Check for timezone aware rails code (using Cane: https://github.com/square/cane)

code_check.rb

require 'set'
require 'cane/file'
require 'cane/task_runner'

module CaneExt

  # Creates violations for files that do not meet code requirements.
  class CodeCheck < Struct.new(:opts)
    include Cane::CLI

    def initialize(*args)
      options = args.first.merge!(defaults(self.class))

      super(options)
    end

    def self.key; :code; end
    def self.name; "code checking"; end
    def self.options
      {
        code_glob: [ 'Glob to run code checks over',
                       default:  '{app,lib,spec}/**/*.rb',
                       variable: 'GLOB',
                       clobber: :no_code
                    ],
        code_exclude: [ 'Exclude from code check',
                      variable: 'GLOB',
                      default: ['lib/cane_ext/*'],
                      clobber: :no_code
                  ],
        code_timezones: [ 'Time zone aware commands',
                      default: {
                        'Date.today' => 'Time.zone.today',
                        'Time.now' => 'Time.zone.now',
                        'DateTime.now' => 'Time.zone.now',
                        'Time.at' => 'Time.zone.at',
                        'Time.parse' => 'Time.zone.parse',
                        'Time.new' => 'Time.zone.local',
                        'DateTime.new' => 'Time.zone.local',
                        'DateTime.strptime' => 'Time.zone.strptime'
                      },
                      variable: 'FILE',
                      clobber: :no_zone
                  ],
        no_code:   ['Disable code checking', cast: ->(x) { !x }]
      }
    end

    def violations
      return [] if opts[:no_code]

      worker.map(file_list) do |file_path|
        map_lines(file_path) do |line, line_number|
          violations_for_line(line.chomp).map {|message| {
            file:        file_path,
            line:        line_number + 1,
            label:       message,
            description: "Lines violated code requirements"
          }}
        end
      end.flatten
    end

    protected

    def violations_for_line(line)
      result = []
      matched_zone_violation = /#{escaped_timezone_aware_violations.join('|')}/i.match(line)

      result << "Line contains code that is not timezone aware: '#{matched_zone_violation}' should be '#{timezone_aware_violations[matched_zone_violation.to_s]}'" if matched_zone_violation
      result
    end

    def timezone_aware_violations
      opts.fetch(:code_timezones)
    end

    def escaped_timezone_aware_violations
      timezone_aware_violations.keys.map { |violation| Regexp.escape(violation) }
    end

    def file_list
      Dir[opts.fetch(:code_glob)].reject {|f| excluded?(f) }
    end

    def exclusions
      @exclusions ||= opts.fetch(:code_exclude, []).flatten.map do |i|
        Dir[i]
      end.flatten.to_set
    end

    def excluded?(file)
      exclusions.include?(file)
    end


    def map_lines(file_path, &block)
      Cane::File.iterator(file_path).map.with_index(&block)
    end

    def worker
      Cane.task_runner(opts)
    end
  end

end