Apply suggestions from code review

Signed-off-by: Shingo Nakayama <nkymsng@akane.waseda.jp>

Co-authored-by: Daijiro Fukuda <fukuda@clear-code.com>

lib/fluent/plugin/out_file.rb

@@ -172,15 +172,14 @@ def configure(conf)
           log.warn "symlink_path is unavailable on Windows platform. disabled."
           @symlink_path = nil
         else
-          #add check if symlink_path has a tag placeholder.
-            placeholder_validators(:symlink_path, @symlink_path).reject{|v| v.type == :time }.each do |v|
+          placeholder_validators(:symlink_path, @symlink_path).reject{ |v| v.type == :time }.each do |v|
             begin
               v.validate!
+            rescue Fluent::ConfigError => e
+              log.warn "#{e}. This means multiple chunks are competing for a single symlink_path, so some logs may not be taken from the symlink."
             end
-          rescue Fluent::ConfigError => e
-            log.warn "#{e}. This means multiple chunks are competing for a single symlink_path, so some logs may not be taken from the symlink."
           end
-          
+
           @buffer.extend SymlinkBufferMixin
           @buffer.symlink_path = @symlink_path
           @buffer.output_plugin_for_symlink = self

test/plugin/test_out_file.rb

@@ -184,7 +184,8 @@ def create_driver(conf = CONFIG, opts = {})
       end
     end
 
-    test 'symlink path has not tag placeholder or key placeholder' do
+    test 'warning for symlink_path not including correct placeholders corresponding to chunk keys' do
+      omit "Windows doesn't support symlink" if Fluent.windows?
       conf = config_element('match', '**', {
           'path' => "#{TMP_DIR}/${tag}/${key1}/${key2}/conf_test.%Y%m%d.%H%M.log",
           'symlink_path' => "#{TMP_DIR}/conf_test.current.log",
@@ -198,7 +199,7 @@ def create_driver(conf = CONFIG, opts = {})
       assert_nothing_raised do
         d = create_driver(conf)
         assert do
-          d.logs.count { |log| log.include?("symlink_path:") } == 2
+          d.logs.count { |log| log.include?("multiple chunks are competing for a single symlink_path") } == 2
         end
       end
     end