Fix the failing test and make sure the old test still works

Author: klippx

lib/kafka/protocol/message.rb

@@ -56,20 +56,7 @@ def decompress
         # For some weird reason we need to cut out the first 20 bytes.
         data = codec.decompress(value)
         message_set_decoder = Decoder.from_string(data)
-        message_set = MessageSet.decode(message_set_decoder)
-
-        # The contained messages need to have their offset corrected.
-        messages = message_set.messages.each_with_index.map do |message, i|
-          Message.new(
-            offset: offset + i,
-            value: message.value,
-            key: message.key,
-            create_time: message.create_time,
-            codec_id: message.codec_id
-          )
-        end
-
-        MessageSet.new(messages: messages)
+        MessageSet.decode(message_set_decoder)
       end
 
       def self.decode(decoder)

spec/compressor_spec.rb

@@ -5,8 +5,8 @@
     it "encodes and decodes compressed messages" do
       compressor = Kafka::Compressor.new(codec_name: :snappy, threshold: 1, instrumenter: instrumenter)
 
-      message1 = Kafka::Protocol::Message.new(value: "hello1")
-      message2 = Kafka::Protocol::Message.new(value: "hello2")
+      message1 = Kafka::Protocol::Message.new(value: "hello1", offset: -1)
+      message2 = Kafka::Protocol::Message.new(value: "hello2", offset: 0)
 
       message_set = Kafka::Protocol::MessageSet.new(messages: [message1, message2])
       compressed_message_set = compressor.compress(message_set)