Suppress a lot of warnings

* Do not shadow local variables

test/plugin/test_in_dummy.rb:91: warning: assigned but unused variable - time
lib/fluent/plugin/in_dummy.rb:45: warning: shadowing outer local variable - e
test/test_event.rb:94: warning: shadowing outer local variable - time
test/test_event.rb:142: warning: shadowing outer local variable - time
test/plugin/test_in_stream.rb:20: warning: shadowing outer local variable - time
test/plugin/test_in_stream.rb:35: warning: shadowing outer local variable - time
test/plugin/test_in_stream.rb:51: warning: shadowing outer local variable - time
test/plugin/test_in_stream.rb:68: warning: shadowing outer local variable - time
test/plugin/test_in_stream.rb:84: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:43: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:59: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:75: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:113: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:150: warning: shadowing outer local variable - tag
test/plugin/test_in_http.rb:163: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:184: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:200: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:238: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:262: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:280: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:43: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:59: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:75: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:113: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:150: warning: shadowing outer local variable - tag
test/plugin/test_in_http.rb:163: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:184: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:200: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:238: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:262: warning: shadowing outer local variable - time
test/plugin/test_in_http.rb:280: warning: shadowing outer local variable - time

* Initialize uninitialized instance variables

lib/fluent/test/base.rb:31: warning: instance variable @now not initialized
lib/fluent/test/input_test.rb:121: warning: instance variable @run_post_conditions not initialized
lib/fluent/log.rb:324: warning: instance variable @suppress_repeated_stacktrace not initialized
lib/fluent/config/configure_proxy.rb:183: warning: instance variable @current_description not initialized
lib/fluent/plugin/buf_file.rb:147: warning: instance variable @symlink_path not initialized
lib/fluent/output.rb:212: warning: instance variable @secondary not initialized
lib/fluent/output.rb:220: warning: instance variable @secondary not initialized
lib/fluent/mixin.rb:201: warning: instance variable @localtime not initialized
lib/fluent/mixin.rb:201: warning: instance variable @Timezone not initialized
lib/fluent/mixin.rb:149: warning: instance variable @remove_tag_prefix not initialized
lib/fluent/mixin.rb:150: warning: instance variable @remove_tag_suffix not initialized
test/config/test_system_config.rb:81: warning: instance variable @emit_error_log_interval not initialized
lib/fluent/plugin/in_syslog.rb:111: warning: instance variable @use_default not initialized
lib/fluent/root_agent.rb:89: warning: instance variable @without_source not initialized
lib/fluent/process.rb:488: warning: instance variable @detach_process not initialized

* Define assert_equal_event_time once

lib/fluent/test/base.rb:35: warning: method redefined; discarding old assert_equal_event_time
lib/fluent/test/base.rb:35: warning: previous definition of assert_equal_event_time was here

* Add '_' prefix to unused variables

test/test_parser.rb:1046: warning: assigned but unused variable - time
lib/fluent/test/output_test.rb:91: warning: assigned but unused variable - record
lib/fluent/config/element.rb:138: warning: assigned but unused variable - block

* Remove unused variables

test/test_parser.rb:453: warning: assigned but unused variable - format
test/test_mixin.rb:211: warning: assigned but unused variable - d
test/test_formatter.rb:55: warning: assigned but unused variable - formatter
test/test_buffer.rb:581: warning: assigned but unused variable - e
test/config/test_dsl.rb:164: warning: assigned but unused variable - root
lib/fluent/parser.rb:619: warning: assigned but unused variable - e
lib/fluent/plugin/in_exec.rb:56: warning: assigned but unused variable - localtime
lib/fluent/plugin/in_exec.rb:58: warning: assigned but unused variable - utc
lib/fluent/event_router.rb:105: warning: assigned but unused variable - c

* Rename block parameter

lib/fluent/config/v1_parser.rb:159: warning: shadowing outer local variable - path
lib/fluent/config/parser.rb:84: warning: shadowing outer local variable - path
lib/fluent/plugin/buf_file.rb:175: warning: assigned but unused variable - chunk
lib/fluent/plugin/buf_file.rb:177: warning: assigned but unused variable - timestamp
lib/fluent/plugin/buf_file.rb:181: warning: assigned but unused variable - chunk
lib/fluent/plugin/buf_file.rb:183: warning: assigned but unused variable - timestamp

* Use defined global variable

lib/fluent/plugin.rb:129: warning: global variable `$log' not initialized

* Remove redundant condition

lib/fluent/log.rb:255: warning: instance variable @suppress_repeated_stacktrace not initialized
lib/fluent/log.rb:261: warning: instance variable @suppress_repeated_stacktrace not initialized

* Define instance method once

lib/fluent/plugin/in_tail.rb:457: warning: method redefined; discarding old swap_state
lib/fluent/plugin/in_tail.rb:457: warning: previous definition of swap_state was here

lib/fluent/config/configure_proxy.rb

@@ -52,6 +52,7 @@ def initialize(name, opts = {})
         @defaults = {}
         @descriptions = {}
         @sections = {}
+        @current_description = nil
       end
 
       def required?

lib/fluent/config/element.rb

@@ -135,7 +135,7 @@ def secret_param?(key)
 
         param_key = key.to_sym
         @corresponding_proxies.each { |proxy|
-          block, opts = proxy.params[param_key]
+          _block, opts = proxy.params[param_key]
           if opts && opts.has_key?(:secret)
             return opts[:secret]
           end

lib/fluent/config/parser.rb

@@ -81,10 +81,10 @@ def process_include(attrs, elems, uri, allow_include = true)
             pattern = path
           end
 
-          Dir.glob(pattern).sort.each { |path|
-            basepath = File.dirname(path)
-            fname = File.basename(path)
-            File.open(path) { |f|
+          Dir.glob(pattern).sort.each { |entry|
+            basepath = File.dirname(entry)
+            fname = File.basename(entry)
+            File.open(entry) { |f|
               Parser.new(basepath, f.each_line, fname).parse!(allow_include, nil, attrs, elems)
             }
           }

lib/fluent/config/v1_parser.rb

@@ -156,10 +156,10 @@ def eval_include(attrs, elems, uri)
             pattern = path
           end
 
-          Dir.glob(pattern).sort.each { |path|
-            basepath = File.dirname(path)
-            fname = File.basename(path)
-            data = File.read(path)
+          Dir.glob(pattern).sort.each { |entry|
+            basepath = File.dirname(entry)
+            fname = File.basename(entry)
+            data = File.read(entry)
             data.force_encoding('UTF-8')
             ss = StringScanner.new(data)
             V1Parser.new(ss, basepath, fname, @eval_context).parse_element(true, nil, attrs, elems)

lib/fluent/event_router.rb

@@ -102,7 +102,7 @@ def match?(tag)
 
     def match(tag)
       collector = @match_cache.get(tag) {
-        c = find(tag) || @default_collector
+        find(tag) || @default_collector
       }
       collector
     end

lib/fluent/log.rb

@@ -68,9 +68,7 @@ def initialize(out=STDERR, level=LEVEL_TRACE, opts={})
       # Fluent::Engine requires Fluent::Log, so we must take that object lazily
       @engine = Fluent.const_get('Engine')
 
-      if opts.has_key?(:suppress_repeated_stacktrace)
-        @suppress_repeated_stacktrace = opts[:suppress_repeated_stacktrace]
-      end
+      @suppress_repeated_stacktrace = opts[:suppress_repeated_stacktrace]
     end
 
     attr_accessor :out
@@ -320,7 +318,9 @@ def initialize(logger)
       @logger = logger
       @level = @logger.level
       @depth_offset = 2
-      @suppress_repeated_stacktrace = logger.instance_variable_get(:@suppress_repeated_stacktrace)
+      if logger.instance_variable_defined?(:@suppress_repeated_stacktrace)
+        @suppress_repeated_stacktrace = logger.instance_variable_get(:@suppress_repeated_stacktrace)
+      end
 
       enable_color @logger.enable_color?
     end

lib/fluent/mixin.rb

@@ -133,13 +133,18 @@ module HandleTagNameMixin
     attr_accessor :remove_tag_prefix, :remove_tag_suffix, :add_tag_prefix, :add_tag_suffix
     def configure(conf)
       super
-      if remove_tag_prefix = conf['remove_tag_prefix']
-        @remove_tag_prefix = Regexp.new('^' + Regexp.escape(remove_tag_prefix))
-      end
 
-      if remove_tag_suffix = conf['remove_tag_suffix']
-        @remove_tag_suffix = Regexp.new(Regexp.escape(remove_tag_suffix) + '$')
-      end
+      @remove_tag_prefix = if conf.has_key?('remove_tag_prefix')
+                             Regexp.new('^' + Regexp.escape(conf['remove_tag_prefix']))
+                           else
+                             nil
+                           end
+
+      @remove_tag_suffix = if conf.has_key?('remove_tag_suffix')
+                             Regexp.new(Regexp.escape(conf['remove_tag_suffix']) + '$')
+                           else
+                             nil
+                           end
 
       @add_tag_prefix = conf['add_tag_prefix']
       @add_tag_suffix = conf['add_tag_suffix']
@@ -162,6 +167,8 @@ module SetTimeKeyMixin
 
     def configure(conf)
       @include_time_key = false
+      @localtime = false
+      @timezone = nil
 
       super
 
@@ -257,6 +264,7 @@ def self.included(klass)
     def configure(conf)
       super
 
+      @type_converters = nil
       @type_converters = parse_types_parameter unless @types.nil?
     end
 

lib/fluent/output.rb

@@ -146,6 +146,7 @@ def initialize
       @next_retry_time = 0
       @num_errors = 0
       @num_errors_lock = Mutex.new
+      @secondary = nil
       @secondary_limit = 8
       @emit_count = 0
     end

lib/fluent/parser.rb

@@ -616,7 +616,7 @@ def self.lookup(format)
         # built-in template
         begin
           Fluent::Plugin.new_parser(format)
-        rescue ConfigError => e # keep same error message
+        rescue ConfigError # keep same error message
           raise ConfigError, "Unknown format template '#{format}'"
         end
       end

lib/fluent/plugin.rb

@@ -126,7 +126,7 @@ def self.register_impl(kind, registry, type, value)
         raise Fluent::ConfigError, "Invalid implementation as #{kind} plugin: '#{type}'. It must be a Class, or callable."
       end
       registry.register(type, value)
-      $log.trace "registered #{kind} plugin '#{type}'" if $log
+      $log.trace "registered #{kind} plugin '#{type}'" if defined?($log)
       nil
     end
 

lib/fluent/plugin/buf_file.rb

@@ -100,6 +100,7 @@ def initialize
       super
 
       @uri_parser = URI::Parser.new
+      @symlink_path = nil
     end
 
     desc 'The path where buffer chunks are stored.'
@@ -171,15 +172,15 @@ def resume
       }
 
       map = {}
-      maps.sort_by {|(timestamp,chunk)|
+      maps.sort_by {|(timestamp,_chunk)|
         timestamp
-      }.each {|(timestamp,chunk)|
+      }.each {|(_timestamp,chunk)|
         map[chunk.key] = chunk
       }
 
-      queue = queues.sort_by {|(timestamp,chunk)|
+      queue = queues.sort_by {|(timestamp,_chunk)|
         timestamp
-      }.map {|(timestamp,chunk)|
+      }.map {|(_timestamp,chunk)|
         chunk
       }
 

lib/fluent/plugin/in_dummy.rb

@@ -35,11 +35,11 @@ class DummyInput < Input
     config_param :dummy, default: [{"message"=>"dummy"}] do |val|
       begin
         parsed = JSON.parse(val)
-      rescue JSON::ParserError => e
+      rescue JSON::ParserError => ex
         # Fluent::ConfigParseError, "got incomplete JSON" will be raised
         # at literal_parser.rb with --use-v1-config, but I had to
         # take care at here for the case of --use-v0-config.
-        raise Fluent::ConfigError, "#{e.class}: #{e.message}"
+        raise Fluent::ConfigError, "#{ex.class}: #{ex.message}"
       end
       dummy = parsed.is_a?(Array) ? parsed : [parsed]
       dummy.each_with_index do |e, i|

lib/fluent/plugin/in_exec.rb

@@ -53,9 +53,9 @@ def initialize
     def configure(conf)
       super
 
-      if localtime = conf['localtime']
+      if conf['localtime']
         @localtime = true
-      elsif utc = conf['utc']
+      elsif conf['utc']
         @localtime = false
       end
 

lib/fluent/plugin/in_syslog.rb

@@ -96,6 +96,8 @@ def initialize
     def configure(conf)
       super
 
+      @use_default = false
+
       if conf.has_key?('format')
         @parser = Plugin.new_parser(conf['format'])
         @parser.configure(conf)

lib/fluent/plugin/in_tail.rb

@@ -453,16 +453,16 @@ def on_rotate(io)
             @update_watcher.call(@path, swap_state(@pe))
           end
         end
+      end
 
-        def swap_state(pe)
-          # Use MemoryPositionEntry for rotated file temporary
-          mpe = MemoryPositionEntry.new
-          mpe.update(pe.read_inode, pe.read_pos)
-          @pe = mpe
-          @io_handler.pe = mpe # Don't re-create IOHandler because IOHandler has an internal buffer.
+      def swap_state(pe)
+        # Use MemoryPositionEntry for rotated file temporary
+        mpe = MemoryPositionEntry.new
+        mpe.update(pe.read_inode, pe.read_pos)
+        @pe = mpe
+        @io_handler.pe = mpe # Don't re-create IOHandler because IOHandler has an internal buffer.
 
-          pe # This pe will be updated in on_rotate after TailWatcher is initialized
-        end
+        pe # This pe will be updated in on_rotate after TailWatcher is initialized
       end
 
       class TimerWatcher < Coolio::TimerWatcher

lib/fluent/process.rb

@@ -418,6 +418,8 @@ module DetachProcessMixin
     def configure(conf)
       super
 
+      @detach_process = nil
+
       if detach_process = conf['detach_process']
         b3v = Config.bool_value(detach_process)
         case b3v
@@ -461,6 +463,8 @@ def initialize
     def configure(conf)
       super
 
+      @detach_process = nil
+
       if detach_process = conf['detach_process']
         b3v = Config.bool_value(detach_process)
         case b3v

lib/fluent/root_agent.rb

@@ -55,6 +55,7 @@ def initialize(system_config = SystemConfig.new)
       @started_inputs = []
       @suppress_emit_error_log_interval = 0
       @next_emit_error_log_time = nil
+      @without_source = false
 
       suppress_interval(system_config.emit_error_log_interval) unless system_config.emit_error_log_interval.nil?
       @without_source = system_config.without_source unless system_config.without_source.nil?

lib/fluent/test/base.rb

@@ -28,14 +28,7 @@ def self.setup
         @now = n
       }
       engine.define_singleton_method(:now) {
-        @now || super()
-      }
-
-      ::Test::Unit::Assertions.module_eval {
-        def assert_equal_event_time(a, b)
-          assert_equal(a.sec, b.sec)
-          assert_equal(a.nsec, b.nsec)
-        end
+        @now ||= super()
       }
 
       nil
@@ -131,3 +124,10 @@ def logs
     end
   end
 end
+
+Test::Unit::Assertions.module_eval do
+  def assert_equal_event_time(a, b)
+    assert_equal(a.sec, b.sec)
+    assert_equal(a.nsec, b.nsec)
+  end
+end

lib/fluent/test/input_test.rb

@@ -36,6 +36,7 @@ def initialize(klass, &block)
         # for checking only the number of emitted records during run
         @expected_emits_length = nil
         @run_timeout = 5
+        @run_post_conditions = []
       end
 
       def expect_emit(tag, time, record)
@@ -81,7 +82,6 @@ def records
 
       def register_run_post_condition(&block)
         if block
-          @run_post_conditions ||= []
           @run_post_conditions << block
         end
       end

lib/fluent/test/output_test.rb

@@ -88,7 +88,7 @@ def run(num_waits = 10, &block)
           key = ''
           if @instance.respond_to?(:time_slicer)
             # this block is only for test_out_file
-            time, record = @entries.first
+            time, _record = @entries.first
             key = @instance.time_slicer.call(time)
           end
           chunk = @instance.buffer.new_chunk(key)

test/config/test_dsl.rb

@@ -161,7 +161,7 @@ def setup
     sub_test_case 'with configuration that returns non element on top' do
       sub_test_case '.parse' do
         test 'does not crash' do
-          root = Fluent::Config::DSL::Parser.parse(DSL_CONFIG_RETURNS_NON_ELEMENT, 'dsl_config_returns_non_element.rb')
+          Fluent::Config::DSL::Parser.parse(DSL_CONFIG_RETURNS_NON_ELEMENT, 'dsl_config_returns_non_element.rb')
         end
       end
     end

test/config/test_system_config.rb

@@ -20,6 +20,7 @@ def initialize
       @suppress_config_dump = nil
       @suppress_repeated_stacktrace = nil
       @without_source = nil
+      @emit_error_log_interval = nil
     end
   end