Repair outputs/file test + add use of zcat command to cover LOGSTASH-997

spec/outputs/file.rb

@@ -29,7 +29,7 @@
       # Now check all events for order and correctness.
       File.foreach(tmp_file) do |line|
         event = LogStash::Event.from_json(line)
-        insist {event.message} == "hello world"
+        insist {event["message"]} == "hello world"
         insist {event["sequence"]} == line_num
         line_num += 1
       end
@@ -62,7 +62,17 @@
       # Now check all events for order and correctness.
       Zlib::GzipReader.new(File.open(tmp_file)).each_line do |line|
         event = LogStash::Event.from_json(line)
-        insist {event.message} == "hello world"
+        insist {event["message"]} == "hello world"
+        insist {event["sequence"]} == line_num
+        line_num += 1
+      end
+      insist {line_num} == event_count
+
+      #LOGSTASH-997 confirm usage of zcat command on file
+      line_num = 0
+      `zcat #{tmp_file.path()}`.split("\n").each do |line|
+        event = LogStash::Event.from_json(line)
+        insist {event["message"]} == "hello world"
         insist {event["sequence"]} == line_num
         line_num += 1
       end