Bump rubocop version to 1.48.1. (#101)

Also bump gem version to 0.0.15.

.github/workflows/ci.yml

@@ -6,9 +6,8 @@ jobs:
       fail-fast: false
       matrix:
         rvm:
+          - 2.7
           - 2.6
-          - 2.5
-          - 2.4
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2

.rubocop.yml

@@ -5,6 +5,14 @@
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
+AllCops:
+  TargetRubyVersion: 2.6
+  NewCops: disable
+
+# Rakefile doesn't need to be executable.
+Lint/ScriptPermission:
+  Enabled: false
+
 # Offense count: 2
 Metrics/AbcSize:
   Max: 120
@@ -31,3 +39,12 @@ Metrics/MethodLength:
 # Offense count: 3
 Metrics/PerceivedComplexity:
   Max: 50
+
+# Offense count: 1
+# Configuration parameters: CountComments.
+Metrics/BlockLength:
+  Max: 50
+
+# TODO: Re-enable this and fix frozen strings.
+Style/FrozenStringLiteralComment:
+  Enabled: false

Rakefile

@@ -36,13 +36,14 @@ task :fix_perms do
   files.each do |file|
     mode = File.stat(file).mode & 0o777
     next unless mode & 0o444 != 0o444
+
     puts "Changing mode of #{file} from #{mode.to_s(8)} to "\
          "#{(mode | 0o444).to_s(8)}"
     chmod mode | 0o444, file
   end
 end
 
 desc 'Run unit tests and RuboCop to check for style violations'
-task all: [:test, :rubocop, :fix_perms]
+task all: %i[rubocop test fix_perms]
 
 task default: :all

fluent-plugin-detect-exceptions.gemspec

@@ -1,29 +1,29 @@
 Gem::Specification.new do |gem|
   gem.name          = 'fluent-plugin-detect-exceptions'
-  gem.description   = <<-eos
+  gem.description   = <<-DESCRIPTION
    Fluentd output plugin which detects exception stack traces in a stream of
    JSON log messages and combines all single-line messages that belong to the
    same stack trace into one multi-line message.
    This is an official Google Ruby gem.
-eos
+  DESCRIPTION
   gem.summary       = \
     'fluentd output plugin for combining stack traces as multi-line JSON logs'
   gem.homepage      = \
     'https://github.com/GoogleCloudPlatform/fluent-plugin-detect-exceptions'
   gem.license       = 'Apache-2.0'
-  gem.version       = '0.0.14'
+  gem.version       = '0.0.15'
   gem.authors       = ['Stackdriver Agents']
   gem.email         = ['[email protected]']
-  gem.required_ruby_version = Gem::Requirement.new('>= 2.0')
+  gem.required_ruby_version = Gem::Requirement.new('>= 2.6')
 
   gem.files         = Dir['**/*'].keep_if { |file| File.file?(file) }
   gem.test_files    = gem.files.grep(/^(test)/)
   gem.require_paths = ['lib']
 
   gem.add_runtime_dependency 'fluentd', '>= 0.10'
 
+  gem.add_development_dependency 'flexmock', '~> 2.0'
   gem.add_development_dependency 'rake', '~> 10.3'
-  gem.add_development_dependency 'rubocop', '= 0.42.0'
+  gem.add_development_dependency 'rubocop', '= 1.48.1'
   gem.add_development_dependency 'test-unit', '~> 3.0'
-  gem.add_development_dependency 'flexmock', '~> 2.0'
 end

lib/fluent/plugin/exception_detector.rb

@@ -21,9 +21,9 @@ module ExceptionDetectorConfig
     class RuleTarget
       attr_accessor :pattern, :to_state
 
-      def initialize(p, s)
-        @pattern = p
-        @to_state = s
+      def initialize(pattern, state)
+        @pattern = pattern
+        @to_state = state
       end
 
       def ==(other)
@@ -52,28 +52,28 @@ def self.supported
     end
 
     JAVA_RULES = [
-      rule([:start_state, :java_start_exception],
+      rule(%i[start_state java_start_exception],
            /(?:Exception|Error|Throwable|V8 errors stack trace)[:\r\n]/,
            :java_after_exception),
       rule(:java_after_exception, /^[\t ]*nested exception is:[\t ]*/,
            :java_start_exception),
       rule(:java_after_exception, /^[\r\n]*$/, :java_after_exception),
-      rule([:java_after_exception, :java], /^[\t ]+(?:eval )?at /, :java),
+      rule(%i[java_after_exception java], /^[\t ]+(?:eval )?at /, :java),
 
-      rule([:java_after_exception, :java],
+      rule(%i[java_after_exception java],
            # C# nested exception.
            /^[\t ]+--- End of inner exception stack trace ---$/,
            :java),
 
-      rule([:java_after_exception, :java],
+      rule(%i[java_after_exception java],
            # C# exception from async code.
            /^--- End of stack trace from previous (?x:
            )location where exception was thrown ---$/,
            :java),
 
-      rule([:java_after_exception, :java], /^[\t ]*(?:Caused by|Suppressed):/,
+      rule(%i[java_after_exception java], /^[\t ]*(?:Caused by|Suppressed):/,
            :java_after_exception),
-      rule([:java_after_exception, :java],
+      rule(%i[java_after_exception java],
            /^[\t ]*... \d+ (?:more|common frames omitted)/, :java)
     ].freeze
 
@@ -97,13 +97,13 @@ def self.supported
       rule(:start_state, /\bpanic: /, :go_after_panic),
       rule(:start_state, /http: panic serving/, :go_goroutine),
       rule(:go_after_panic, /^$/, :go_goroutine),
-      rule([:go_after_panic, :go_after_signal, :go_frame_1],
+      rule(%i[go_after_panic go_after_signal go_frame_line1],
            /^$/, :go_goroutine),
       rule(:go_after_panic, /^\[signal /, :go_after_signal),
-      rule(:go_goroutine, /^goroutine \d+ \[[^\]]+\]:$/, :go_frame_1),
-      rule(:go_frame_1, /^(?:[^\s.:]+\.)*[^\s.():]+\(|^created by /,
-           :go_frame_2),
-      rule(:go_frame_2, /^\s/, :go_frame_1)
+      rule(:go_goroutine, /^goroutine \d+ \[[^\]]+\]:$/, :go_frame_line1),
+      rule(:go_frame_line1, /^(?:[^\s.:]+\.)*[^\s.():]+\(|^created by /,
+           :go_frame_line2),
+      rule(:go_frame_line2, /^\s/, :go_frame_line1)
     ].freeze
 
     RUBY_RULES = [
@@ -129,22 +129,22 @@ def self.supported
       rule(:dart_exc, /^Concurrent modification/, :dart_stack),
       rule(:dart_exc, /^Out of Memory/, :dart_stack),
       rule(:dart_exc, /^Stack Overflow/, :dart_stack),
-      rule(:dart_exc, /^'.+?':.+?$/, :dart_type_err_1),
-      rule(:dart_type_err_1, /^#\d+\s+.+?\(.+?\)$/, :dart_stack),
-      rule(:dart_type_err_1, /^.+?$/, :dart_type_err_2),
-      rule(:dart_type_err_2, /^.*?\^.*?$/, :dart_type_err_3),
-      rule(:dart_type_err_3, /^$/, :dart_type_err_4),
-      rule(:dart_type_err_4, /^$/, :dart_stack),
-      rule(:dart_exc, /^FormatException/, :dart_format_err_1),
-      rule(:dart_format_err_1, /^#\d+\s+.+?\(.+?\)$/, :dart_stack),
-      rule(:dart_format_err_1, /^./, :dart_format_err_2),
-      rule(:dart_format_err_2, /^.*?\^/, :dart_format_err_3),
-      rule(:dart_format_err_3, /^$/, :dart_stack),
-      rule(:dart_exc, /^NoSuchMethodError:/, :dart_method_err_1),
-      rule(:dart_method_err_1, /^Receiver:/, :dart_method_err_2),
-      rule(:dart_method_err_2, /^Tried calling:/, :dart_method_err_3),
-      rule(:dart_method_err_3, /^Found:/, :dart_stack),
-      rule(:dart_method_err_3, /^#\d+\s+.+?\(.+?\)$/, :dart_stack),
+      rule(:dart_exc, /^'.+?':.+?$/, :dart_type_err_line1),
+      rule(:dart_type_err_line1, /^#\d+\s+.+?\(.+?\)$/, :dart_stack),
+      rule(:dart_type_err_line1, /^.+?$/, :dart_type_err_line2),
+      rule(:dart_type_err_line2, /^.*?\^.*?$/, :dart_type_err_line3),
+      rule(:dart_type_err_line3, /^$/, :dart_type_err_line4),
+      rule(:dart_type_err_line4, /^$/, :dart_stack),
+      rule(:dart_exc, /^FormatException/, :dart_format_err_line1),
+      rule(:dart_format_err_line1, /^#\d+\s+.+?\(.+?\)$/, :dart_stack),
+      rule(:dart_format_err_line1, /^./, :dart_format_err_line2),
+      rule(:dart_format_err_line2, /^.*?\^/, :dart_format_err_line3),
+      rule(:dart_format_err_line3, /^$/, :dart_stack),
+      rule(:dart_exc, /^NoSuchMethodError:/, :dart_method_err_line1),
+      rule(:dart_method_err_line1, /^Receiver:/, :dart_method_err_line2),
+      rule(:dart_method_err_line2, /^Tried calling:/, :dart_method_err_line3),
+      rule(:dart_method_err_line3, /^Found:/, :dart_stack),
+      rule(:dart_method_err_line3, /^#\d+\s+.+?\(.+?\)$/, :dart_stack),
       rule(:dart_stack, /^#\d+\s+.+?\(.+?\)$/, :dart_stack),
       rule(:dart_stack, /^<asynchronous suspension>$/, :dart_stack)
     ].freeze
@@ -168,7 +168,7 @@ def self.supported
       all: ALL_RULES
     }.freeze
 
-    DEFAULT_FIELDS = %w(message log).freeze
+    DEFAULT_FIELDS = %w[message log].freeze
   end
 
   # State machine that consumes individual log lines and detects
@@ -236,6 +236,7 @@ def reset
     def transition(line)
       @rules[@state].each do |r|
         next unless line =~ r.pattern
+
         @state = r.to_state
         return true
       end
@@ -280,14 +281,14 @@ def push(time_sec, record)
         @exception_detector.reset
         detection_status = :no_trace
       else
-        force_flush if @max_bytes > 0 &&
+        force_flush if @max_bytes.positive? &&
                        @buffer_size + message.length > @max_bytes
         detection_status = @exception_detector.update(message)
       end
 
       update_buffer(detection_status, time_sec, record, message)
 
-      force_flush if @max_lines > 0 && @messages.length == @max_lines
+      force_flush if @max_lines.positive? && @messages.length == @max_lines
     end
 
     def flush
@@ -332,8 +333,7 @@ def extract_message(record)
     end
 
     def update_buffer(detection_status, time_sec, record, message)
-      trigger_emit = detection_status == :no_trace ||
-                     detection_status == :end_trace
+      trigger_emit = %i[no_trace end_trace].include?(detection_status)
       if @messages.empty? && trigger_emit
         @emit.call(time_sec, record)
         return
@@ -361,16 +361,16 @@ def add(time_sec, record, message)
         @first_timestamp = time_sec
         @buffer_start_time = Time.now
       end
-      unless message.nil?
-        message_with_line_break =
-          if @force_line_breaks && !@messages.empty? && !message.include?("\n")
-            "\n" + message
-          else
-            message
-          end
-        @messages << message_with_line_break
-        @buffer_size += message_with_line_break.length
-      end
+      return if message.nil?
+
+      message_with_line_break =
+        if @force_line_breaks && !@messages.empty? && !message.include?("\n")
+          "\n#{message}"
+        else
+          message
+        end
+      @messages << message_with_line_break
+      @buffer_size += message_with_line_break.length
     end
   end
 end

lib/fluent/plugin/out_detect_exceptions.rb

@@ -44,9 +44,7 @@ class DetectExceptionsOutput < Output
     def configure(conf)
       super
 
-      if multiline_flush_interval
-        @check_flush_interval = [multiline_flush_interval * 0.1, 1].max
-      end
+      @check_flush_interval = [multiline_flush_interval * 0.1, 1].max if multiline_flush_interval
 
       @languages = languages.map(&:to_sym)
 
@@ -57,11 +55,11 @@ def configure(conf)
     def start
       super
 
-      if multiline_flush_interval
-        @flush_buffer_mutex = Mutex.new
-        @stop_check = false
-        @thread = Thread.new(&method(:check_flush_loop))
-      end
+      return unless multiline_flush_interval
+
+      @flush_buffer_mutex = Mutex.new
+      @stop_check = false
+      @thread = Thread.new(&method(:check_flush_loop))
     end
 
     def before_shutdown
@@ -77,8 +75,8 @@ def shutdown
       super
     end
 
-    def emit(tag, es, chain)
-      es.each do |time_sec, record|
+    def emit(tag, entries, chain)
+      entries.each do |time_sec, record|
         process_record(tag, time_sec, record)
       end
       chain.next
@@ -121,13 +119,14 @@ def check_flush_loop
           @flush_buffer_mutex.sleep(@check_flush_interval)
           now = Time.now
           break if @stop_check
+
           @accumulators.each_value do |acc|
             acc.force_flush if now - acc.buffer_start_time >
                                @multiline_flush_interval
           end
         end
       end
-    rescue
+    rescue StandardError
       log.error 'error in check_flush_loop', error: $ERROR_INFO.to_s
       log.error_backtrace
     end

test/helper.rb

@@ -14,29 +14,29 @@
 
 require 'rubygems'
 require 'bundler'
-
 begin
   Bundler.setup(:default, :development)
 rescue Bundler::BundlerError => e
+  # rubocop:disable Style/StderrPuts
   $stderr.puts e.message
   $stderr.puts 'Run `bundle install` to install missing gems'
+  # rubocop:enable Style/StderrPuts
   exit e.status_code
 end
-
 require 'test/unit'
 
 $LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
 $LOAD_PATH.unshift(File.dirname(__FILE__))
 require 'fluent/test'
-
 unless ENV.key?('VERBOSE')
   nulllogger = Object.new
   nulllogger.instance_eval do |_|
-    def respond_to_missing?
+    def respond_to_missing?(_method, _include_private = false)
       true
     end
 
-    def method_missing(_method, *_args) # rubocop:disable Style/MethodMissing
+    def method_missing(_method, *_args)
+      # pass
     end
   end
   # global $log variable is used by fluentd