Make Message a regular class instead of a Struct

lib/message_bus/message.rb

@@ -1,8 +1,16 @@
 # frozen_string_literal: true
 
 # Represents a published message and its encoding for persistence.
-class MessageBus::Message < Struct.new(:global_id, :message_id, :channel, :data)
-  attr_accessor :site_id, :user_ids, :group_ids, :client_ids
+class MessageBus::Message
+  attr_accessor :global_id, :message_id, :channel, :data,
+                :site_id, :user_ids, :group_ids, :client_ids
+
+  def initialize(global_id, message_id, channel, data)
+    @global_id = global_id
+    @message_id = message_id
+    @channel = channel
+    @data = data
+  end
 
   def self.decode(encoded)
     s1 = encoded.index("|")
@@ -15,7 +23,7 @@ def self.decode(encoded)
     channel.gsub!("$$123$$", "|")
     data = encoded[(s3 + 1), encoded.size]
 
-    MessageBus::Message.new(global_id, message_id, channel, data)
+    new(global_id, message_id, channel, data)
   end
 
   # only tricky thing to encode is pipes in a channel name ... do a straight replace
@@ -26,4 +34,12 @@ def encode
   def encode_without_ids
     "#{channel.gsub("|", "$$123$$")}|#{data}"
   end
+
+  def ==(other)
+    other.is_a?(self.class) &&
+      self.global_id == other.global_id &&
+      self.message_id == other.message_id &&
+      self.channel == other.channel &&
+      self.data == other.data
+  end
 end