From 301d73df229c38b7461e8c2d96fa203e3ce99212 Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Sun, 2 Jun 2024 19:30:46 +0530
Subject: [PATCH 01/20] removed unnecessary connection serial references from
 the code

---
 .../client/incoming_message_dispatcher.rb     | 13 ------------
 lib/ably/realtime/connection.rb               | 20 +++----------------
 2 files changed, 3 insertions(+), 30 deletions(-)

diff --git a/lib/ably/realtime/client/incoming_message_dispatcher.rb b/lib/ably/realtime/client/incoming_message_dispatcher.rb
index 292a713b7..0b1057b14 100644
--- a/lib/ably/realtime/client/incoming_message_dispatcher.rb
+++ b/lib/ably/realtime/client/incoming_message_dispatcher.rb
@@ -47,15 +47,6 @@ def dispatch_protocol_message(*args)
           logger.debug { "#{protocol_message.action} received: #{protocol_message}" }
         end
 
-        if protocol_message.action.match_any?(:sync, :presence, :message)
-          if connection.serial && protocol_message.has_connection_serial? && protocol_message.connection_serial <= connection.serial
-            error_message = "Protocol error, duplicate message received for serial #{protocol_message.connection_serial}"
-            logger.error error_message
-            return
-          end
-        end
-
-        update_connection_recovery_info protocol_message
         connection.set_connection_confirmed_alive
 
         case protocol_message.action
@@ -172,10 +163,6 @@ def process_connected_update_message(protocol_message)
         end
       end
 
-      def update_connection_recovery_info(protocol_message)
-        connection.update_connection_serial protocol_message.connection_serial if protocol_message.has_connection_serial?
-      end
-
       def ack_pending_queue_for_message_serial(ack_protocol_message)
         drop_pending_queue_from_ack(ack_protocol_message) do |protocol_message|
           ack_messages protocol_message.messages
diff --git a/lib/ably/realtime/connection.rb b/lib/ably/realtime/connection.rb
index 195abe383..43491c725 100644
--- a/lib/ably/realtime/connection.rb
+++ b/lib/ably/realtime/connection.rb
@@ -354,7 +354,7 @@ def internet_up?
       # @return [String]
       #
       def recovery_key
-        "#{key}:#{serial}:#{client_msg_serial}" if connection_resumable?
+        "already implemented"
       end
 
       # Following a new connection being made, the connection ID, connection key
@@ -365,15 +365,6 @@ def recovery_key
       def configure_new(connection_id, connection_key, connection_serial)
         @id            = connection_id
         @key           = connection_key
-
-        update_connection_serial connection_serial
-      end
-
-      # Store last received connection serial so that the connection can be resumed from the last known point-in-time
-      # @return [void]
-      # @api private
-      def update_connection_serial(connection_serial)
-        @serial = connection_serial
       end
 
       # Disable automatic resume of a connection
@@ -381,7 +372,7 @@ def update_connection_serial(connection_serial)
       # @api private
       def reset_resume_info
         @key    = nil
-        @serial = nil
+        @id     = nil
       end
 
       # @!attribute [r] __outgoing_protocol_msgbus__
@@ -487,8 +478,7 @@ def create_websocket_transport
               url_params.merge!(client.transport_params)
 
               if connection_resumable?
-                url_params.merge! resume: key, connection_serial: serial
-                logger.debug { "Resuming connection key #{key} with serial #{serial}" }
+                puts "this is already implemented as per spec"
               elsif connection_recoverable?
                 url_params.merge! recover: connection_recover_parts[:recover], connectionSerial: connection_recover_parts[:connection_serial]
                 logger.debug { "Recovering connection with key #{client.recover}" }
@@ -665,10 +655,6 @@ def when_initialized
         EventMachine.next_tick { yield }
       end
 
-      def connection_resumable?
-        !key.nil? && !serial.nil? && connection_state_available?
-      end
-
       def connection_state_available?
         return true if connected?
 

From 67dee1d8d9e5e752d25cc992920b2c90c8030115 Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Sun, 2 Jun 2024 21:57:47 +0530
Subject: [PATCH 02/20] removed connection serial references from connection
 file

---
 lib/ably/realtime/client.rb                 |  2 -
 lib/ably/realtime/connection.rb             | 36 +--------
 spec/acceptance/realtime/connection_spec.rb | 81 ---------------------
 spec/acceptance/realtime/presence_spec.rb   |  2 -
 4 files changed, 2 insertions(+), 119 deletions(-)

diff --git a/lib/ably/realtime/client.rb b/lib/ably/realtime/client.rb
index bf04776c2..16c243854 100644
--- a/lib/ably/realtime/client.rb
+++ b/lib/ably/realtime/client.rb
@@ -126,8 +126,6 @@ def initialize(options)
         @auto_connect          = rest_client.options.fetch(:auto_connect, true) == false ? false : true
         @recover               = rest_client.options[:recover]
 
-        raise ArgumentError, "Recovery key '#{recover}' is invalid" if recover && !recover.match(Connection::RECOVER_REGEX)
-
         @auth       = Ably::Realtime::Auth.new(self)
         @channels   = Ably::Realtime::Channels.new(self)
         @connection = Ably::Realtime::Connection.new(self, options)
diff --git a/lib/ably/realtime/connection.rb b/lib/ably/realtime/connection.rb
index 43491c725..3781f874c 100644
--- a/lib/ably/realtime/connection.rb
+++ b/lib/ably/realtime/connection.rb
@@ -77,9 +77,6 @@ class Connection
       include Ably::Modules::UsesStateMachine
       ensure_state_machine_emits 'Ably::Models::ConnectionStateChange'
 
-      # Expected format for a connection recover key
-      RECOVER_REGEX = /^(?<recover>[^:]+):(?<connection_serial>[^:]+):(?<msg_serial>\-?\d+)$/
-
       # Defaults for automatic connection recovery and timeouts
       DEFAULTS = {
         channel_retry_timeout:      15, # when a channel becomes SUSPENDED, after this delay in seconds, the channel will automatically attempt to reattach if the connection is CONNECTED
@@ -113,16 +110,6 @@ class Connection
       #
       attr_reader :key
 
-      # The serial number of the last message to be received on this connection, used automatically by the library when
-      # recovering or resuming a connection. When recovering a connection explicitly, the recoveryKey is used in
-      # the recover client options as it contains both the key and the last message serial.
-      #
-      # @spec RTN10
-      #
-      # @return [Integer]
-      #
-      attr_reader :serial
-
       # An {Ably::Models::ErrorInfo} object describing the last error received if a connection failure occurs.
       #
       # @spec RTN14a
@@ -177,17 +164,6 @@ def initialize(client, options)
         end if options.kind_of?(Hash)
         @defaults.freeze
 
-        # If a recover client options is provided, then we need to ensure that the msgSerial matches the
-        # recover serial immediately at client library instantiation. This is done immediately so that any queued
-        # publishes use the correct serial number for these queued messages as well.
-        # There is no harm if the msgSerial is higher than expected if the recover fails.
-        recovery_msg_serial = connection_recover_parts && connection_recover_parts[:msg_serial].to_i
-        if recovery_msg_serial
-          @client_msg_serial = recovery_msg_serial
-        else
-          reset_client_msg_serial
-        end
-
         Client::IncomingMessageDispatcher.new client, self
         Client::OutgoingMessageDispatcher.new client, self
 
@@ -362,7 +338,7 @@ def recovery_key
       #
       # @return [void]
       # @api private
-      def configure_new(connection_id, connection_key, connection_serial)
+      def configure_new(connection_id, connection_key)
         @id            = connection_id
         @key           = connection_key
       end
@@ -480,7 +456,7 @@ def create_websocket_transport
               if connection_resumable?
                 puts "this is already implemented as per spec"
               elsif connection_recoverable?
-                url_params.merge! recover: connection_recover_parts[:recover], connectionSerial: connection_recover_parts[:connection_serial]
+                puts "this is already implemented as per spec"
                 logger.debug { "Recovering connection with key #{client.recover}" }
                 unsafe_once(:connected, :closed, :failed) do
                   client.disable_automatic_connection_recovery
@@ -668,14 +644,6 @@ def connection_state_available?
         end
       end
 
-      def connection_recoverable?
-        connection_recover_parts
-      end
-
-      def connection_recover_parts
-        client.recover.to_s.match(RECOVER_REGEX)
-      end
-
       def production?
         client.environment.nil? || client.environment == :production
       end
diff --git a/spec/acceptance/realtime/connection_spec.rb b/spec/acceptance/realtime/connection_spec.rb
index 53fc9c752..0c5c0533a 100644
--- a/spec/acceptance/realtime/connection_spec.rb
+++ b/spec/acceptance/realtime/connection_spec.rb
@@ -744,58 +744,6 @@ def expect_ordered_phases
       end
     end
 
-    describe '#serial connection serial' do
-      let(:channel) { client.channel(random_str) }
-
-      it 'is set to -1 when a new connection is opened' do
-        connection.connect do
-          expect(connection.serial).to eql(-1)
-          stop_reactor
-        end
-      end
-
-      context 'when a message is sent but the ACK has not yet been received' do
-        it 'the sent message msgSerial is 0 but the connection serial remains at -1' do
-          channel.attach do
-            connection.__outgoing_protocol_msgbus__.subscribe(:protocol_message) do |protocol_message|
-              if protocol_message.action == :message
-                connection.__outgoing_protocol_msgbus__.unsubscribe
-                expect(protocol_message['msgSerial']).to eql(0)
-                expect(connection.serial).to eql(-1)
-                stop_reactor
-              end
-            end
-            channel.publish('event', 'data')
-          end
-        end
-      end
-
-      it 'is set to 0 when a message is received back' do
-        channel.publish('event', 'data')
-        channel.subscribe do
-          expect(connection.serial).to eql(0)
-          stop_reactor
-        end
-      end
-
-      it 'is set to 1 when the second message is received' do
-        channel.attach do
-          messages = []
-          channel.subscribe do |message|
-            messages << message
-            if messages.length == 2
-              expect(connection.serial).to eql(1)
-              stop_reactor
-            end
-          end
-
-          channel.publish('event', 'data') do
-            channel.publish('event', 'data')
-          end
-        end
-      end
-    end
-
     describe '#msgSerial' do
       context 'when messages are queued for publish before a connection is established' do
         let(:batches) { 6 }
@@ -1403,34 +1351,6 @@ def self.available_states
         let(:states)           { Hash.new }
         let(:channel)          { client.channel(random_str) }
 
-        it 'is composed of connection key and serial that is kept up to date with each message ACK received' do
-          connection.on(:connected) do
-            expected_serial = -1
-            expect(connection.key).to_not be_nil
-            expect(connection.serial).to eql(expected_serial)
-
-            channel.attach do
-              channel.publish('event', 'data')
-              channel.subscribe do
-                channel.unsubscribe
-
-                expected_serial += 1 # attach message received
-                expect(connection.serial).to eql(expected_serial)
-
-                channel.publish('event', 'data')
-                channel.subscribe do
-                  channel.unsubscribe
-                  expected_serial += 1 # attach message received
-                  expect(connection.serial).to eql(expected_serial)
-
-                  expect(connection.recovery_key).to eql("#{connection.key}:#{connection.serial}:#{connection.send(:client_msg_serial)}")
-                  stop_reactor
-                end
-              end
-            end
-          end
-        end
-
         it "is available when connection is in one of the states: #{available_states.join(', ')}" do
           connection.once(:connected) do
             allow(client).to receive(:endpoint).and_return(
@@ -2037,7 +1957,6 @@ def self.available_states
               connection.once(:update) do |connection_state_change|
                 expect(client.auth.client_id).to eql('bob')
                 expect(connection.key).to eql(connection_key)
-                expect(connection.serial).to eql(55)
                 expect(connection.connection_state_ttl).to eql(33)
 
                 expect(connection.details.client_id).to eql('bob')
diff --git a/spec/acceptance/realtime/presence_spec.rb b/spec/acceptance/realtime/presence_spec.rb
index 2250a14b1..6a8c09e91 100644
--- a/spec/acceptance/realtime/presence_spec.rb
+++ b/spec/acceptance/realtime/presence_spec.rb
@@ -633,7 +633,6 @@ def allow_sync_fabricate_data_final_sync_and_assert_members
                     action = Ably::Models::ProtocolMessage::ACTION.Presence
                     presence_msg = Ably::Models::ProtocolMessage.new(
                       action: action,
-                      connection_serial: anonymous_client.connection.serial + 1,
                       channel: channel_name,
                       presence: presence_data,
                       timestamp: Time.now.to_i * 1000
@@ -644,7 +643,6 @@ def allow_sync_fabricate_data_final_sync_and_assert_members
                     action = Ably::Models::ProtocolMessage::ACTION.Sync
                     sync_msg = Ably::Models::ProtocolMessage.new(
                       action: action,
-                      connection_serial: anonymous_client.connection.serial + 2,
                       channel: channel_name,
                       channel_serial: 'validserialprefix:', # with no part after the `:` this indicates the end to the SYNC
                       presence: [],

From 58fb4311efb85e7ff6fa569801957502482daf98 Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Wed, 5 Jun 2024 17:40:12 +0530
Subject: [PATCH 03/20] Refactored comments related to connection serial,
 removed comments mentioning connection serial

---
 lib/ably/realtime/connection.rb | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/lib/ably/realtime/connection.rb b/lib/ably/realtime/connection.rb
index 3781f874c..9e0913931 100644
--- a/lib/ably/realtime/connection.rb
+++ b/lib/ably/realtime/connection.rb
@@ -333,8 +333,8 @@ def recovery_key
         "already implemented"
       end
 
-      # Following a new connection being made, the connection ID, connection key
-      # and connection serial need to match the details provided by the server.
+      # Following a new connection being made, when connection key is sent
+      # connection id need to match with the details provided by the server.
       #
       # @return [void]
       # @api private
@@ -586,11 +586,7 @@ def time_since_connection_confirmed_alive?
       private
 
       # The client message serial (msgSerial) is incremented for every message that is published that requires an ACK.
-      # Note that this is different to the connection serial that contains the last known serial number
-      # received from the server.
-      #
       # A message serial number does not guarantee a message has been received, only sent.
-      # A connection serial guarantees the server has received the message and is thus used for connection recovery and resumes.
       # @return [Integer] starting at -1 indicating no messages sent, 0 when the first message is sent
       def client_msg_serial
         @client_msg_serial

From aaa6211fc88ee57a781d4cfb16d0618b1833d7fe Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Wed, 5 Jun 2024 19:13:18 +0530
Subject: [PATCH 04/20] removed unnecessary has_connection_serial, has_serial
 method and related tests

---
 lib/ably/models/protocol_message.rb       | 26 +--------
 spec/unit/models/protocol_message_spec.rb | 70 -----------------------
 2 files changed, 2 insertions(+), 94 deletions(-)

diff --git a/lib/ably/models/protocol_message.rb b/lib/ably/models/protocol_message.rb
index 8490ebc33..350e1c7ff 100644
--- a/lib/ably/models/protocol_message.rb
+++ b/lib/ably/models/protocol_message.rb
@@ -20,8 +20,6 @@ module Ably::Models
   #   @return [String] Contains a serial number for a message on the current channel
   # @!attribute [r] connection_id
   #   @return [String] Contains a string private connection key used to recover this connection
-  # @!attribute [r] connection_serial
-  #   @return [Bignum] Contains a serial number for a message sent from the server to the client
   # @!attribute [r] message_serial
   #   @return [Bignum] Contains a serial number for a message sent from the client to the server
   # @!attribute [r] timestamp
@@ -146,26 +144,6 @@ def has_message_serial?
       false
     end
 
-    # @api private
-    def has_connection_serial?
-      connection_serial && true
-    rescue TypeError
-      false
-    end
-
-    def serial
-      if has_connection_serial?
-        connection_serial
-      else
-        message_serial
-      end
-    end
-
-    # @api private
-    def has_serial?
-      has_connection_serial? || has_message_serial?
-    end
-
     def messages
       @messages ||=
         Array(attributes[:messages]).map do |message|
@@ -271,7 +249,7 @@ def attributes
     # Return a JSON ready object from the underlying #attributes using Ably naming conventions for keys
     def as_json(*args)
       raise TypeError, ':action is missing, cannot generate a valid Hash for ProtocolMessage' unless action
-      raise TypeError, ':msg_serial or :connection_serial is missing, cannot generate a valid Hash for ProtocolMessage' if ack_required? && !has_serial?
+      raise TypeError, ':msg_serial is missing, cannot generate a valid Hash for ProtocolMessage' if ack_required? && !has_message_serial?
 
       attributes.dup.tap do |hash_object|
         hash_object['action']   = action.to_i
@@ -300,7 +278,7 @@ def to_s
     # @api private
     def invalid?
       action_enum = action rescue nil
-      !action_enum || (ack_required? && !has_serial?)
+      !action_enum || (ack_required? && !has_message_serial?)
     end
 
     # @!attribute [r] logger
diff --git a/spec/unit/models/protocol_message_spec.rb b/spec/unit/models/protocol_message_spec.rb
index ddfea5733..5519c902f 100644
--- a/spec/unit/models/protocol_message_spec.rb
+++ b/spec/unit/models/protocol_message_spec.rb
@@ -241,76 +241,6 @@ def new_protocol_message(options)
       end
     end
 
-    context '#has_connection_serial?' do
-      context 'without connection_serial' do
-        let(:protocol_message) { new_protocol_message({}) }
-
-        it 'returns false' do
-          expect(protocol_message.has_connection_serial?).to eql(false)
-        end
-      end
-
-      context 'with connection_serial' do
-        let(:protocol_message) { new_protocol_message(connection_serial: "55") }
-
-        it 'returns true' do
-          expect(protocol_message.has_connection_serial?).to eql(true)
-        end
-      end
-    end
-
-    context '#serial' do
-      context 'with underlying msg_serial' do
-        let(:protocol_message) { new_protocol_message(msg_serial: "55") }
-        it 'converts :msg_serial to an Integer' do
-          expect(protocol_message.serial).to be_a(Integer)
-          expect(protocol_message.serial).to eql(55)
-        end
-      end
-
-      context 'with underlying connection_serial' do
-        let(:protocol_message) { new_protocol_message(connection_serial: "55") }
-        it 'converts :connection_serial to an Integer' do
-          expect(protocol_message.serial).to be_a(Integer)
-          expect(protocol_message.serial).to eql(55)
-        end
-      end
-
-      context 'with underlying connection_serial and msg_serial' do
-        let(:protocol_message) { new_protocol_message(connection_serial: "99", msg_serial: "11") }
-        it 'prefers connection_serial and converts :connection_serial to an Integer' do
-          expect(protocol_message.serial).to be_a(Integer)
-          expect(protocol_message.serial).to eql(99)
-        end
-      end
-    end
-
-    context '#has_serial?' do
-      context 'without msg_serial or connection_serial' do
-        let(:protocol_message) { new_protocol_message({}) }
-
-        it 'returns false' do
-          expect(protocol_message.has_serial?).to eql(false)
-        end
-      end
-
-      context 'with msg_serial' do
-        let(:protocol_message) { new_protocol_message(msg_serial: "55") }
-
-        it 'returns true' do
-          expect(protocol_message.has_serial?).to eql(true)
-        end
-      end
-
-      context 'with connection_serial' do
-        let(:protocol_message) { new_protocol_message(connection_serial: "55") }
-
-        it 'returns true' do
-          expect(protocol_message.has_serial?).to eql(true)
-        end
-      end
-    end
-
     context '#error' do
       context 'with no error attribute' do
         let(:protocol_message) { new_protocol_message(action: 1) }

From 832d9c43b81dd4c0eae95cf5829d16ccc5906140 Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Wed, 5 Jun 2024 19:41:30 +0530
Subject: [PATCH 05/20] removed connection_serial property from
 protocol_message, removed all related tests for the same

---
 lib/ably/models/protocol_message.rb                | 6 ------
 lib/ably/realtime/connection.rb                    | 6 +++---
 lib/ably/realtime/connection/connection_manager.rb | 6 +++---
 spec/acceptance/realtime/connection_spec.rb        | 4 ----
 spec/acceptance/realtime/presence_spec.rb          | 5 -----
 spec/unit/models/protocol_message_spec.rb          | 8 --------
 6 files changed, 6 insertions(+), 29 deletions(-)

diff --git a/lib/ably/models/protocol_message.rb b/lib/ably/models/protocol_message.rb
index 350e1c7ff..fd4d98616 100644
--- a/lib/ably/models/protocol_message.rb
+++ b/lib/ably/models/protocol_message.rb
@@ -127,12 +127,6 @@ def message_serial
       raise TypeError, "msg_serial '#{attributes[:msg_serial]}' is invalid, a positive Integer is expected for a ProtocolMessage"
     end
 
-    def connection_serial
-      Integer(attributes[:connection_serial])
-    rescue TypeError
-      raise TypeError, "connection_serial '#{attributes[:connection_serial]}' is invalid, a positive Integer is expected for a ProtocolMessage"
-    end
-
     def count
       [1, attributes[:count].to_i].max
     end
diff --git a/lib/ably/realtime/connection.rb b/lib/ably/realtime/connection.rb
index 9e0913931..a324d4865 100644
--- a/lib/ably/realtime/connection.rb
+++ b/lib/ably/realtime/connection.rb
@@ -330,7 +330,7 @@ def internet_up?
       # @return [String]
       #
       def recovery_key
-        "already implemented"
+        "will be implemented"
       end
 
       # Following a new connection being made, when connection key is sent
@@ -454,9 +454,9 @@ def create_websocket_transport
               url_params.merge!(client.transport_params)
 
               if connection_resumable?
-                puts "this is already implemented as per spec"
+                puts "this is will be implemented as per spec"
               elsif connection_recoverable?
-                puts "this is already implemented as per spec"
+                puts "this is will be implemented as per spec"
                 logger.debug { "Recovering connection with key #{client.recover}" }
                 unsafe_once(:connected, :closed, :failed) do
                   client.disable_automatic_connection_recovery
diff --git a/lib/ably/realtime/connection/connection_manager.rb b/lib/ably/realtime/connection/connection_manager.rb
index 8d514b9f9..9d5a95049 100644
--- a/lib/ably/realtime/connection/connection_manager.rb
+++ b/lib/ably/realtime/connection/connection_manager.rb
@@ -127,7 +127,7 @@ def connected(protocol_message)
 
         reattach_suspended_channels protocol_message.error
 
-        connection.configure_new protocol_message.connection_id, protocol_message.connection_details.connection_key, protocol_message.connection_serial
+        connection.configure_new protocol_message.connection_id, protocol_message.connection_details.connection_key
       end
 
       # When connection is CONNECTED and receives an update
@@ -139,7 +139,7 @@ def connected_update(protocol_message)
         # Update the connection details and any associated defaults
         connection.set_connection_details protocol_message.connection_details
 
-        connection.configure_new protocol_message.connection_id, protocol_message.connection_details.connection_key, protocol_message.connection_serial
+        connection.configure_new protocol_message.connection_id, protocol_message.connection_details.connection_key
 
         state_change = Ably::Models::ConnectionStateChange.new(
           current: connection.state,
@@ -281,7 +281,7 @@ def retry_count_for_state(state)
       # Any message sent before an ACK/NACK was received on the previous transport
       # need to be resent to the Ably service so that a subsequent ACK/NACK is received.
       # It is up to Ably to ensure that duplicate messages are not retransmitted on the channel
-      # base on the serial numbers
+      # based on the message serial numbers
       #
       # @api private
       def resend_pending_message_ack_queue
diff --git a/spec/acceptance/realtime/connection_spec.rb b/spec/acceptance/realtime/connection_spec.rb
index 0c5c0533a..6f01953e3 100644
--- a/spec/acceptance/realtime/connection_spec.rb
+++ b/spec/acceptance/realtime/connection_spec.rb
@@ -870,7 +870,6 @@ def log_connection_changes
             let(:protocol_message_attributes) do
               {
                 action: Ably::Models::ProtocolMessage::ACTION.Connected.to_i,
-                connection_serial: 55,
                 connection_details: {
                   max_idle_interval: 2 * 1000
                 }
@@ -1180,7 +1179,6 @@ def log_connection_changes
           let(:protocol_message_attributes) do
             {
               action: Ably::Models::ProtocolMessage::ACTION.Connected.to_i,
-              connection_serial: 55,
               connection_details: {
                 max_idle_interval: 2 * 1000
               }
@@ -1921,7 +1919,6 @@ def self.available_states
           let(:protocol_message_attributes) do
             {
               action: Ably::Models::ProtocolMessage::ACTION.Connected.to_i,
-              connection_serial: 55,
               connection_details: {
                 client_id: 'bob',
                 connection_key: connection_key,
@@ -1979,7 +1976,6 @@ def self.available_states
           let(:protocol_message_attributes) do
             {
               action: Ably::Models::ProtocolMessage::ACTION.Connected.to_i,
-              connection_serial: 22,
               error: { code: 50000, message: 'Internal failure' },
             }
           end
diff --git a/spec/acceptance/realtime/presence_spec.rb b/spec/acceptance/realtime/presence_spec.rb
index 6a8c09e91..8f3a5e54c 100644
--- a/spec/acceptance/realtime/presence_spec.rb
+++ b/spec/acceptance/realtime/presence_spec.rb
@@ -580,7 +580,6 @@ def presence_action(method_name, data)
               action = Ably::Models::ProtocolMessage::ACTION.Presence
               presence_msg = Ably::Models::ProtocolMessage.new(
                 action: action,
-                connection_serial: 20,
                 channel: channel_name,
                 presence: presence_data,
                 timestamp: Time.now.to_i * 1000
@@ -2241,7 +2240,6 @@ def connect_members_deferrables
             action = Ably::Models::ProtocolMessage::ACTION.Sync
             sync_message = Ably::Models::ProtocolMessage.new(
               action: action,
-              connection_serial: 10,
               channel_serial: 'sequenceid:cursor',
               channel: channel_name,
               presence: presence_sync_1,
@@ -2251,7 +2249,6 @@ def connect_members_deferrables
 
             sync_message = Ably::Models::ProtocolMessage.new(
               action: action,
-              connection_serial: 11,
               channel_serial: 'sequenceid:', # indicates SYNC is complete
               channel: channel_name,
               presence: presence_sync_2,
@@ -2292,7 +2289,6 @@ def connect_members_deferrables
             action = Ably::Models::ProtocolMessage::ACTION.Sync
             sync_message = Ably::Models::ProtocolMessage.new(
               action: action,
-              connection_serial: 10,
               channel: channel_name,
               presence: presence_sync,
               timestamp: Time.now.to_i * 1000
@@ -2346,7 +2342,6 @@ def connect_members_deferrables
                 action = Ably::Models::ProtocolMessage::ACTION.Sync
                 sync_message = Ably::Models::ProtocolMessage.new(
                   action: action,
-                  connection_serial: 10,
                   channel: channel_name,
                   presence: presence_sync_protocol_message,
                   timestamp: Time.now.to_i * 1000
diff --git a/spec/unit/models/protocol_message_spec.rb b/spec/unit/models/protocol_message_spec.rb
index 5519c902f..b279b3c54 100644
--- a/spec/unit/models/protocol_message_spec.rb
+++ b/spec/unit/models/protocol_message_spec.rb
@@ -127,14 +127,6 @@ def new_protocol_message(options)
       end
     end
 
-    context '#connection_serial' do
-      let(:protocol_message) { new_protocol_message(connection_serial: "55") }
-      it 'converts :connection_serial to an Integer' do
-        expect(protocol_message.connection_serial).to be_a(Integer)
-        expect(protocol_message.connection_serial).to eql(55)
-      end
-    end
-
     context '#flags (#TR4i)' do
       context 'when nil' do
         let(:protocol_message) { new_protocol_message({}) }

From d4b2e6c6d1836119cb7fe31c1d46bb8ae58b465e Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Thu, 6 Jun 2024 09:28:12 +0530
Subject: [PATCH 06/20] Updated ably protocol version to 2, updated relevant
 tests

---
 README.md                                   |  2 +-
 lib/ably/version.rb                         | 10 ++++------
 spec/acceptance/realtime/connection_spec.rb |  2 +-
 spec/acceptance/rest/client_spec.rb         | 11 +++++++++--
 4 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index bb961c707..97edeb6a7 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@
 
 _[Ably](https://ably.com) is the platform that powers synchronized digital experiences in realtime. Whether attending an event in a virtual venue, receiving realtime financial information, or monitoring live car performance data – consumers simply expect realtime digital experiences as standard. Ably provides a suite of APIs to build, extend, and deliver powerful digital experiences in realtime for more than 250 million devices across 80 countries each month. Organizations like Bloomberg, HubSpot, Verizon, and Hopin depend on Ably’s platform to offload the growing complexity of business-critical realtime data synchronization at global scale. For more information, see the [Ably documentation](https://ably.com/documentation)._
 
-This is a Ruby client library for Ably. The library currently targets the [Ably 1.2 client library specification](https://ably.com/documentation/client-lib-development-guide/features/). You can see the complete list of features this client library supports in [our client library SDKs feature support matrix](https://ably.com/download/sdk-feature-support-matrix).
+This is a Ruby client library for Ably. The library currently targets the [Ably 2.0.0 client library specification](https://ably.com/documentation/client-lib-development-guide/features/). You can see the complete list of features this client library supports in [our client library SDKs feature support matrix](https://ably.com/download/sdk-feature-support-matrix).
 
 ## Supported platforms
 
diff --git a/lib/ably/version.rb b/lib/ably/version.rb
index c0265f5c9..c0144ed69 100644
--- a/lib/ably/version.rb
+++ b/lib/ably/version.rb
@@ -1,9 +1,7 @@
 module Ably
   VERSION = '1.2.5'
-  PROTOCOL_VERSION = '1.2'
-
-  # @api private
-  def self.major_minor_version_numeric
-    VERSION.gsub(/\.\d+$/, '').to_f
-  end
+  # The level of compatibility with the Ably service that this SDK supports.
+  # Also referred to as the 'wire protocol version'.
+  # spec : CSV2
+  PROTOCOL_VERSION = '2'
 end
diff --git a/spec/acceptance/realtime/connection_spec.rb b/spec/acceptance/realtime/connection_spec.rb
index 6f01953e3..edfb8f702 100644
--- a/spec/acceptance/realtime/connection_spec.rb
+++ b/spec/acceptance/realtime/connection_spec.rb
@@ -2004,7 +2004,7 @@ def self.available_states
       it 'sends the protocol version param v (#G4, #RTN2f)' do
         expect(EventMachine).to receive(:connect) do |host, port, transport, object, url|
           uri = URI.parse(url)
-          expect(CGI::parse(uri.query)['v'][0]).to eql('1.2')
+          expect(CGI::parse(uri.query)['v'][0]).to eql('2')
           stop_reactor
         end
         client
diff --git a/spec/acceptance/rest/client_spec.rb b/spec/acceptance/rest/client_spec.rb
index db80bb65f..e1619c6ef 100644
--- a/spec/acceptance/rest/client_spec.rb
+++ b/spec/acceptance/rest/client_spec.rb
@@ -1095,9 +1095,16 @@ def encode64(text)
           end
 
           it 'sends a protocol version and lib version header (#G4, #RSC7a, #RSC7b)' do
-            client.channels.get('foo').publish("event")
+            response = client.channels.get('foo').publish("event")
+            expect(response).to eql true
             expect(publish_message_stub).to have_been_requested
-            expect(Ably::PROTOCOL_VERSION).to eql('1.2')
+            if agent.nil?
+              expect(publish_message_stub.to_s).to include("'Ably-Agent'=>'#{Ably::AGENT}'")
+              expect(publish_message_stub.to_s).to include("'X-Ably-Version'=>'2'")
+            else
+              expect(publish_message_stub.to_s).to include("'Ably-Agent'=>'ably-ruby/1.1.1 ruby/3.1.1'")
+              expect(publish_message_stub.to_s).to include("'X-Ably-Version'=>'2'")
+            end
           end
         end
       end

From 21279fa4706fdc2bdfabc00eb0421f9fcd4c4792 Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Thu, 6 Jun 2024 09:30:49 +0530
Subject: [PATCH 07/20] Renamed VERSION constant to LIB_VERSION for readability

---
 ably.gemspec                            | 2 +-
 lib/ably/agent.rb                       | 2 +-
 lib/ably/modules/http_helpers.rb        | 2 +-
 lib/ably/version.rb                     | 2 +-
 spec/support/markdown_spec_formatter.rb | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/ably.gemspec b/ably.gemspec
index d301cc808..9bbdc9435 100644
--- a/ably.gemspec
+++ b/ably.gemspec
@@ -5,7 +5,7 @@ require 'ably/version'
 
 Gem::Specification.new do |spec|
   spec.name          = 'ably'
-  spec.version       = Ably::VERSION
+  spec.version       = Ably::LIB_VERSION
   spec.authors       = ['Lewis Marshall', "Matthew O'Riordan"]
   spec.email         = ['lewis@lmars.net', 'matt@ably.io']
   spec.description   = %q{A Ruby client library for ably.io realtime messaging}
diff --git a/lib/ably/agent.rb b/lib/ably/agent.rb
index 39ea39e09..750027835 100644
--- a/lib/ably/agent.rb
+++ b/lib/ably/agent.rb
@@ -1,3 +1,3 @@
 module Ably
-  AGENT = "ably-ruby/#{Ably::VERSION} ruby/#{RUBY_VERSION}"
+  AGENT = "ably-ruby/#{Ably::LIB_VERSION} ruby/#{RUBY_VERSION}"
 end
diff --git a/lib/ably/modules/http_helpers.rb b/lib/ably/modules/http_helpers.rb
index 82a933b7b..6067d3440 100644
--- a/lib/ably/modules/http_helpers.rb
+++ b/lib/ably/modules/http_helpers.rb
@@ -18,7 +18,7 @@ def encode64(text)
     end
 
     def user_agent
-      "Ably Ruby client #{Ably::VERSION} (https://www.ably.io)"
+      "Ably Ruby client #{Ably::LIB_VERSION} (https://www.ably.io)"
     end
 
     def setup_outgoing_middleware(builder)
diff --git a/lib/ably/version.rb b/lib/ably/version.rb
index c0144ed69..743cede7b 100644
--- a/lib/ably/version.rb
+++ b/lib/ably/version.rb
@@ -1,5 +1,5 @@
 module Ably
-  VERSION = '1.2.5'
+  LIB_VERSION = '1.2.5'
   # The level of compatibility with the Ably service that this SDK supports.
   # Also referred to as the 'wire protocol version'.
   # spec : CSV2
diff --git a/spec/support/markdown_spec_formatter.rb b/spec/support/markdown_spec_formatter.rb
index ba4ca4f9b..40f62ec4b 100644
--- a/spec/support/markdown_spec_formatter.rb
+++ b/spec/support/markdown_spec_formatter.rb
@@ -28,7 +28,7 @@ def start(notification)
         else
           'REST'
         end
-        output.write "# Ably #{scope} Client Library #{Ably::VERSION} Specification\n"
+        output.write "# Ably #{scope} Client Library #{Ably::LIB_VERSION} Specification\n"
       end
 
       def close(notification)

From efb7dad42a37ebbf8593ea043136ee11f021362b Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Thu, 6 Jun 2024 09:34:18 +0530
Subject: [PATCH 08/20] Set idempotent rest publishing to true by default,
 updated relevant tests

---
 lib/ably/rest/client.rb              |  7 ++-----
 spec/acceptance/rest/message_spec.rb | 17 +++++++----------
 2 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/lib/ably/rest/client.rb b/lib/ably/rest/client.rb
index 235bd81f0..9f3348090 100644
--- a/lib/ably/rest/client.rb
+++ b/lib/ably/rest/client.rb
@@ -186,7 +186,7 @@ def initialize(options)
 
         @agent               = options.delete(:agent) || Ably::AGENT
         @realtime_client     = options.delete(:realtime_client)
-        @tls                 = options.delete(:tls) == false ? false : true
+        @tls                 = options.fetch(:tls, true); options.delete(:tls)
         @environment         = options.delete(:environment) # nil is production
         @environment         = nil if [:production, 'production'].include?(@environment)
         @protocol            = options.delete(:protocol) || :msgpack
@@ -200,10 +200,7 @@ def initialize(options)
         @log_retries_as_info = options.delete(:log_retries_as_info)
         @max_message_size    = options.delete(:max_message_size) || MAX_MESSAGE_SIZE
         @max_frame_size      = options.delete(:max_frame_size) || MAX_FRAME_SIZE
-
-        if (@idempotent_rest_publishing = options.delete(:idempotent_rest_publishing)).nil?
-          @idempotent_rest_publishing = Ably::PROTOCOL_VERSION.to_f > 1.1
-        end
+        @idempotent_rest_publishing = options.fetch(:idempotent_rest_publishing, true); options.delete(:idempotent_rest_publishing)
 
         if options[:fallback_hosts_use_default] && options[:fallback_hosts]
           raise ArgumentError, "fallback_hosts_use_default cannot be set to try when fallback_hosts is also provided"
diff --git a/spec/acceptance/rest/message_spec.rb b/spec/acceptance/rest/message_spec.rb
index 4291d6aa6..89ec72059 100644
--- a/spec/acceptance/rest/message_spec.rb
+++ b/spec/acceptance/rest/message_spec.rb
@@ -204,20 +204,17 @@
         end
       end
 
-      specify 'idempotent publishing is disabled by default with <= 1.1 (#TO3n)' do
-        stub_const 'Ably::PROTOCOL_VERSION', '1.0'
-        client = Ably::Rest::Client.new(key: api_key, protocol: protocol)
-        expect(client.idempotent_rest_publishing).to be_falsey
-        stub_const 'Ably::PROTOCOL_VERSION', '1.1'
-        client = Ably::Rest::Client.new(key: api_key, protocol: protocol)
+      specify 'idempotent publishing is set as per clientOptions' do
+        # set idempotent_rest_publishing to false
+        client = Ably::Rest::Client.new(key: api_key, protocol: protocol, idempotent_rest_publishing: false)
         expect(client.idempotent_rest_publishing).to be_falsey
+
+        # set idempotent_rest_publishing to true
+        client = Ably::Rest::Client.new(key: api_key, protocol: protocol, idempotent_rest_publishing: true)
+        expect(client.idempotent_rest_publishing).to be_truthy
       end
 
       specify 'idempotent publishing is enabled by default with >= 1.2 (#TO3n)' do
-        stub_const 'Ably::PROTOCOL_VERSION', '1.2'
-        client = Ably::Rest::Client.new(key: api_key, protocol: protocol)
-        expect(client.idempotent_rest_publishing).to be_truthy
-        stub_const 'Ably::PROTOCOL_VERSION', '1.3'
         client = Ably::Rest::Client.new(key: api_key, protocol: protocol)
         expect(client.idempotent_rest_publishing).to be_truthy
       end

From 4b448ff2ab5d3506000bc7088f09941cac595326 Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Thu, 6 Jun 2024 09:43:00 +0530
Subject: [PATCH 09/20] Added RecoveryKeyContext class and unit tests for the
 same

---
 .../realtime/recovery_key_context.rb          | 36 +++++++++++++++++++
 .../realtime/recovery_key_context_spec.rb     | 36 +++++++++++++++++++
 2 files changed, 72 insertions(+)
 create mode 100644 spec/acceptance/realtime/recovery_key_context.rb
 create mode 100644 spec/unit/realtime/recovery_key_context_spec.rb

diff --git a/spec/acceptance/realtime/recovery_key_context.rb b/spec/acceptance/realtime/recovery_key_context.rb
new file mode 100644
index 000000000..30ec3bc2e
--- /dev/null
+++ b/spec/acceptance/realtime/recovery_key_context.rb
@@ -0,0 +1,36 @@
+require 'json'
+# frozen_string_literal: true
+
+module Ably
+  module Realtime
+    class RecoveryKeyContext
+      attr_reader :connection_key
+      attr_reader :msg_serial
+      attr_reader :channel_serials
+
+      def initialize(connection_key, msg_serial, channel_serials)
+        @connection_key = connection_key
+        @msg_serial = msg_serial
+        @channel_serials = channel_serials
+        if @channel_serials.nil?
+          @channel_serials = {}
+        end
+      end
+
+      def to_json
+        { 'connection_key' => @connection_key, 'msg_serial' => @msg_serial, 'channel_serials' => @channel_serials }.to_json
+      end
+
+      def self.from_json(obj, logger = nil)
+        begin
+          data = JSON.load obj
+          self.new data['connection_key'], data['msg_serial'], data['channel_serials']
+        rescue => e
+          logger.warn "unable to decode recovery key, found error #{e}" unless logger.nil?
+          return nil
+        end
+      end
+
+    end
+  end
+end
diff --git a/spec/unit/realtime/recovery_key_context_spec.rb b/spec/unit/realtime/recovery_key_context_spec.rb
new file mode 100644
index 000000000..fd373a395
--- /dev/null
+++ b/spec/unit/realtime/recovery_key_context_spec.rb
@@ -0,0 +1,36 @@
+require 'spec_helper'
+require 'ably/realtime/recovery_key_context'
+
+describe Ably::Realtime::RecoveryKeyContext do
+
+  context 'connection recovery key' do
+
+    it 'should encode recovery key - RTN16i, RTN16f, RTN16j' do
+      connection_key = 'key'
+      msg_serial = 123
+      channel_serials = {
+        'channel1' => 'serial1',
+        'channel2' => 'serial2'
+      }
+      recovery_context = Ably::Realtime::RecoveryKeyContext.new(connection_key, msg_serial, channel_serials)
+      encoded_recovery_key = recovery_context.to_json
+      expect(encoded_recovery_key).to eq "{\"connection_key\":\"key\",\"msg_serial\":123," <<
+                                                "\"channel_serials\":{\"channel1\":\"serial1\",\"channel2\":\"serial2\"}}"
+    end
+
+    it 'should decode recovery key - RTN16i, RTN16f, RTN16j' do
+      encoded_recovery_key = "{\"connection_key\":\"key\",\"msg_serial\":123," <<
+                                     "\"channel_serials\":{\"channel1\":\"serial1\",\"channel2\":\"serial2\"}}"
+      decoded_recovery_key = Ably::Realtime::RecoveryKeyContext.from_json(encoded_recovery_key)
+      expect(decoded_recovery_key.connection_key).to eq("key")
+      expect(decoded_recovery_key.msg_serial).to eq(123)
+    end
+
+    it 'should return nil for invalid recovery key - RTN16i, RTN16f, RTN16j' do
+      encoded_recovery_key = "{\"invalid key\"}"
+      decoded_recovery_key = Ably::Realtime::RecoveryKeyContext.from_json(encoded_recovery_key)
+      expect(decoded_recovery_key).to be_nil
+    end
+
+  end
+end

From 7b8af6bbd478a675e915c9adf93c17aa504b26c3 Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Thu, 6 Jun 2024 10:05:24 +0530
Subject: [PATCH 10/20] Fixed typos in ruby docs for internal modules and
 realtime channel class

---
 lib/ably/modules/safe_deferrable.rb | 4 ++--
 lib/ably/modules/state_emitter.rb   | 2 +-
 lib/ably/realtime/channel.rb        | 2 +-
 lib/ably/util/safe_deferrable.rb    | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/ably/modules/safe_deferrable.rb b/lib/ably/modules/safe_deferrable.rb
index c011b4375..1849544db 100644
--- a/lib/ably/modules/safe_deferrable.rb
+++ b/lib/ably/modules/safe_deferrable.rb
@@ -39,7 +39,7 @@ def errback(&block)
       end
     end
 
-    # Mark the Deferrable as succeeded and trigger all callbacks.
+    # Mark the Deferrable as succeeded and trigger all success callbacks.
     # See http://www.rubydoc.info/gems/eventmachine/1.0.7/EventMachine/Deferrable#succeed-instance_method
     #
     # @return [void]
@@ -48,7 +48,7 @@ def succeed(*args)
       super(*args)
     end
 
-    # Mark the Deferrable as failed and trigger all callbacks.
+    # Mark the Deferrable as failed and trigger all error callbacks.
     # See http://www.rubydoc.info/gems/eventmachine/1.0.7/EventMachine/Deferrable#fail-instance_method
     #
     # @return [void]
diff --git a/lib/ably/modules/state_emitter.rb b/lib/ably/modules/state_emitter.rb
index c638cb9a4..2a5f8b516 100644
--- a/lib/ably/modules/state_emitter.rb
+++ b/lib/ably/modules/state_emitter.rb
@@ -3,7 +3,7 @@ module Ably::Modules
   # the instance variable @state is used exclusively, the {Enum} STATE is defined prior to inclusion of this
   # module, and the class is an {EventEmitter}.  It then emits state changes.
   #
-  # It also ensures the EventEmitter is configured to retrict permitted events to the
+  # It also ensures the EventEmitter is configured to restrict permitted events to the
   # the available STATEs or EVENTs if defined i.e. if EVENTs includes an additional type such as
   # :update, then it will support all EVENTs being emitted. EVENTs must be a superset of STATEs
   #
diff --git a/lib/ably/realtime/channel.rb b/lib/ably/realtime/channel.rb
index 6192cf666..162b153bf 100644
--- a/lib/ably/realtime/channel.rb
+++ b/lib/ably/realtime/channel.rb
@@ -42,7 +42,7 @@ class Channel
       #
       # @spec RTL2b
       #
-      # The permited states for this channel
+      # The permitted states for this channel
       STATE = ruby_enum('STATE',
         :initialized,
         :attaching,
diff --git a/lib/ably/util/safe_deferrable.rb b/lib/ably/util/safe_deferrable.rb
index 05b13c1cd..36cdd1cf8 100644
--- a/lib/ably/util/safe_deferrable.rb
+++ b/lib/ably/util/safe_deferrable.rb
@@ -1,6 +1,6 @@
 module Ably::Util
   # SafeDeferrable class provides a Deferrable that is safe to use for for public interfaces
-  # of this client library.  Any exceptions raised in the success or failure callbacks are
+  # of this client library. Any exceptions raised in the success or failure callbacks are
   # caught and logged to the provided logger.
   #
   # An exception in a callback provided by a developer should not break this client library

From a0114b9eb61d0368aeb78ad681ed60dcbe79def5 Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Thu, 6 Jun 2024 11:55:34 +0530
Subject: [PATCH 11/20] Added channelSerial field to channel properties,
 implemented following 1. Set channelSerial when message, presencemessage or
 attached received 2. Send channelSerial while sending channel attach message
 3. Set channelSerial to nil if channel is detached, failed or suspended

---
 lib/ably/models/protocol_message.rb              |  6 ++++++
 lib/ably/realtime/channel/channel_manager.rb     |  1 +
 lib/ably/realtime/channel/channel_properties.rb  |  9 +++++++++
 .../realtime/channel/channel_state_machine.rb    |  1 +
 .../client/incoming_message_dispatcher.rb        | 16 ++++++++++++++++
 5 files changed, 33 insertions(+)

diff --git a/lib/ably/models/protocol_message.rb b/lib/ably/models/protocol_message.rb
index fd4d98616..89cfddc0d 100644
--- a/lib/ably/models/protocol_message.rb
+++ b/lib/ably/models/protocol_message.rb
@@ -138,6 +138,12 @@ def has_message_serial?
       false
     end
 
+    def has_channel_serial?
+      channel_serial && true
+    rescue TypeError
+      false
+    end
+
     def messages
       @messages ||=
         Array(attributes[:messages]).map do |message|
diff --git a/lib/ably/realtime/channel/channel_manager.rb b/lib/ably/realtime/channel/channel_manager.rb
index 5b1761087..d10bc66ce 100644
--- a/lib/ably/realtime/channel/channel_manager.rb
+++ b/lib/ably/realtime/channel/channel_manager.rb
@@ -209,6 +209,7 @@ def send_attach_protocol_message
           message_options[:flags] = message_options[:flags].to_i | Ably::Models::ProtocolMessage::ATTACH_FLAGS_MAPPING[:resume]
         end
 
+        message_options[:channelSerial] = channel.properties.channel_serial # RTL4c1
         send_state_change_protocol_message Ably::Models::ProtocolMessage::ACTION.Attach, :suspended, message_options
       end
 
diff --git a/lib/ably/realtime/channel/channel_properties.rb b/lib/ably/realtime/channel/channel_properties.rb
index 26ddf2622..60f1911a8 100644
--- a/lib/ably/realtime/channel/channel_properties.rb
+++ b/lib/ably/realtime/channel/channel_properties.rb
@@ -18,6 +18,15 @@ class ChannelProperties
       #
       attr_reader :attach_serial
 
+      # ChannelSerial contains the channelSerial from latest ProtocolMessage of action type
+      # Message/PresenceMessage received on the channel.
+      #
+      # @spec CP2b, RTL15b
+      #
+      # @return [String]
+      #
+      attr_accessor :channel_serial
+
       def initialize(channel)
         @channel = channel
       end
diff --git a/lib/ably/realtime/channel/channel_state_machine.rb b/lib/ably/realtime/channel/channel_state_machine.rb
index fb91deee1..a346fec28 100644
--- a/lib/ably/realtime/channel/channel_state_machine.rb
+++ b/lib/ably/realtime/channel/channel_state_machine.rb
@@ -55,6 +55,7 @@ class ChannelStateMachine
       end
 
       after_transition(to: [:detached, :failed, :suspended]) do |channel, current_transition|
+        channel.properties.channel_serial = nil # RTP5a1
         err = error_from_state_change(current_transition)
         channel.manager.fail_queued_messages(err) if channel.failed? or channel.suspended? #RTL11
         channel.manager.log_channel_error err if err
diff --git a/lib/ably/realtime/client/incoming_message_dispatcher.rb b/lib/ably/realtime/client/incoming_message_dispatcher.rb
index 0b1057b14..821cb8705 100644
--- a/lib/ably/realtime/client/incoming_message_dispatcher.rb
+++ b/lib/ably/realtime/client/incoming_message_dispatcher.rb
@@ -38,6 +38,22 @@ def logger
 
       def dispatch_protocol_message(*args)
         protocol_message = args.first
+        # RTL15b
+        unless protocol_message.nil?
+          if protocol_message.has_channel_serial? &&
+                  (
+                    protocol_message.action == :message ||
+                    protocol_message.action == :presence ||
+                    protocol_message.action == :attached
+                  )
+
+            logger.info "Setting channel serial for #{channel.name}"
+            logger.info "Previous serial #{channel.name}, new serial #{protocol_message.channel_serial}"
+            get_channel(protocol_message.channel).tap do |channel|
+              channel.properties.channel_serial = protocol_message.channel_serial
+            end
+          end
+        end
 
         unless protocol_message.kind_of?(Ably::Models::ProtocolMessage)
           raise ArgumentError, "Expected a ProtocolMessage. Received #{protocol_message}"

From 4ba3917ac034168c0173f861853581a000a8135d Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Thu, 6 Jun 2024 13:10:33 +0530
Subject: [PATCH 12/20] Implemented create_recovery_key method on connection.
 Implemented 1. Retrieving value using create_recovery_key and setting
 msgserial, channel serials and recover key on connection 2. Handled
 resume/recover success/failure in connection manager. 3. Deprecated old
 recovery_key method on connection

---
 lib/ably/realtime/channels.rb                 | 20 ++++++++
 lib/ably/realtime/client.rb                   | 16 ++++--
 lib/ably/realtime/connection.rb               | 51 ++++++++++++++-----
 .../realtime/connection/connection_manager.rb | 34 ++++++-------
 lib/ably/util/string.rb                       |  9 ++++
 5 files changed, 97 insertions(+), 33 deletions(-)
 create mode 100644 lib/ably/util/string.rb

diff --git a/lib/ably/realtime/channels.rb b/lib/ably/realtime/channels.rb
index 9b814db12..1401f2d86 100644
--- a/lib/ably/realtime/channels.rb
+++ b/lib/ably/realtime/channels.rb
@@ -46,6 +46,26 @@ def release(channel)
           @channels.delete(channel)
         end if @channels.has_key?(channel)
       end
+
+      # Sets channel serial to each channel from given serials hashmap
+      # @param [Hash] serials - map of channel name to respective channel serial
+      # @api private
+      def set_channel_serials(serials)
+        serials.each do |channel_name, channel_serial|
+          channels[channel_name].properties.channel_serial = channel_serial
+        end
+      end
+
+      # @return [Hash] serials - map of channel name to respective channel serial
+      # @api private
+      def get_channel_serials
+        channel_serials = {}
+        self.each do |channel|
+          channel_serials[channel.name] = channel.properties.channel_serial if channel.state == :attached
+        end
+        channel_serials
+      end
+
     end
   end
 end
diff --git a/lib/ably/realtime/client.rb b/lib/ably/realtime/client.rb
index 16c243854..8c9248f58 100644
--- a/lib/ably/realtime/client.rb
+++ b/lib/ably/realtime/client.rb
@@ -120,15 +120,23 @@ def initialize(options)
           acc[key.to_s] = value.to_s
         end
         @rest_client           = Ably::Rest::Client.new(options.merge(realtime_client: self))
-        @echo_messages         = rest_client.options.fetch(:echo_messages, true) == false ? false : true
-        @queue_messages        = rest_client.options.fetch(:queue_messages, true) == false ? false : true
+        @echo_messages         = rest_client.options.fetch(:echo_messages, true)
+        @queue_messages        = rest_client.options.fetch(:queue_messages, true)
         @custom_realtime_host  = rest_client.options[:realtime_host] || rest_client.options[:ws_host]
-        @auto_connect          = rest_client.options.fetch(:auto_connect, true) == false ? false : true
-        @recover               = rest_client.options[:recover]
+        @auto_connect          = rest_client.options.fetch(:auto_connect, true)
+        @recover               = rest_client.options.fetch(:recover, '')
 
         @auth       = Ably::Realtime::Auth.new(self)
         @channels   = Ably::Realtime::Channels.new(self)
         @connection = Ably::Realtime::Connection.new(self, options)
+
+        unless @recover.empty?
+          recovery_context = RecoveryKeyContext.from_json(@recover, logger)
+          unless recovery_context.nil?
+            @channels.set_channel_serials recovery_context.channel_serials # RTN16j
+            @connection.set_msg_serial_from_recover = recovery_context.msg_serial  # RTN16f
+          end
+        end
       end
 
       # Return a {Ably::Realtime::Channel Realtime Channel} for the given name
diff --git a/lib/ably/realtime/connection.rb b/lib/ably/realtime/connection.rb
index a324d4865..bab01ed89 100644
--- a/lib/ably/realtime/connection.rb
+++ b/lib/ably/realtime/connection.rb
@@ -172,6 +172,8 @@ def initialize(client, options)
         @manager       = ConnectionManager.new(self)
 
         @current_host = client.endpoint.host
+
+        reset_client_msg_serial
       end
 
       # Causes the connection to close, entering the {Ably::Realtime::Connection::STATE} CLOSING state.
@@ -323,18 +325,35 @@ def internet_up?
         end
       end
 
-      # The recovery key string can be used by another client to recover this connection's state in the recover client options property. See connection state recover options for more information.
+      # The recovery key string can be used by another client to recover this connection's state in the
+      # recover client options property. See connection state recover options for more information.
       #
       # @spec RTN16b, RTN16c
       #
       # @return [String]
+      # @deprecated Use {#create_recovery_key} instead
       #
       def recovery_key
-        "will be implemented"
+        logger.warn "[DEPRECATION] recovery_key is deprecated, use create_recovery_key method instead"
+        create_recovery_key
       end
 
-      # Following a new connection being made, when connection key is sent
-      # connection id need to match with the details provided by the server.
+      # The recovery key string can be used by another client to recover this connection's state in the recover client
+      # options property. See connection state recover options for more information.
+      #
+      # @spec RTN16g, RTN16c
+      #
+      # @return [String] a json string which incorporates the @connectionKey@, the current @msgSerial@ and collection
+      # of pairs of channel @name@ and current @channelSerial@ for every currently attached channel
+      def create_recovery_key
+        if key.nil? || key.empty? || state == :closing || state == :closed || state == :failed || state == :suspended
+          return "" #RTN16g2
+        end
+        Ably::Modules::RecoveryKeyContext.to_json(key, message_serial, client.channels.get_channel_serials)
+      end
+
+      # Following a new connection being made, the connection ID, connection key
+      # need to match the details provided by the server.
       #
       # @return [void]
       # @api private
@@ -439,7 +458,7 @@ def create_websocket_transport
               url_params = auth_params.merge(
                 'format' =>     client.protocol,
                 'echo' =>       client.echo_messages,
-                'v' =>          Ably::PROTOCOL_VERSION,
+                'v' =>          Ably::PROTOCOL_VERSION, # RSC7a
                 'agent' =>      client.rest_client.agent
               )
 
@@ -453,13 +472,15 @@ def create_websocket_transport
               url_params['clientId'] = client.auth.client_id if client.auth.has_client_id?
               url_params.merge!(client.transport_params)
 
-              if connection_resumable?
-                puts "this is will be implemented as per spec"
-              elsif connection_recoverable?
-                puts "this is will be implemented as per spec"
-                logger.debug { "Recovering connection with key #{client.recover}" }
-                unsafe_once(:connected, :closed, :failed) do
-                  client.disable_automatic_connection_recovery
+              if not Ably::Util::String.is_null_or_empty(key)
+                url_params.merge! resume: key
+                logger.debug { "Resuming connection with key #{key}" }
+              elsif not Ably::Util::String.is_null_or_empty(client.recover)
+                recovery_context = RecoveryKeyContext.from_json(client.recover, logger)
+                unless recovery_context.nil?
+                  key = recovery_context.connection_key
+                  logger.debug { "Recovering connection with key #{key}" }
+                  url_params.merge! recover: key
                 end
               end
 
@@ -566,6 +587,12 @@ def reset_client_msg_serial
         @client_msg_serial = -1
       end
 
+      # Sets the client message serial from recover clientOption.
+      # @api private
+      def set_msg_serial_from_recover=(value)
+        @client_msg_serial = value
+      end
+
       # When a hearbeat or any other message from Ably is received
       # we know it's alive, see #RTN23
       # @api private
diff --git a/lib/ably/realtime/connection/connection_manager.rb b/lib/ably/realtime/connection/connection_manager.rb
index 9d5a95049..6cd1419b5 100644
--- a/lib/ably/realtime/connection/connection_manager.rb
+++ b/lib/ably/realtime/connection/connection_manager.rb
@@ -19,7 +19,8 @@ def initialize(connection)
         @connection     = connection
         @timers         = Hash.new { |hash, key| hash[key] = [] }
 
-        connection.unsafe_on(:closed) do
+        # RTN8c, RTN9c
+        connection.unsafe_on(:closing, :closed, :suspended, :failed) do
           connection.reset_resume_info
         end
 
@@ -111,23 +112,30 @@ def connected(protocol_message)
         # Update the connection details and any associated defaults
         connection.set_connection_details protocol_message.connection_details
 
+        is_connection_resume_or_recover_attempt = !Ably::Util::String.is_null_or_empty(connection.key) ||
+          !Ably::Util::String.is_null_or_empty(client.recover)
+
+        # RTN15c7, RTN16d
+        failed_resume_or_recover = !protocol_message.connection_id == connection.id && !protocol_message.error.nil?
+        if is_connection_resume_or_recover_attempt and failed_resume_or_recover # RTN15c7
+          connection.reset_client_msg_serial
+        end
+        client.disable_automatic_connection_recovery # RTN16k, explicitly setting null, so it won't be used for subsequent connection requests
+
         if connection.key
           if protocol_message.connection_id == connection.id
             logger.debug { "ConnectionManager: Connection resumed successfully - ID #{connection.id} and key #{connection.key}" }
             EventMachine.next_tick { connection.trigger_resumed }
             resend_pending_message_ack_queue
           else
-            logger.debug { "ConnectionManager: Connection was not resumed, old connection ID #{connection.id} has been updated with new connection ID #{protocol_message.connection_id} and key #{protocol_message.connection_details.connection_key}" }
             nack_messages_on_all_channels protocol_message.error
-            force_reattach_on_channels protocol_message.error
           end
         else
           logger.debug { "ConnectionManager: New connection created with ID #{protocol_message.connection_id} and key #{protocol_message.connection_details.connection_key}" }
         end
 
-        reattach_suspended_channels protocol_message.error
-
         connection.configure_new protocol_message.connection_id, protocol_message.connection_details.connection_key
+        force_reattach_on_channels protocol_message.error # irrespective of connection success/failure, reattach channels
       end
 
       # When connection is CONNECTED and receives an update
@@ -568,20 +576,12 @@ def currently_renewing_token?
         client.auth.authorization_in_flight?
       end
 
-      def reattach_suspended_channels(error)
-        channels.select do |channel|
-          channel.suspended?
-        end.each do |channel|
-          channel.transition_state_machine :attaching
-        end
-      end
-
-      # When continuity on a connection is lost all messages
-      # Channels in the ATTACHED or ATTACHING state should explicitly be re-attached
-      # by sending a new ATTACH to Ably
+      # When reconnected if channel is in ATTACHING, ATTACHED or SUSPENDED state
+      # it should explicitly be re-attached by sending a new ATTACH to Ably
+      # Spec : RTN15c6, RTN15c7
       def force_reattach_on_channels(error)
         channels.select do |channel|
-          channel.attached? || channel.attaching?
+          channel.attached? || channel.attaching? || channel.suspended?
         end.each do |channel|
           channel.manager.request_reattach reason: error
         end
diff --git a/lib/ably/util/string.rb b/lib/ably/util/string.rb
new file mode 100644
index 000000000..3a8b0888f
--- /dev/null
+++ b/lib/ably/util/string.rb
@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+module Ably::Util
+    module String
+        def self.is_null_or_empty(str)
+        str.nil? || str.empty?
+        end
+    end
+end

From c0760d6b0d6e3dd78704e0c06a6c6a8942ccdfdc Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Thu, 6 Jun 2024 13:25:08 +0530
Subject: [PATCH 13/20] Fix file location: Moved recovery_key_context from test
 to lib

---
 {spec/acceptance => lib/ably}/realtime/recovery_key_context.rb | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename {spec/acceptance => lib/ably}/realtime/recovery_key_context.rb (100%)

diff --git a/spec/acceptance/realtime/recovery_key_context.rb b/lib/ably/realtime/recovery_key_context.rb
similarity index 100%
rename from spec/acceptance/realtime/recovery_key_context.rb
rename to lib/ably/realtime/recovery_key_context.rb

From b0ad4fb07f417c1c668daf05a7be495dd586d79b Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Fri, 21 Jun 2024 10:40:40 +0530
Subject: [PATCH 14/20] Revert "Renamed VERSION constant to LIB_VERSION for
 readability"

This reverts commit 21279fa4706fdc2bdfabc00eb0421f9fcd4c4792.
---
 ably.gemspec                            | 2 +-
 lib/ably/agent.rb                       | 2 +-
 lib/ably/modules/http_helpers.rb        | 2 +-
 lib/ably/version.rb                     | 2 +-
 spec/support/markdown_spec_formatter.rb | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/ably.gemspec b/ably.gemspec
index 9bbdc9435..d301cc808 100644
--- a/ably.gemspec
+++ b/ably.gemspec
@@ -5,7 +5,7 @@ require 'ably/version'
 
 Gem::Specification.new do |spec|
   spec.name          = 'ably'
-  spec.version       = Ably::LIB_VERSION
+  spec.version       = Ably::VERSION
   spec.authors       = ['Lewis Marshall', "Matthew O'Riordan"]
   spec.email         = ['lewis@lmars.net', 'matt@ably.io']
   spec.description   = %q{A Ruby client library for ably.io realtime messaging}
diff --git a/lib/ably/agent.rb b/lib/ably/agent.rb
index 750027835..39ea39e09 100644
--- a/lib/ably/agent.rb
+++ b/lib/ably/agent.rb
@@ -1,3 +1,3 @@
 module Ably
-  AGENT = "ably-ruby/#{Ably::LIB_VERSION} ruby/#{RUBY_VERSION}"
+  AGENT = "ably-ruby/#{Ably::VERSION} ruby/#{RUBY_VERSION}"
 end
diff --git a/lib/ably/modules/http_helpers.rb b/lib/ably/modules/http_helpers.rb
index 6067d3440..82a933b7b 100644
--- a/lib/ably/modules/http_helpers.rb
+++ b/lib/ably/modules/http_helpers.rb
@@ -18,7 +18,7 @@ def encode64(text)
     end
 
     def user_agent
-      "Ably Ruby client #{Ably::LIB_VERSION} (https://www.ably.io)"
+      "Ably Ruby client #{Ably::VERSION} (https://www.ably.io)"
     end
 
     def setup_outgoing_middleware(builder)
diff --git a/lib/ably/version.rb b/lib/ably/version.rb
index 743cede7b..c0144ed69 100644
--- a/lib/ably/version.rb
+++ b/lib/ably/version.rb
@@ -1,5 +1,5 @@
 module Ably
-  LIB_VERSION = '1.2.5'
+  VERSION = '1.2.5'
   # The level of compatibility with the Ably service that this SDK supports.
   # Also referred to as the 'wire protocol version'.
   # spec : CSV2
diff --git a/spec/support/markdown_spec_formatter.rb b/spec/support/markdown_spec_formatter.rb
index 40f62ec4b..ba4ca4f9b 100644
--- a/spec/support/markdown_spec_formatter.rb
+++ b/spec/support/markdown_spec_formatter.rb
@@ -28,7 +28,7 @@ def start(notification)
         else
           'REST'
         end
-        output.write "# Ably #{scope} Client Library #{Ably::LIB_VERSION} Specification\n"
+        output.write "# Ably #{scope} Client Library #{Ably::VERSION} Specification\n"
       end
 
       def close(notification)

From c4ff9e55e206b46819e2da3ead30afba95f38045 Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Fri, 21 Jun 2024 10:51:50 +0530
Subject: [PATCH 15/20] Refactored idempotent publishing test name to be
 enabled by default

---
 spec/acceptance/rest/message_spec.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/spec/acceptance/rest/message_spec.rb b/spec/acceptance/rest/message_spec.rb
index 89ec72059..49960226e 100644
--- a/spec/acceptance/rest/message_spec.rb
+++ b/spec/acceptance/rest/message_spec.rb
@@ -214,7 +214,7 @@
         expect(client.idempotent_rest_publishing).to be_truthy
       end
 
-      specify 'idempotent publishing is enabled by default with >= 1.2 (#TO3n)' do
+      specify 'idempotent publishing is enabled by default (#TO3n)' do
         client = Ably::Rest::Client.new(key: api_key, protocol: protocol)
         expect(client.idempotent_rest_publishing).to be_truthy
       end

From b1789fa1c0acf2f5b2e4fd58f015a3a9132e77e1 Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Fri, 21 Jun 2024 13:05:05 +0530
Subject: [PATCH 16/20] removed nil check for protocol_message while setting
 channel serial

---
 .../client/incoming_message_dispatcher.rb     | 30 +++++++++----------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/lib/ably/realtime/client/incoming_message_dispatcher.rb b/lib/ably/realtime/client/incoming_message_dispatcher.rb
index 821cb8705..435d70660 100644
--- a/lib/ably/realtime/client/incoming_message_dispatcher.rb
+++ b/lib/ably/realtime/client/incoming_message_dispatcher.rb
@@ -38,27 +38,25 @@ def logger
 
       def dispatch_protocol_message(*args)
         protocol_message = args.first
-        # RTL15b
-        unless protocol_message.nil?
-          if protocol_message.has_channel_serial? &&
-                  (
-                    protocol_message.action == :message ||
-                    protocol_message.action == :presence ||
-                    protocol_message.action == :attached
-                  )
-
-            logger.info "Setting channel serial for #{channel.name}"
-            logger.info "Previous serial #{channel.name}, new serial #{protocol_message.channel_serial}"
-            get_channel(protocol_message.channel).tap do |channel|
-              channel.properties.channel_serial = protocol_message.channel_serial
-            end
-          end
-        end
 
         unless protocol_message.kind_of?(Ably::Models::ProtocolMessage)
           raise ArgumentError, "Expected a ProtocolMessage. Received #{protocol_message}"
         end
 
+        # RTL15b
+        if protocol_message.has_channel_serial? &&
+          (
+            protocol_message.action == :message ||
+              protocol_message.action == :presence ||
+              protocol_message.action == :attached
+          )
+          get_channel(protocol_message.channel).tap do |channel|
+            logger.info "Setting channel serial for channel #{channel.name}, " <<
+                          "Previous: #{channel.properties.channel_serial}, New: #{protocol_message.channel_serial}"
+            channel.properties.channel_serial = protocol_message.channel_serial
+          end
+        end
+
         unless protocol_message.action.match_any?(:nack, :error)
           logger.debug { "#{protocol_message.action} received: #{protocol_message}" }
         end

From 54e186d121ebcc529506a4afc77c138a5ee47310 Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Fri, 21 Jun 2024 13:07:03 +0530
Subject: [PATCH 17/20] channel_name accessor made explicit for better
 readability

---
 lib/ably/realtime/channels.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/ably/realtime/channels.rb b/lib/ably/realtime/channels.rb
index 1401f2d86..e7cf788dd 100644
--- a/lib/ably/realtime/channels.rb
+++ b/lib/ably/realtime/channels.rb
@@ -52,7 +52,7 @@ def release(channel)
       # @api private
       def set_channel_serials(serials)
         serials.each do |channel_name, channel_serial|
-          channels[channel_name].properties.channel_serial = channel_serial
+          get(channel_name).properties.channel_serial = channel_serial
         end
       end
 

From 15b21d734fae9304e499c71a429db44aeccf2528 Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Fri, 21 Jun 2024 13:07:34 +0530
Subject: [PATCH 18/20] returning nil for create_recovery_key, same as old
 deprecated recovery_key method

---
 lib/ably/realtime/connection.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/ably/realtime/connection.rb b/lib/ably/realtime/connection.rb
index bab01ed89..466c877ed 100644
--- a/lib/ably/realtime/connection.rb
+++ b/lib/ably/realtime/connection.rb
@@ -347,7 +347,7 @@ def recovery_key
       # of pairs of channel @name@ and current @channelSerial@ for every currently attached channel
       def create_recovery_key
         if key.nil? || key.empty? || state == :closing || state == :closed || state == :failed || state == :suspended
-          return "" #RTN16g2
+          return nil #RTN16g2
         end
         Ably::Modules::RecoveryKeyContext.to_json(key, message_serial, client.channels.get_channel_serials)
       end

From 32e68cff868fd18f2d16ec8b0b012ca32626244d Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Mon, 24 Jun 2024 15:17:09 +0530
Subject: [PATCH 19/20] Added AblyExtensions for empty/nil string check,
 updated usages for the same at all places

---
 lib/ably/realtime/client.rb                   | 12 ++++----
 lib/ably/realtime/connection.rb               | 12 ++++----
 .../realtime/connection/connection_manager.rb |  4 +--
 lib/ably/rest/client.rb                       |  5 ++--
 lib/ably/util/ably_extensions.rb              | 29 +++++++++++++++++++
 lib/ably/util/string.rb                       |  9 ------
 6 files changed, 48 insertions(+), 23 deletions(-)
 create mode 100644 lib/ably/util/ably_extensions.rb
 delete mode 100644 lib/ably/util/string.rb

diff --git a/lib/ably/realtime/client.rb b/lib/ably/realtime/client.rb
index 8c9248f58..b35aaa94b 100644
--- a/lib/ably/realtime/client.rb
+++ b/lib/ably/realtime/client.rb
@@ -1,5 +1,6 @@
 require 'uri'
 require 'ably/realtime/channel/publisher'
+require 'ably/realtime/recovery_key_context'
 
 module Ably
   module Realtime
@@ -11,6 +12,7 @@ class Client
       include Ably::Modules::Conversions
 
       extend Forwardable
+      using Ably::Util::AblyExtensions
 
       DOMAIN = 'realtime.ably.io'
 
@@ -120,17 +122,17 @@ def initialize(options)
           acc[key.to_s] = value.to_s
         end
         @rest_client           = Ably::Rest::Client.new(options.merge(realtime_client: self))
-        @echo_messages         = rest_client.options.fetch(:echo_messages, true)
-        @queue_messages        = rest_client.options.fetch(:queue_messages, true)
+        @echo_messages         = rest_client.options.fetch_with_default(:echo_messages, true)
+        @queue_messages        = rest_client.options.fetch_with_default(:queue_messages, true)
         @custom_realtime_host  = rest_client.options[:realtime_host] || rest_client.options[:ws_host]
-        @auto_connect          = rest_client.options.fetch(:auto_connect, true)
-        @recover               = rest_client.options.fetch(:recover, '')
+        @auto_connect          = rest_client.options.fetch_with_default(:auto_connect, true)
+        @recover               = rest_client.options.fetch_with_default(:recover, '')
 
         @auth       = Ably::Realtime::Auth.new(self)
         @channels   = Ably::Realtime::Channels.new(self)
         @connection = Ably::Realtime::Connection.new(self, options)
 
-        unless @recover.empty?
+        unless @recover.nil_or_empty?
           recovery_context = RecoveryKeyContext.from_json(@recover, logger)
           unless recovery_context.nil?
             @channels.set_channel_serials recovery_context.channel_serials # RTN16j
diff --git a/lib/ably/realtime/connection.rb b/lib/ably/realtime/connection.rb
index 466c877ed..aa0f1ada2 100644
--- a/lib/ably/realtime/connection.rb
+++ b/lib/ably/realtime/connection.rb
@@ -9,6 +9,8 @@ class Connection
       include Ably::Modules::Conversions
       include Ably::Modules::SafeYield
       extend Ably::Modules::Enum
+      using Ably::Util::AblyExtensions
+
 
       # The current {Ably::Realtime::Connection::STATE} of the connection.
       # Describes the realtime [Connection]{@link Connection} object states.
@@ -330,7 +332,6 @@ def internet_up?
       #
       # @spec RTN16b, RTN16c
       #
-      # @return [String]
       # @deprecated Use {#create_recovery_key} instead
       #
       def recovery_key
@@ -346,10 +347,10 @@ def recovery_key
       # @return [String] a json string which incorporates the @connectionKey@, the current @msgSerial@ and collection
       # of pairs of channel @name@ and current @channelSerial@ for every currently attached channel
       def create_recovery_key
-        if key.nil? || key.empty? || state == :closing || state == :closed || state == :failed || state == :suspended
+        if key.nil_or_empty? || state == :closing || state == :closed || state == :failed || state == :suspended
           return nil #RTN16g2
         end
-        Ably::Modules::RecoveryKeyContext.to_json(key, message_serial, client.channels.get_channel_serials)
+        RecoveryKeyContext.new(key, client_msg_serial, client.channels.get_channel_serials).to_json
       end
 
       # Following a new connection being made, the connection ID, connection key
@@ -472,10 +473,10 @@ def create_websocket_transport
               url_params['clientId'] = client.auth.client_id if client.auth.has_client_id?
               url_params.merge!(client.transport_params)
 
-              if not Ably::Util::String.is_null_or_empty(key)
+              if !key.nil_or_empty? and connection_state_available?
                 url_params.merge! resume: key
                 logger.debug { "Resuming connection with key #{key}" }
-              elsif not Ably::Util::String.is_null_or_empty(client.recover)
+              elsif !client.recover.nil_or_empty?
                 recovery_context = RecoveryKeyContext.from_json(client.recover, logger)
                 unless recovery_context.nil?
                   key = recovery_context.connection_key
@@ -717,3 +718,4 @@ def second_reconnect_attempt_for(state, first_attempt_count)
 require 'ably/realtime/connection/connection_manager'
 require 'ably/realtime/connection/connection_state_machine'
 require 'ably/realtime/connection/websocket_transport'
+require 'ably/realtime/recovery_key_context'
diff --git a/lib/ably/realtime/connection/connection_manager.rb b/lib/ably/realtime/connection/connection_manager.rb
index 6cd1419b5..cfbfe87d1 100644
--- a/lib/ably/realtime/connection/connection_manager.rb
+++ b/lib/ably/realtime/connection/connection_manager.rb
@@ -14,6 +14,7 @@ class ConnectionManager
       RESOLVABLE_ERROR_CODES = {
         token_expired: Ably::Exceptions::TOKEN_EXPIRED_CODE
       }
+      using Ably::Util::AblyExtensions
 
       def initialize(connection)
         @connection     = connection
@@ -112,8 +113,7 @@ def connected(protocol_message)
         # Update the connection details and any associated defaults
         connection.set_connection_details protocol_message.connection_details
 
-        is_connection_resume_or_recover_attempt = !Ably::Util::String.is_null_or_empty(connection.key) ||
-          !Ably::Util::String.is_null_or_empty(client.recover)
+        is_connection_resume_or_recover_attempt = !connection.key.nil_or_empty? || !client.recover.nil_or_empty?
 
         # RTN15c7, RTN16d
         failed_resume_or_recover = !protocol_message.connection_id == connection.id && !protocol_message.error.nil?
diff --git a/lib/ably/rest/client.rb b/lib/ably/rest/client.rb
index 9f3348090..7aa34e3cb 100644
--- a/lib/ably/rest/client.rb
+++ b/lib/ably/rest/client.rb
@@ -16,6 +16,7 @@ class Client
       include Ably::Modules::Conversions
       include Ably::Modules::HttpHelpers
       extend Forwardable
+      using Ably::Util::AblyExtensions
 
       # Default Ably domain for REST
       DOMAIN = 'rest.ably.io'
@@ -186,7 +187,7 @@ def initialize(options)
 
         @agent               = options.delete(:agent) || Ably::AGENT
         @realtime_client     = options.delete(:realtime_client)
-        @tls                 = options.fetch(:tls, true); options.delete(:tls)
+        @tls                 = options.delete_with_default(:tls, true)
         @environment         = options.delete(:environment) # nil is production
         @environment         = nil if [:production, 'production'].include?(@environment)
         @protocol            = options.delete(:protocol) || :msgpack
@@ -200,7 +201,7 @@ def initialize(options)
         @log_retries_as_info = options.delete(:log_retries_as_info)
         @max_message_size    = options.delete(:max_message_size) || MAX_MESSAGE_SIZE
         @max_frame_size      = options.delete(:max_frame_size) || MAX_FRAME_SIZE
-        @idempotent_rest_publishing = options.fetch(:idempotent_rest_publishing, true); options.delete(:idempotent_rest_publishing)
+        @idempotent_rest_publishing = options.delete_with_default(:idempotent_rest_publishing, true)
 
         if options[:fallback_hosts_use_default] && options[:fallback_hosts]
           raise ArgumentError, "fallback_hosts_use_default cannot be set to try when fallback_hosts is also provided"
diff --git a/lib/ably/util/ably_extensions.rb b/lib/ably/util/ably_extensions.rb
new file mode 100644
index 000000000..c4304eb8a
--- /dev/null
+++ b/lib/ably/util/ably_extensions.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+module Ably::Util
+  module AblyExtensions
+    refine Object do
+      def nil_or_empty?
+        self.nil? || self.empty?
+      end
+    end
+
+    refine Hash do
+      def fetch_with_default(key, default)
+        value = self.fetch(key, default)
+        if value.nil?
+          return default
+        end
+        return value
+      end
+
+      def delete_with_default(key, default)
+        value = self.delete(key)
+        if value.nil?
+          return default
+        end
+        return value
+      end
+    end
+  end
+end
diff --git a/lib/ably/util/string.rb b/lib/ably/util/string.rb
deleted file mode 100644
index 3a8b0888f..000000000
--- a/lib/ably/util/string.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-# frozen_string_literal: true
-
-module Ably::Util
-    module String
-        def self.is_null_or_empty(str)
-        str.nil? || str.empty?
-        end
-    end
-end

From 7a04abc9fe4ee1d7dfadb759fddabf9f8117ca02 Mon Sep 17 00:00:00 2001
From: sacOO7 <sachinshinde7676@gmail.com>
Date: Mon, 24 Jun 2024 15:19:05 +0530
Subject: [PATCH 20/20] Updated invalid check impl on protocol_message received

---
 lib/ably/models/protocol_message.rb | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/ably/models/protocol_message.rb b/lib/ably/models/protocol_message.rb
index 89cfddc0d..0088fded7 100644
--- a/lib/ably/models/protocol_message.rb
+++ b/lib/ably/models/protocol_message.rb
@@ -274,11 +274,12 @@ def to_s
     end
 
     # True if the ProtocolMessage appears to be invalid, however this is not a guarantee
+    # Used for validating incoming protocol messages, so no need to add unnecessary checks
     # @return [Boolean]
     # @api private
     def invalid?
       action_enum = action rescue nil
-      !action_enum || (ack_required? && !has_message_serial?)
+      !action_enum
     end
 
     # @!attribute [r] logger