx*]" = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
-				"FRAMEWORK_SEARCH_PATHS[sdk=appletvos*]" = (
+				FRAMEWORK_SEARCH_PATHS = (
-					"$(inherited)",
-					"$(PROJECT_DIR)/Carthage/Build/tvOS",
-				);
-				"FRAMEWORK_SEARCH_PATHS[sdk=appletvsimulator*]" = (
-					"$(inherited)",
-					"$(PROJECT_DIR)/Carthage/Build/tvOS",
-				);
-				"FRAMEWORK_SEARCH_PATHS[sdk=iphoneos*]" = (
-					"$(inherited)",
-					"$(PROJECT_DIR)/Carthage/Build/iOS",
-				);
-				"FRAMEWORK_SEARCH_PATHS[sdk=iphonesimulator*]" = (
-					"$(inherited)",
-					"$(PROJECT_DIR)/Carthage/Build/iOS",
-				);
-				"FRAMEWORK_SEARCH_PATHS[sdk=macosx*]" = (
-					"$(inherited)",
-					"$(PROJECT_DIR)/Carthage/Build/Mac",
-				);
-				"FRAMEWORK_SEARCH_PATHS[sdk=watchos*]" = (
-					"$(PROJECT_DIR)/Carthage/Build/watchOS",
-					"$(inherited)",
-				);
-				"FRAMEWORK_SEARCH_PATHS[sdk=watchsimulator*]" = (
-					"$(PROJECT_DIR)/Carthage/Build/watchOS",
 					"$(inherited)",
+					"$(PROJECT_DIR)/Carthage/Build/",
 				);
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
@@ -654,8 +594,9 @@
 				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
 				MACOSX_DEPLOYMENT_TARGET = 10.14;
 				PRODUCT_NAME = SocketIO;
-				SUPPORTED_PLATFORMS = "macosx appletvsimulator appletvos iphonesimulator iphoneos watchos watchsimulator";
+				SUPPORTED_PLATFORMS = "macosx appletvsimulator appletvos iphonesimulator iphoneos watchos watchsimulator xrsimulator xros";
-				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
+				SWIFT_COMPILATION_MODE = wholemodule;
+				SWIFT_OPTIMIZATION_LEVEL = "-O";
 				SWIFT_VERSION = 5.0;
 				TVOS_DEPLOYMENT_TARGET = 10.0;
 				VALID_ARCHS = "i386 x86_64 armv7 armv7s arm64 armv7k";
@@ -666,6 +607,7 @@
 		572EF24C1B51F18A00EEBB58 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				ALLOW_TARGET_PLATFORM_SPECIALIZATION = YES;
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				APPLICATION_EXTENSION_API_ONLY = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++0x";
@@ -690,8 +632,6 @@
 				DYLIB_COMPATIBILITY_VERSION = 1;
 				DYLIB_CURRENT_VERSION = 1;
 				DYLIB_INSTALL_NAME_BASE = "@rpath";
-				ENABLE_BITCODE = YES;
-				"ENABLE_BITCODE[sdk=macosx*]" = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				ENABLE_TESTABILITY = YES;
 				FRAMEWORK_SEARCH_PATHS = "$(inherited)";
@@ -712,8 +652,17 @@
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				INFOPLIST_FILE = SocketIO/Info.plist;
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
-				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
-				"LD_RUNPATH_SEARCH_PATHS[sdk=macosx*]" = "$(inherited) @executable_path/../Frameworks @loader_path/../Frameworks";
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/Frameworks",
+					"@loader_path/Frameworks",
+				);
+				"LD_RUNPATH_SEARCH_PATHS[sdk=macosx*]" = (
+					"$(inherited)",
+					"@executable_path/../Frameworks",
+					"@loader_path/../Frameworks",
+				);
 				LIBRARY_SEARCH_PATHS = "$(inherited)";
 				MACOSX_DEPLOYMENT_TARGET = 10.10;
 				MTL_ENABLE_DEBUG_INFO = YES;
@@ -722,12 +671,15 @@
 				SDKROOT = macosx;
 				SKIP_INSTALL = YES;
 				SUPPORTED_PLATFORMS = "$(inherited)";
+				SUPPORTS_MACCATALYST = YES;
+				SUPPORTS_MAC_DESIGNED_FOR_IPHONE_IPAD = NO;
+				SUPPORTS_XR_DESIGNED_FOR_IPHONE_IPAD = NO;
 				SWIFT_INCLUDE_PATHS = "";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
 				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
 				SWIFT_VERSION = 5.0;
-				TARGETED_DEVICE_FAMILY = "1,2,3,4";
+				TARGETED_DEVICE_FAMILY = "1,2,3,4,7";
-				TVOS_DEPLOYMENT_TARGET = 10.0;
+				TVOS_DEPLOYMENT_TARGET = 12.0;
 				VALID_ARCHS = "$(inherited)";
 				VERSIONING_SYSTEM = "apple-generic";
 				VERSION_INFO_PREFIX = "";
@@ -737,6 +689,7 @@
 		572EF24D1B51F18A00EEBB58 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				ALLOW_TARGET_PLATFORM_SPECIALIZATION = YES;
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				APPLICATION_EXTENSION_API_ONLY = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++0x";
@@ -761,8 +714,6 @@
 				DYLIB_COMPATIBILITY_VERSION = 1;
 				DYLIB_CURRENT_VERSION = 1;
 				DYLIB_INSTALL_NAME_BASE = "@rpath";
-				ENABLE_BITCODE = YES;
-				"ENABLE_BITCODE[sdk=macosx*]" = NO;
 				ENABLE_NS_ASSERTIONS = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				ENABLE_TESTABILITY = YES;
@@ -778,8 +729,17 @@
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				INFOPLIST_FILE = SocketIO/Info.plist;
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
-				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
-				"LD_RUNPATH_SEARCH_PATHS[sdk=macosx*]" = "$(inherited) @executable_path/../Frameworks @loader_path/../Frameworks";
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/Frameworks",
+					"@loader_path/Frameworks",
+				);
+				"LD_RUNPATH_SEARCH_PATHS[sdk=macosx*]" = (
+					"$(inherited)",
+					"@executable_path/../Frameworks",
+					"@loader_path/../Frameworks",
+				);
 				LIBRARY_SEARCH_PATHS = "$(inherited)";
 				MACOSX_DEPLOYMENT_TARGET = 10.10;
 				MTL_ENABLE_DEBUG_INFO = NO;
@@ -787,11 +747,14 @@
 				SDKROOT = macosx;
 				SKIP_INSTALL = YES;
 				SUPPORTED_PLATFORMS = "$(inherited)";
+				SUPPORTS_MACCATALYST = YES;
+				SUPPORTS_MAC_DESIGNED_FOR_IPHONE_IPAD = NO;
+				SUPPORTS_XR_DESIGNED_FOR_IPHONE_IPAD = NO;
 				SWIFT_INCLUDE_PATHS = "";
 				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
 				SWIFT_VERSION = 5.0;
-				TARGETED_DEVICE_FAMILY = "1,2,3,4";
+				TARGETED_DEVICE_FAMILY = "1,2,3,4,7";
-				TVOS_DEPLOYMENT_TARGET = 10.0;
+				TVOS_DEPLOYMENT_TARGET = 12.0;
 				VALID_ARCHS = "$(inherited)";
 				VERSIONING_SYSTEM = "apple-generic";
 				VERSION_INFO_PREFIX = "";
@@ -819,7 +782,6 @@
 				COMBINE_HIDPI_IMAGES = YES;
 				COPY_PHASE_STRIP = NO;
 				DEBUG_INFORMATION_FORMAT = dwarf;
-				ENABLE_BITCODE = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				FRAMEWORK_SEARCH_PATHS = (
 					"$(DEVELOPER_FRAMEWORKS_DIR)",
@@ -862,10 +824,17 @@
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				INFOPLIST_FILE = SocketIO/Info.plist;
-				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
+				LD_RUNPATH_SEARCH_PATHS = (
-				"LD_RUNPATH_SEARCH_PATHS[sdk=macosx*]" = "@executable_path/../Frameworks @loader_path/../Frameworks";
+					"$(inherited)",
+					"@executable_path/Frameworks",
+					"@loader_path/Frameworks",
+				);
+				"LD_RUNPATH_SEARCH_PATHS[sdk=macosx*]" = (
+					"@executable_path/../Frameworks",
+					"@loader_path/../Frameworks",
+				);
 				LIBRARY_SEARCH_PATHS = "$(inherited)";
-				MACOSX_DEPLOYMENT_TARGET = 10.10;
+				MACOSX_DEPLOYMENT_TARGET = 10.13;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				PRODUCT_BUNDLE_IDENTIFIER = "io.socket.$(PRODUCT_NAME:rfc1034identifier)";
@@ -875,7 +844,7 @@
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
 				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
 				SWIFT_VERSION = 5.0;
-				TVOS_DEPLOYMENT_TARGET = 10.0;
+				TVOS_DEPLOYMENT_TARGET = 12.0;
 				VALID_ARCHS = "$(inherited)";
 			};
 			name = Debug;
@@ -901,7 +870,6 @@
 				COMBINE_HIDPI_IMAGES = YES;
 				COPY_PHASE_STRIP = NO;
 				DEBUG_INFORMATION_FORMAT = "dwarf-with-dsym";
-				ENABLE_BITCODE = NO;
 				ENABLE_NS_ASSERTIONS = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				FRAMEWORK_SEARCH_PATHS = (
@@ -938,10 +906,17 @@
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				INFOPLIST_FILE = SocketIO/Info.plist;
-				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
+				LD_RUNPATH_SEARCH_PATHS = (
-				"LD_RUNPATH_SEARCH_PATHS[sdk=macosx*]" = "@executable_path/../Frameworks @loader_path/../Frameworks";
+					"$(inherited)",
+					"@executable_path/Frameworks",
+					"@loader_path/Frameworks",
+				);
+				"LD_RUNPATH_SEARCH_PATHS[sdk=macosx*]" = (
+					"@executable_path/../Frameworks",
+					"@loader_path/../Frameworks",
+				);
 				LIBRARY_SEARCH_PATHS = "$(inherited)";
-				MACOSX_DEPLOYMENT_TARGET = 10.10;
+				MACOSX_DEPLOYMENT_TARGET = 10.13;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				PRODUCT_BUNDLE_IDENTIFIER = "io.socket.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
@@ -949,7 +924,7 @@
 				SUPPORTED_PLATFORMS = "$(inherited)";
 				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
 				SWIFT_VERSION = 5.0;
-				TVOS_DEPLOYMENT_TARGET = 10.0;
+				TVOS_DEPLOYMENT_TARGET = 12.0;
 				VALID_ARCHS = "$(inherited)";
 			};
 			name = Release;

Source/SocketIO/Ack/SocketAckEmitter.swift

@@ -28,7 +28,7 @@ import Foundation
 /// A class that represents a waiting ack call.
 ///
 /// **NOTE**: You should not store this beyond the life of the event handler.
-public final class SocketAckEmitter : NSObject {
+public final class SocketAckEmitter: NSObject {
     private unowned let socket: SocketIOClient
     private let ackNum: Int
 
@@ -101,7 +101,7 @@ public final class SocketAckEmitter : NSObject {
 ///     ...
 /// }
 /// ```
-public final class OnAckCallback : NSObject {
+public final class OnAckCallback: NSObject {
     private let ackNumber: Int
     private let binary: Bool
     private let items: [Any]

Source/SocketIO/Client/SocketIOClient.swift

@@ -150,7 +150,8 @@ open class SocketIOClient: NSObject, SocketIOClientSpec {
 
         manager.handleQueue.asyncAfter(deadline: DispatchTime.now() + timeoutAfter) {[weak self] in
             guard let this = self, this.status == .connecting || this.status == .notConnected else { return }
-
+            DefaultSocketLogger.Logger.log("Timeout: Socket not connected, so setting to disconnected", type: this.logType)
+            
             this.status = .disconnected
             this.leaveNamespace()
 
@@ -212,6 +213,19 @@ open class SocketIOClient: NSObject, SocketIOClientSpec {
     /// - parameter items: The items to send with this event. May be left out.
     /// - parameter completion: Callback called on transport write completion.
     open func emit(_ event: String, _ items: SocketData..., completion: (() -> ())? = nil)  {
+        emit(event, with: items, completion: completion)
+    }
+    
+    /// Send an event to the server, with optional data items and optional write completion handler.
+    ///
+    /// If an error occurs trying to transform `items` into their socket representation, a `SocketClientEvent.error`
+    /// will be emitted. The structure of the error data is `[eventName, items, theError]`
+    ///
+    /// - parameter event: The event to send.
+    /// - parameter items: The items to send with this event. May be left out.
+    /// - parameter completion: Callback called on transport write completion.
+    open func emit(_ event: String, with items: [SocketData], completion: (() -> ())?) {
+        
         do {
             emit([event] + (try items.map({ try $0.socketRepresentation() })), completion: completion)
         } catch {
@@ -242,6 +256,30 @@ open class SocketIOClient: NSObject, SocketIOClientSpec {
     /// - parameter items: The items to send with this event. May be left out.
     /// - returns: An `OnAckCallback`. You must call the `timingOut(after:)` method before the event will be sent.
     open func emitWithAck(_ event: String, _ items: SocketData...) -> OnAckCallback {
+        emitWithAck(event, with: items)
+    }
+    
+    /// Sends a message to the server, requesting an ack.
+    ///
+    /// **NOTE**: It is up to the server send an ack back, just calling this method does not mean the server will ack.
+    /// Check that your server's api will ack the event being sent.
+    ///
+    /// If an error occurs trying to transform `items` into their socket representation, a `SocketClientEvent.error`
+    /// will be emitted. The structure of the error data is `[eventName, items, theError]`
+    ///
+    /// Example:
+    ///
+    /// ```swift
+    /// socket.emitWithAck("myEvent", 1).timingOut(after: 1) {data in
+    ///     ...
+    /// }
+    /// ```
+    ///
+    /// - parameter event: The event to send.
+    /// - parameter items: The items to send with this event. May be left out.
+    /// - returns: An `OnAckCallback`. You must call the `timingOut(after:)` method before the event will be sent.
+    open func emitWithAck(_ event: String, with items: [SocketData]) -> OnAckCallback {
+        
         do {
             return createOnAck([event] + (try items.map({ try $0.socketRepresentation() })))
         } catch {

Source/SocketIO/Client/SocketIOClientOption.swift

@@ -108,6 +108,9 @@ public enum SocketIOClientOption : ClientOption {
     /// Sets an NSURLSessionDelegate for the underlying engine. Useful if you need to handle self-signed certs.
     case sessionDelegate(URLSessionDelegate)
 
+    /// If passed `false`, the WebSocket stream will be configured with the useCustomEngine `false`.
+    case useCustomEngine(Bool)
+
     /// The version of socket.io being used. This should match the server version. Default is 3.
     case version(SocketIOVersion)
 
@@ -160,6 +163,8 @@ public enum SocketIOClientOption : ClientOption {
             description = "sessionDelegate"
         case .enableSOCKSProxy:
             description = "enableSOCKSProxy"
+        case .useCustomEngine:
+            description = "customEngine"
         case .version:
             description = "version"
         }
@@ -213,6 +218,8 @@ public enum SocketIOClientOption : ClientOption {
             value = delegate
         case let .enableSOCKSProxy(enable):
             value = enable
+        case let .useCustomEngine(enable):
+            value = enable
         case let.version(versionNum):
             value = versionNum
         }

Source/SocketIO/Client/SocketIOClientSpec.swift

@@ -107,6 +107,16 @@ public protocol SocketIOClientSpec : AnyObject {
     /// - parameter items: The items to send with this event. May be left out.
     /// - parameter completion: Callback called on transport write completion.
     func emit(_ event: String, _ items: SocketData..., completion: (() -> ())?)
+    
+    /// Send an event to the server, with optional data items and optional write completion handler.
+    ///
+    /// If an error occurs trying to transform `items` into their socket representation, a `SocketClientEvent.error`
+    /// will be emitted. The structure of the error data is `[eventName, items, theError]`
+    ///
+    /// - parameter event: The event to send.
+    /// - parameter items: The items to send with this event. May be left out.
+    /// - parameter completion: Callback called on transport write completion.
+    func emit(_ event: String, with items: [SocketData], completion: (() -> ())?)
 
     /// Call when you wish to tell the server that you've received the event for `ack`.
     ///
@@ -134,6 +144,27 @@ public protocol SocketIOClientSpec : AnyObject {
     /// - parameter items: The items to send with this event. May be left out.
     /// - returns: An `OnAckCallback`. You must call the `timingOut(after:)` method before the event will be sent.
     func emitWithAck(_ event: String, _ items: SocketData...) -> OnAckCallback
+    
+    /// Sends a message to the server, requesting an ack.
+    ///
+    /// **NOTE**: It is up to the server send an ack back, just calling this method does not mean the server will ack.
+    /// Check that your server's api will ack the event being sent.
+    ///
+    /// If an error occurs trying to transform `items` into their socket representation, a `SocketClientEvent.error`
+    /// will be emitted. The structure of the error data is `[eventName, items, theError]`
+    ///
+    /// Example:
+    ///
+    /// ```swift
+    /// socket.emitWithAck("myEvent", 1).timingOut(after: 1) {data in
+    ///     ...
+    /// }
+    /// ```
+    ///
+    /// - parameter event: The event to send.
+    /// - parameter items: The items to send with this event. May be left out.
+    /// - returns: An `OnAckCallback`. You must call the `timingOut(after:)` method before the event will be sent.
+    func emitWithAck(_ event: String, with items: [SocketData]) -> OnAckCallback
 
     /// Called when socket.io has acked one of our emits. Causes the corresponding ack callback to be called.
     ///

Source/SocketIO/Engine/SocketEngine.swift

@@ -28,8 +28,10 @@ import Starscream
 
 /// The class that handles the engine.io protocol and transports.
 /// See `SocketEnginePollable` and `SocketEngineWebsocket` for transport specific methods.
-open class SocketEngine:
+open class SocketEngine: NSObject, WebSocketDelegate, URLSessionDelegate,
-        NSObject, WebSocketDelegate, URLSessionDelegate, SocketEnginePollable, SocketEngineWebsocket, ConfigSettable {
+                         SocketEnginePollable, SocketEngineWebsocket, ConfigSettable {
+  
+  
     // MARK: Properties
 
     private static let logType = "SocketEngine"
@@ -111,6 +113,9 @@ open class SocketEngine:
     /// The url for WebSockets.
     public private(set) var urlWebSocket = URL(string: "http://localhost/")!
 
+    /// When `false`, the WebSocket `stream` will be configured with the useCustomEngine `false`.
+    public private(set) var useCustomEngine = true
+
     /// The version of engine.io being used. Default is three.
     public private(set) var version: SocketIOVersion = .three
 
@@ -307,7 +312,7 @@ open class SocketEngine:
             includingCookies: session?.configuration.httpCookieStorage?.cookies(for: urlPollingWithSid)
         )
 
-        ws = WebSocket(request: req, certPinner: certPinner, compressionHandler: compress ? WSCompression() : nil)
+        ws = WebSocket(request: req, certPinner: certPinner, compressionHandler: compress ? WSCompression() : nil, useCustomEngine: useCustomEngine)
         ws?.callbackQueue = engineQueue
         ws?.delegate = self
 
@@ -624,6 +629,8 @@ open class SocketEngine:
                 self.compress = true
             case .enableSOCKSProxy:
                 self.enableSOCKSProxy = true
+            case let .useCustomEngine(enable):
+                self.useCustomEngine = enable
             case let .version(num):
                 version = num
             default:
@@ -742,16 +749,22 @@ extension SocketEngine {
     /// - Parameters:
     ///   - event: WS Event
     ///   - _:
-    public func didReceive(event: WebSocketEvent, client _: WebSocket) {
+    public func didReceive(event: Starscream.WebSocketEvent, client: Starscream.WebSocketClient) {
         switch event {
         case let .connected(headers):
             wsConnected = true
-            client?.engineDidWebsocketUpgrade(headers: headers)
+            self.client?.engineDidWebsocketUpgrade(headers: headers)
             websocketDidConnect()
         case .cancelled:
             wsConnected = false
             websocketDidDisconnect(error: EngineError.canceled)
-        case let .disconnected(reason, code):
+        case .disconnected(_, _):
+            wsConnected = false
+            websocketDidDisconnect(error: nil)
+        case .viabilityChanged(false):
+            wsConnected = false
+            websocketDidDisconnect(error: nil)
+        case .peerClosed:
             wsConnected = false
             websocketDidDisconnect(error: nil)
         case let .text(msg):

Source/SocketIO/Engine/SocketEngineSpec.swift

@@ -27,7 +27,7 @@ import Foundation
 import Starscream
 
 /// Specifies a SocketEngine.
-public protocol SocketEngineSpec: class {
+public protocol SocketEngineSpec: AnyObject {
     // MARK: Properties
 
     /// The client for this engine.

Source/SocketIO/Manager/SocketManager.swift

@@ -132,7 +132,7 @@ open class SocketManager: NSObject, SocketManagerSpec, SocketParsable, SocketDat
     private(set) var reconnectAttempts = -1
 
     private var _config: SocketIOClientConfiguration
-    private var currentReconnectAttempt = 0
+    internal var currentReconnectAttempt = 0
     private var reconnecting = false
 
     // MARK: Initializers
@@ -186,9 +186,8 @@ open class SocketManager: NSObject, SocketManagerSpec, SocketParsable, SocketDat
     ///
     /// Override if you wish to attach a custom `SocketEngineSpec`.
     open func connect() {
-        guard !status.active else {
+        if status == .connected || (status == .connecting && currentReconnectAttempt == 0) {
             DefaultSocketLogger.Logger.log("Tried connecting an already active socket", type: SocketManager.logType)
-
             return
         }
 

Source/SocketIO/Manager/SocketManagerSpec.swift

@@ -45,7 +45,7 @@ import Foundation
 /// To disconnect a socket and remove it from the manager, either call `SocketIOClient.disconnect()` on the socket,
 /// or call one of the `disconnectSocket` methods on this class.
 ///
-public protocol SocketManagerSpec : AnyObject, SocketEngineClient {
+public protocol SocketManagerSpec : SocketEngineClient {
     // MARK: Properties
 
     /// Returns the socket associated with the default namespace ("/").

Source/SocketIO/Util/SocketExtensions.swift

@@ -87,7 +87,9 @@ extension Dictionary where Key == String, Value == Any {
             return compress ? .compress : nil
         case let ("enableSOCKSProxy", enable as Bool):
             return .enableSOCKSProxy(enable)
-        default:
+        case let ("version", version as Int):
+            return .version(SocketIOVersion(rawValue: version) ?? .three)
+        case _:
             return nil
         }
     }

Tests/TestSocketIO/SocketAckManagerTest.swift

@@ -28,7 +28,6 @@ class SocketAckManagerTest : XCTestCase {
 
     func testManagerTimeoutAck() {
         let callbackExpection = expectation(description: "Manager should timeout ack with noAck status")
-        let itemsArray = ["Hi", "ho"]
 
         func callback(_ items: [Any]) {
             XCTAssertEqual(items.count, 1, "Timed out ack should have one value")

Tests/TestSocketIO/SocketMangerTest.swift

@@ -60,6 +60,44 @@ class SocketMangerTest : XCTestCase {
         waitForExpectations(timeout: 0.3)
     }
 
+    func testManagerDoesNotCallConnectWhenConnectingWithLessThanOneReconnect() {
+        setUpSockets()
+        
+        let expect = expectation(description: "The manager should not call connect on the engine")
+        expect.isInverted = true
+        
+        let engine = TestEngine(client: manager, url: manager.socketURL, options: nil)
+        
+        engine.onConnect = {
+            expect.fulfill()
+        }
+        manager.setTestStatus(.connecting)
+        manager.setCurrentReconnect(currentReconnect: 0)
+        manager.engine = engine
+        
+        manager.connect()
+
+        waitForExpectations(timeout: 0.3)
+    }
+    
+    func testManagerCallConnectWhenConnectingAndMoreThanOneReconnect() {
+        setUpSockets()
+        
+        let expect = expectation(description: "The manager should call connect on the engine")
+        let engine = TestEngine(client: manager, url: manager.socketURL, options: nil)
+        
+        engine.onConnect = {
+            expect.fulfill()
+        }
+        manager.setTestStatus(.connecting)
+        manager.setCurrentReconnect(currentReconnect: 1)
+        manager.engine = engine
+        
+        manager.connect()
+
+        waitForExpectations(timeout: 0.8)
+    }
+
     func testManagerCallsDisconnect() {
         setUpSockets()
 
@@ -154,6 +192,10 @@ public enum ManagerExpectation: String {
 }
 
 public class TestManager: SocketManager {
+    public func setCurrentReconnect(currentReconnect: Int) {
+        self.currentReconnectAttempt = currentReconnect
+    }
+    
     public override func disconnect() {
         setTestStatus(.disconnected)
     }

Tests/TestSocketIO/SocketSideEffectTest.swift

@@ -487,7 +487,7 @@ class TestEngine: SocketEngineSpec {
     private(set) var ws: WebSocket? = nil
     private(set) var version = SocketIOVersion.three
 
-    fileprivate var onConnect: (() -> ())?
+    internal var onConnect: (() -> ())?
 
     required init(client: SocketEngineClient, url: URL, options: [String: Any]?) {
         self.client = client

Usage Docs/15to16.md

@@ -6,11 +6,30 @@ This guide will help you navigate the changes that were introduced in v16.
 
 ## Client supports multiple socket.io versions
 
-The client now supports socket.io 3 servers. This is mostly a transparent change, however if your sever
+The client now supports socket.io 3 servers. This is mostly a transparent change, however if your server
 is socket.io 2, you must send `.version(.two)` as an option to the manager.
 
 ```swift
 SocketManager(socketURL: URL(string:"http://localhost:8087/")!, config: [.version(.two)])
 ```
 
+## How to upgrade
 
+- first, upgrade the Socket.IO server to v4 with the compatibility mode enabled (`allowEIO3: true`)
+- then, upgrade the clients to v16
+- finally, once all clients have upgraded, disable the compatibility mode
+
+You can check the version of the connection on the server side with:
+
+```js
+io.on("connection", (socket) => {
+  // either 3 for the 3rd revision of the protocol (Socket.IO v2) or 4 for the 4th revision (Socket.IO v3/v4)
+  const version = socket.conn.protocol;
+});
+```
+
+See also:
+
+- [Compatibility table](https://nuclearace.github.io/Socket.IO-Client-Swift/Compatibility.html)
+- Migrating from 2.x to 3.0: https://socket.io/docs/v4/migrating-from-2-x-to-3-0/
+- Migrating from 3.x to 4.0: https://socket.io/docs/v4/migrating-from-3-x-to-4-0/

Usage Docs/Compatibility.md

@@ -0,0 +1,61 @@
+Here is the compatibility table with the Node.js server:
+
+<table>
+    <tr>
+        <th rowspan="2">Swift Client version</th>
+        <th colspan="3">Socket.IO server version</th>
+    </tr>
+    <tr>
+        <td align="center">2.x</td>
+        <td align="center">3.x</td>
+        <td align="center">4.x</td>
+    </tr>
+    <tr>
+        <td align="center">v15.x</td>
+        <td align="center"><b>YES</b></td>
+        <td align="center"><b>YES</b><sup>1</sup></td>
+        <td align="center"><b>YES</b><sup>2</sup></td>
+    </tr>
+    <tr>
+        <td align="center">v16.x</td>
+        <td align="center"><b>YES</b><sup>3</sup></td>
+        <td align="center"><b>YES</b></td>
+        <td align="center"><b>YES</b></td>
+    </tr>
+</table>
+
+[1] Yes, with <code><a href="https://socket.io/docs/v4/server-initialization/#allowEIO3">allowEIO3: true</a></code> (server) and `.connectParams(["EIO": "3"])` (client):
+
+*Server*
+
+```js
+const { createServer } = require("http");
+const { Server } = require("socket.io");
+
+const httpServer = createServer();
+const io = new Server(httpServer, {
+  allowEIO3: true
+});
+
+httpServer.listen(8080);
+```
+
+*Client*
+
+```swift
+SocketManager(socketURL: URL(string:"http://localhost:8080/")!, config: [.connectParams(["EIO": "3"])])
+```
+
+[2] Yes, <code><a href="https://socket.io/docs/v4/server-initialization/#allowEIO3">allowEIO3: true</a></code> (server)
+
+[3] Yes, with `.version(.two)` (client):
+
+```swift
+SocketManager(socketURL: URL(string:"http://localhost:8080/")!, config: [.version(.two)])
+```
+
+See also:
+
+- Migrating from 2.x to 3.0: https://socket.io/docs/v4/migrating-from-2-x-to-3-0/
+- Migrating from 3.x to 4.0: https://socket.io/docs/v4/migrating-from-3-x-to-4-0/
+- Socket.IO protocol: https://github.com/socketio/socket.io-protocol