Message id access

.gitignore

@@ -6,4 +6,5 @@
 /doc/
 /pkg/
 /spec/reports/
+/spec/examples.txt
 /tmp/

.ruby-version

@@ -0,0 +1 @@
+2.5.0

.travis.yml

@@ -1,6 +1,5 @@
 language: ruby
 rvm:
-  - 2.1.9
-  - 2.2.5
-  - 2.3.1
+  - 2.4.1
+  - 2.5.0
 before_install: gem update bundler

CHANGELOG.md

@@ -0,0 +1,10 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+### Added
+- Ability to specify `last_id` of a channel
+- Get access to `message_id` if specified in the callback

Gemfile

@@ -2,3 +2,5 @@ source 'https://rubygems.org'
 
 # Specify your gem's dependencies in message_bus-client.gemspec
 gemspec
+
+gem "pry-byebug"

README.md

@@ -26,7 +26,7 @@ The API is mostly equivalent with the JavaScript client:
 
 ```ruby
 client = MessageBus::Client.new('http://chat.samsaffron.com/')
-client.subscribe('/message') do |payload|
+client.subscribe('/message') do |payload, message_id|
   # Do stuff
 end
 

Rakefile

@@ -11,9 +11,18 @@ task :server do
   end
 
   at_exit do
-    $stderr.puts "Killing pid #{pid}"
-    Process.kill('KILL', pid)
-    Process.wait(pid)
+    if RbConfig::CONFIG["host_os"] =~ /mswin|mingw/
+      $stderr.puts "Killing pid #{pid}"
+      Process.kill('KILL', pid)
+      Process.wait(pid)
+    else
+      child_pid = `pgrep -P #{pid}`.to_i
+      pids = [child_pid, pid]
+      pids.each do |pid|
+        $stderr.puts "Killing pid #{pid}"
+        Process.kill('KILL', pid)
+      end
+    end
   end
 
   sleep 3

lib/message_bus/client.rb

@@ -1,5 +1,6 @@
 require 'excon'
 require 'json'
+require "securerandom"
 
 require 'message_bus/client/version'
 require 'message_bus/client/configuration'

lib/message_bus/client/message_handler.rb

@@ -1,13 +1,13 @@
 module MessageBus::Client::MessageHandler
   SubscribedChannel = Struct.new(:callbacks, :last_id) do
-    def initialize(last_id = -1)
+    def initialize(last_id)
       self.callbacks = []
       self.last_id = last_id
     end
 
-    def callback(payload)
+    def callback(payload, message_id)
       callbacks.each do |callback|
-        callback.call(payload)
+        callback.call(payload, message_id)
       end
     end
   end
@@ -20,14 +20,16 @@ def initialize(base_url)
 
     @pending_messages = []
     @subscribed_channels = {}
-    @subscribed_channels.default_proc = proc do |hash, key|
-      hash[key] = SubscribedChannel.new
-    end
     @payload = String.new
   end
 
-  def subscribe(channel, &callback)
-    @subscribed_channels[channel].callbacks << callback
+  def subscribe(channel, last_id=-1, &callback)
+    subscribed_channel = @subscribed_channels[channel]
+    if subscribed_channel.nil?
+      subscribed_channel = @subscribed_channels[channel] =
+        SubscribedChannel.new(last_id)
+    end
+    subscribed_channel.callbacks << callback
   end
 
   def unsubscribe
@@ -80,8 +82,9 @@ def handle_message(message)
     subscription = @subscribed_channels[message['channel']]
     return unless subscription
 
-    subscription.last_id = message['message_id']
-    subscription.callback(message['data'])
+    message_id = message['message_id']
+    subscription.last_id = message_id
+    subscription.callback(message['data'], message_id)
   end
 
   def handle_status_message(message)

spec/message_bus/client_spec.rb

@@ -37,7 +37,7 @@ def write_message(message, user = 'message_bus-client')
       end
     end
 
-    it 'receives messages' do
+    it 'receives new messages by default (last_id of -1)' do
       subject.start
 
       text = "Hello World! #{Random.rand}"
@@ -72,7 +72,7 @@ def write_message(message, user = 'message_bus-client')
       subject.stop
     end
 
-    it 'receives messages' do
+    it 'receives new messages by default (last_id of -1)' do
       subject.start
 
       text = "Hello World! #{Random.rand}"
@@ -113,4 +113,20 @@ def write_message(message, user = 'message_bus-client')
     subject.resume
     expect(result).to eq(true)
   end
+
+  it 'allows subscription exposing the message_id' do
+    subject.start
+
+    text = "Hello World! #{Random.rand}"
+    result = false
+    subject.subscribe('/message') do |payload, message_id|
+      result = true if payload['data'] == text
+      expect(message_id).to be_an Integer
+    end
+
+    until result
+      write_message(text) # Keep writing because the message bus might not have started.
+      sleep(1)
+    end
+  end
 end

spec/spec_helper.rb

@@ -1,6 +1,6 @@
 $LOAD_PATH.unshift File.expand_path('../../lib', __FILE__)
-require 'coverage_helper'
 require 'message_bus/client'
+require "pry-byebug"
 
 # This file was generated by the `rspec --init` command. Conventionally, all
 # specs live under a `spec` directory, which RSpec adds to the `$LOAD_PATH`.