Refactor: unify event updates to happen in one place (#297)

+ Test: a try that actually re-tries on `RSpec::Expectations::ExpectationNotMetError`

+ Test: re-try instead of relying on timeout

Author: kares

lib/logstash/inputs/file.rb

@@ -373,12 +373,11 @@ def run(queue)
     @completely_stopped.make_true
   end # def run
 
-  def post_process_this(event)
+  def post_process_this(event, path)
+    event.set("[@metadata][path]", path)
     event.set("[@metadata][host]", @host)
     attempt_set(event, @source_host_field, @host)
-
-    source_path = event.get('[@metadata][path]') and
-      attempt_set(event, @source_path_field, source_path)
+    attempt_set(event, @source_path_field, path) if path
 
     decorate(event)
     @queue.get << event

lib/logstash/inputs/file_listener.rb

@@ -40,8 +40,7 @@ def accept(data)
     end
 
     def process_event(event)
-      event.set("[@metadata][path]", path)
-      input.post_process_this(event)
+      input.post_process_this(event, path)
     end
 
   end

spec/inputs/file_read_spec.rb

@@ -338,7 +338,7 @@
       sincedb_content = File.read(sincedb_path).strip
       expect( sincedb_content ).to_not be_empty
 
-      Stud.try(3.times) do
+      try(3) do
         sleep(1.5) # > sincedb_clean_after
 
         sincedb_content = File.read(sincedb_path).strip
@@ -363,7 +363,10 @@ def wait_for_start_processing(run_thread, timeout: 1.0)
     end
   end
 
-  def wait_for_file_removal(path, timeout: 3 * interval)
-    wait(timeout).for { File.exist?(path) }.to be_falsey
+  def wait_for_file_removal(path)
+    timeout = interval
+    try(5) do
+      wait(timeout).for { File.exist?(path) }.to be_falsey
+    end
   end
 end