Use custom fake message to mock value to be a 'json' string

lib/fake/kafka.rb

@@ -1,12 +1,10 @@
 require 'fake/kafka/version'
 require 'fake/kafka/consumer'
 require 'fake/kafka/producer'
-#require 'fake/kafka/message'
+require 'fake/kafka/message'
 
 module Fake
   class Kafka
-    FakeMessage = Struct.new(:value, :key, :topic, :partition, :offset)
-    # Your code goes here...
     attr_reader :messages, :paused_partitions
 
     def initialize(*options)
@@ -20,7 +18,7 @@ def paused?(topic, partition)
     end
 
     def deliver_message(value, topic:)
-      @messages << FakeMessage.new(value, nil, topic, 0, 0)
+      @messages << Message.new(value, nil, topic, 0, 0)
     end
 
     def messages_in(topic)

lib/fake/kafka/message.rb

@@ -0,0 +1,14 @@
+class Fake::Kafka::Message
+  attr_reader :key, :topic, :partition, :offset
+  def initialize(value, key, topic, partition, offset)
+    @value = value
+    @key = key
+    @topic = topic
+    @partition = partition
+    @offset = offset
+  end
+
+  def value
+    @value.to_json
+  end
+end