Merge branch 'development'

* development:
  update readme and changelog for new version
  add changelog entry for exponential backoff
  config setting and test updates for reconnectWaitMax and randomizationFactor
  add configurable exponential backoff
  Fix #1147
  Bump Starscream to 3.0.6
  Update to Swift 4.2

Author: nuclearace

Diff for: .swift-version

@@ -1,3 +1,9 @@
+# v14.0.0
+
+- Minimum version of the client is now Swift 4.2.
+- Add exponential backoff for reconnects, with `reconnectWaitMax` and `randomizationFactor` options [#1149](https://github.com/socketio/socket.io-client-swift/pull/1149)
+- `statusChange` event's data format adds a second value, the raw value of the status. This is for use in Objective-C. [#1147](https://github.com/socketio/socket.io-client-swift/issues/1147)
+
 # v13.4.0
 
 - Add emits with write completion handlers. [#1096](https://github.com/socketio/socket.io-client-swift/issues/1096)
@@ -69,4 +75,3 @@ Important API changes
 - Adds `.sentPing` and `.gotPong` client events for tracking ping/pongs.
 - Makes the framework a single target.
 - Updates Starscream to 3.0
-

Diff for: CHANGELOG.md

@@ -1,4 +1,4 @@
-// swift-tools-version:4.0
+// swift-tools-version:4.2
 
 import PackageDescription
 

Diff for: Package.swift

@@ -63,7 +63,7 @@ SocketIOClient* socket = manager.defaultSocket;
 ## FAQS
 Checkout the [FAQs](https://nuclearace.github.io/Socket.IO-Client-Swift/faq.html) for commonly asked questions.
 
-Checkout the [12to13](https://nuclearace.github.io/Socket.IO-Client-Swift/12to13.html) guide for migrating to v13.
+Checkout the [12to13](https://nuclearace.github.io/Socket.IO-Client-Swift/12to13.html) guide for migrating to v13+ from v12 below.
 
 
 ## Installation
@@ -76,7 +76,7 @@ If you need Swift 3.x use v11.1.3.
 ### Swift Package Manager
 Add the project as a dependency to your Package.swift:
 ```swift
-// swift-tools-version:4.0
+// swift-tools-version:4.2
 
 import PackageDescription
 
@@ -86,7 +86,7 @@ let package = Package(
         .executable(name: "socket.io-test", targets: ["YourTargetName"])
     ],
     dependencies: [
-        .package(url: "https://github.com/socketio/socket.io-client-swift", .upToNextMinor(from: "13.3.0"))
+        .package(url: "https://github.com/socketio/socket.io-client-swift", .upToNextMinor(from: "14.0.0"))
     ],
     targets: [
         .target(name: "YourTargetName", dependencies: ["SocketIO"], path: "./Path/To/Your/Sources")
@@ -99,7 +99,7 @@ Then import `import SocketIO`.
 ### Carthage
 Add this line to your `Cartfile`:
 ```
-github "socketio/socket.io-client-swift" ~> 13.3.0
+github "socketio/socket.io-client-swift" ~> 14.0.0
 ```
 
 Run `carthage update --platform ios,macosx`.
@@ -113,7 +113,7 @@ Create `Podfile` and add `pod 'Socket.IO-Client-Swift'`:
 use_frameworks!
 
 target 'YourApp' do
-    pod 'Socket.IO-Client-Swift', '~> 13.3.0'
+    pod 'Socket.IO-Client-Swift', '~> 14.0.0'
 end
 ```
 

Diff for: README.md

@@ -21,9 +21,11 @@ Pod::Spec.new do |s|
     :tag => 'v13.4.0',
     :submodules => true
   }
+
+  s.swift_version = "4.2"
   s.pod_target_xcconfig = {
       'SWIFT_VERSION' => '4.0'
   }
   s.source_files  = "Source/SocketIO/**/*.swift", "Source/SocketIO/*.swift"
-  s.dependency "Starscream", "~> 3.0.2"
+  s.dependency "Starscream", "~> 3.0.6"
 end

Diff for: Socket.IO-Client-Swift.podspec

@@ -9,6 +9,7 @@
 /* Begin PBXBuildFile section */
 		1C6572803D7E252A77A86E5F /* SocketManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1C65763817782DFAC67BE05C /* SocketManager.swift */; };
 		1C6573B22DC9423CDFC32F05 /* SocketRawView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1C657533E849FC3E4342C602 /* SocketRawView.swift */; };
+		1C657CDE5D510E8E2E573E39 /* utils.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1C6577B639C34EE1C8829D9A /* utils.swift */; };
 		1C657FBB3F670261780FD72E /* SocketManagerSpec.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1C6574AF9687A213814753E4 /* SocketManagerSpec.swift */; };
 		1C686BE21F869AFD007D8627 /* SocketIOClientConfigurationTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1C686BD21F869AF1007D8627 /* SocketIOClientConfigurationTest.swift */; };
 		1C686BE31F869AFD007D8627 /* SocketEngineTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1C686BD31F869AF1007D8627 /* SocketEngineTest.swift */; };
@@ -64,6 +65,7 @@
 		1C6574AF9687A213814753E4 /* SocketManagerSpec.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SocketManagerSpec.swift; sourceTree = "<group>"; };
 		1C657533E849FC3E4342C602 /* SocketRawView.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SocketRawView.swift; sourceTree = "<group>"; };
 		1C65763817782DFAC67BE05C /* SocketManager.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SocketManager.swift; sourceTree = "<group>"; };
+		1C6577B639C34EE1C8829D9A /* utils.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = utils.swift; sourceTree = "<group>"; };
 		1C686BD21F869AF1007D8627 /* SocketIOClientConfigurationTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SocketIOClientConfigurationTest.swift; sourceTree = "<group>"; };
 		1C686BD31F869AF1007D8627 /* SocketEngineTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SocketEngineTest.swift; sourceTree = "<group>"; };
 		1C686BD41F869AF1007D8627 /* SocketSideEffectTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SocketSideEffectTest.swift; sourceTree = "<group>"; };
@@ -159,6 +161,7 @@
 				1C686BD71F869AF1007D8627 /* SocketParserTest.swift */,
 				1C686BD81F869AF1007D8627 /* SocketNamespacePacketTest.swift */,
 				DD52BBAC5FAA7730D32CD5BF /* SocketMangerTest.swift */,
+				1C6577B639C34EE1C8829D9A /* utils.swift */,
 			);
 			name = TestSocketIO;
 			path = Tests/TestSocketIO;
@@ -501,6 +504,7 @@
 				1C686BE81F869AFD007D8627 /* SocketNamespacePacketTest.swift in Sources */,
 				DD52BCCD25EFA76E0F9B313C /* SocketMangerTest.swift in Sources */,
 				DD52B53F2609D91A683DFCDD /* ManagerObjectiveCTest.m in Sources */,
+				1C657CDE5D510E8E2E573E39 /* utils.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Diff for: Socket.IO-Client-Swift.xcodeproj/project.pbxproj

@@ -83,7 +83,7 @@ open class SocketIOClient : NSObject, SocketIOClientSpec {
     @objc
     public private(set) var status = SocketIOStatus.notConnected {
         didSet {
-            handleClientEvent(.statusChange, data: [status])
+            handleClientEvent(.statusChange, data: [status, status.rawValue])
         }
     }
 

Diff for: Source/SocketIO/Client/SocketIOClient.swift

@@ -75,8 +75,14 @@ public enum SocketIOClientOption : ClientOption {
     /// The number of times to try and reconnect before giving up. Pass `-1` to [never give up](https://www.youtube.com/watch?v=dQw4w9WgXcQ).
     case reconnectAttempts(Int)
 
-    /// The number of seconds to wait before reconnect attempts.
+    /// The minimum number of seconds to wait before reconnect attempts.
     case reconnectWait(Int)
+    
+    /// The maximum number of seconds to wait before reconnect attempts.
+    case reconnectWaitMax(Int)
+    
+    /// The randomization factor for calculating reconnect jitter.
+    case randomizationFactor(Double)
 
     /// Set `true` if your server is using secure transports.
     case secure(Bool)
@@ -125,6 +131,10 @@ public enum SocketIOClientOption : ClientOption {
             description = "reconnectAttempts"
         case .reconnectWait:
             description = "reconnectWait"
+        case .reconnectWaitMax:
+            description = "reconnectWaitMax"
+        case .randomizationFactor:
+            description = "randomizationFactor"
         case .secure:
             description = "secure"
         case .selfSigned:
@@ -170,6 +180,10 @@ public enum SocketIOClientOption : ClientOption {
             value = attempts
         case let .reconnectWait(wait):
             value = wait
+        case let .reconnectWaitMax(wait):
+            value = wait
+        case let .randomizationFactor(factor):
+            value = factor
         case let .secure(secure):
             value = secure
         case let .security(security):

Diff for: Source/SocketIO/Client/SocketIOClientOption.swift

@@ -327,6 +327,9 @@ public enum SocketClientEvent : String {
 
     /// Emitted every time there is a change in the client's status.
     ///
+    /// The payload for data is [SocketIOClientStatus, Int]. Where the second item is the raw value. Use the second one
+    /// if you are working in Objective-C.
+    ///
     /// Usage:
     ///
     /// ```swift

Diff for: Source/SocketIO/Client/SocketIOClientSpec.swift

@@ -97,9 +97,15 @@ open class SocketManager : NSObject, SocketManagerSpec, SocketParsable, SocketDa
     /// If `true`, this client will try and reconnect on any disconnects.
     public var reconnects = true
 
-    /// The number of seconds to wait before attempting to reconnect.
+    /// The minimum number of seconds to wait before attempting to reconnect.
     public var reconnectWait = 10
 
+    /// The maximum number of seconds to wait before attempting to reconnect.
+    public var reconnectWaitMax = 30
+
+    /// The randomization factor for calculating reconnect jitter.
+    public var randomizationFactor = 0.5
+
     /// The status of this manager.
     public private(set) var status: SocketIOStatus = .notConnected {
         didSet {
@@ -474,7 +480,21 @@ open class SocketManager : NSObject, SocketManagerSpec, SocketParsable, SocketDa
         currentReconnectAttempt += 1
         connect()
 
-        handleQueue.asyncAfter(deadline: DispatchTime.now() + Double(reconnectWait), execute: _tryReconnect)
+        let interval = reconnectInterval(attempts: currentReconnectAttempt)
+        DefaultSocketLogger.Logger.log("Scheduling reconnect in \(interval)s", type: SocketManager.logType)
+        handleQueue.asyncAfter(deadline: DispatchTime.now() + interval, execute: _tryReconnect)
+    }
+
+    func reconnectInterval(attempts: Int) -> Double {
+        // apply exponential factor
+        let backoffFactor = pow(1.5, attempts)
+        let interval = Double(reconnectWait) * Double(truncating: backoffFactor as NSNumber)
+        // add in a random factor smooth thundering herds
+        let rand = Double.random(in: 0 ..< 1)
+        let randomFactor = rand * randomizationFactor * Double(truncating: interval as NSNumber)
+        // add in random factor, and clamp to min and max values
+        let combined = interval + randomFactor
+        return Double(fmax(Double(reconnectWait), fmin(combined, Double(reconnectWaitMax))))
     }
 
     /// Sets manager specific configs.
@@ -493,6 +513,10 @@ open class SocketManager : NSObject, SocketManagerSpec, SocketParsable, SocketDa
                 self.reconnectAttempts = attempts
             case let .reconnectWait(wait):
                 reconnectWait = abs(wait)
+            case let .reconnectWaitMax(wait):
+                reconnectWaitMax = abs(wait)
+            case let .randomizationFactor(factor):
+                randomizationFactor = factor
             case let .log(log):
                 DefaultSocketLogger.Logger.log = log
             case let .logger(logger):

Diff for: Source/SocketIO/Manager/SocketManager.swift

@@ -69,8 +69,14 @@ public protocol SocketManagerSpec : AnyObject, SocketEngineClient {
     /// If `true`, this manager will try and reconnect on any disconnects.
     var reconnects: Bool { get set }
 
-    /// The number of seconds to wait before attempting to reconnect.
+    /// The minimum number of seconds to wait before attempting to reconnect.
     var reconnectWait: Int { get set }
+    
+    /// The maximum number of seconds to wait before attempting to reconnect.
+    var reconnectWaitMax: Int { get set }
+
+    /// The randomization factor for calculating reconnect jitter.
+    var randomizationFactor: Double { get set }
 
     /// The URL of the socket.io server.
     var socketURL: URL { get }

Diff for: Source/SocketIO/Manager/SocketManagerSpec.swift

@@ -71,6 +71,10 @@ extension Dictionary where Key == String, Value == Any {
             return .reconnectAttempts(attempts)
         case let ("reconnectWait", wait as Int):
             return .reconnectWait(wait)
+        case let ("reconnectWaitMax", wait as Int):
+            return .reconnectWaitMax(wait)
+        case let ("randomizationFactor", factor as Double):
+            return .randomizationFactor(factor)
         case let ("secure", secure as Bool):
             return .secure(secure)
         case let ("security", security as SSLSecurity):

Diff for: Source/SocketIO/Util/SocketExtensions.swift

@@ -15,6 +15,8 @@ class SocketMangerTest : XCTestCase {
         XCTAssertEqual(manager.handleQueue, DispatchQueue.main)
         XCTAssertTrue(manager.reconnects)
         XCTAssertEqual(manager.reconnectWait, 10)
+        XCTAssertEqual(manager.reconnectWaitMax, 30)
+        XCTAssertEqual(manager.randomizationFactor, 0.5)
         XCTAssertEqual(manager.status, .notConnected)
     }
 
@@ -27,6 +29,21 @@ class SocketMangerTest : XCTestCase {
 
         XCTAssertEqual(manager.config.first!, .secure(true))
     }
+    
+    func testBackoffIntervalCalulation() {
+        XCTAssertLessThanOrEqual(manager.reconnectInterval(attempts: -1), Double(manager.reconnectWaitMax))
+        XCTAssertLessThanOrEqual(manager.reconnectInterval(attempts: 0), 15)
+        XCTAssertLessThanOrEqual(manager.reconnectInterval(attempts: 1), 22.5)
+        XCTAssertLessThanOrEqual(manager.reconnectInterval(attempts: 2), 33.75)
+        XCTAssertLessThanOrEqual(manager.reconnectInterval(attempts: 50), Double(manager.reconnectWaitMax))
+        XCTAssertLessThanOrEqual(manager.reconnectInterval(attempts: 10000), Double(manager.reconnectWaitMax))
+        
+        XCTAssertGreaterThanOrEqual(manager.reconnectInterval(attempts: -1), Double(manager.reconnectWait))
+        XCTAssertGreaterThanOrEqual(manager.reconnectInterval(attempts: 0), Double(manager.reconnectWait))
+        XCTAssertGreaterThanOrEqual(manager.reconnectInterval(attempts: 1), 15)
+        XCTAssertGreaterThanOrEqual(manager.reconnectInterval(attempts: 2), 22.5)
+        XCTAssertGreaterThanOrEqual(manager.reconnectInterval(attempts: 10000), Double(manager.reconnectWait))
+    }
 
     func testManagerCallsConnect() {
         setUpSockets()
@@ -90,13 +107,17 @@ class SocketMangerTest : XCTestCase {
             .forceNew(true),
             .reconnects(false),
             .reconnectWait(5),
+            .reconnectWaitMax(5),
+            .randomizationFactor(0.7),
             .reconnectAttempts(5)
         ])
 
         XCTAssertEqual(manager.handleQueue, queue)
         XCTAssertTrue(manager.forceNew)
         XCTAssertFalse(manager.reconnects)
         XCTAssertEqual(manager.reconnectWait, 5)
+        XCTAssertEqual(manager.reconnectWaitMax, 5)
+        XCTAssertEqual(manager.randomizationFactor, 0.7)
         XCTAssertEqual(manager.reconnectAttempts, 5)
     }
 

Diff for: Tests/TestSocketIO/SocketMangerTest.swift

@@ -0,0 +1,13 @@
+//
+// Created by Erik Little on 2019-01-11.
+//
+
+import Foundation
+@testable import SocketIO
+
+public class OBjcUtils: NSObject {
+    @objc
+    public static func setTestStatus(socket: SocketIOClient, status: SocketIOStatus) {
+        socket.setTestStatus(status)
+    }
+}

Diff for: Tests/TestSocketIO/utils.swift

@@ -34,6 +34,8 @@ - (void)testManagerProperties {
     XCTAssertEqual(self.manager.handleQueue, dispatch_get_main_queue());
     XCTAssertTrue(self.manager.reconnects);
     XCTAssertEqual(self.manager.reconnectWait, 10);
+    XCTAssertEqual(self.manager.reconnectWaitMax, 30);
+    XCTAssertEqual(self.manager.randomizationFactor, 0.5);
     XCTAssertEqual(self.manager.status, SocketIOStatusNotConnected);
 }
 

Diff for: Tests/TestSocketIOObjc/ManagerObjectiveCTest.m

@@ -7,6 +7,7 @@
 //  Merely tests whether the Objective-C api breaks
 //
 
+#import "SocketIO_Tests-Swift.h"
 #import "SocketObjectiveCTest.h"
 
 @import Dispatch;
@@ -73,11 +74,11 @@ - (void)testEmitWriteCompletionSyntax {
 
 - (void)testEmitWriteCompletion {
     XCTestExpectation* expect = [self expectationWithDescription:@"Write completion should be called"];
-    
+
     [self.socket emit:@"testEmit" with:@[@YES] completion:^{
         [expect fulfill];
     }];
-    
+
     [self waitForExpectationsWithTimeout:0.3 handler:nil];
 }
 
@@ -98,6 +99,19 @@ - (void)testSSLSecurity {
     sec = nil;
 }
 
+- (void)testStatusChangeHandler {
+    XCTestExpectation* expect = [self expectationWithDescription:@"statusChange should be correctly called"];
+
+    [self.socket on:@"statusChange" callback:^(NSArray* data, SocketAckEmitter* ack) {
+        XCTAssertTrue([data[1] integerValue] == SocketIOStatusConnecting);
+        [expect fulfill];
+    }];
+
+    [OBjcUtils setTestStatusWithSocket:self.socket status:SocketIOStatusConnecting];
+
+    [self waitForExpectationsWithTimeout:0.3 handler:nil];
+}
+
 - (void)setUp {
     [super setUp];
     NSURL* url = [[NSURL alloc] initWithString:@"http://localhost"];