rubocop-hq/rubocop

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lib/rubocop/cop/metrics/class_length.rb

Summary

Maintainability
A
25 mins
Test Coverage
A
100%
# frozen_string_literal: true

module RuboCop
  module Cop
    module Metrics
      # Checks if the length of a class exceeds some maximum value.
      # Comment lines can optionally be ignored.
      # The maximum allowed length is configurable.
      #
      # You can set constructs you want to fold with `CountAsOne`.
      # Available are: 'array', 'hash', 'heredoc', and 'method_call'. Each construct
      # will be counted as one line regardless of its actual size.
      #
      # NOTE: This cop also applies for `Struct` definitions.
      #
      # @example CountAsOne: ['array', 'heredoc', 'method_call']
      #
      #   class Foo
      #     ARRAY = [         # +1
      #       1,
      #       2
      #     ]
      #
      #     HASH = {          # +3
      #       key: 'value'
      #     }
      #
      #     MSG = <<~HEREDOC  # +1
      #       Heredoc
      #       content.
      #     HEREDOC
      #
      #     foo(              # +1
      #       1,
      #       2
      #     )
      #   end                 # 6 points
      #
      class ClassLength < Base
        include CodeLength

        def on_class(node)
          check_code_length(node)
        end

        def on_sclass(node)
          return if node.each_ancestor(:class).any?

          on_class(node)
        end

        def on_casgn(node)
          parent = node.parent

          if parent&.assignment?
            block_node = parent.children[1]
          elsif parent&.parent&.masgn_type?
            block_node = parent.parent.children[1]
          else
            _scope, _name, block_node = *node
          end

          return unless block_node.respond_to?(:class_definition?) && block_node.class_definition?

          check_code_length(block_node)
        end

        private

        def message(length, max_length)
          format('Class has too many lines. [%<length>d/%<max>d]', length: length, max: max_length)
        end
      end
    end
  end
end