# frozen_string_literal: true module RuboCop module Cop module Metrics # Checks for excessive nesting of conditional and looping constructs. # # You can configure if blocks are considered using the `CountBlocks` and `CountModifierForms` # options. When both are set to `false` (the default) blocks and modifier forms are not # counted towards the nesting level. Set them to `true` to include these in the nesting level # calculation as well. # # The maximum level of nesting allowed is configurable. class BlockNesting < Base NESTING_BLOCKS = %i[case case_match if while while_post until until_post for resbody].freeze exclude_limit 'Max' def on_new_investigation return if processed_source.blank? max = cop_config['Max'] check_nesting_level(processed_source.ast, max, 0) end private def check_nesting_level(node, max, current_level) if consider_node?(node) current_level += 1 if count_if_block?(node) if current_level > max self.max = current_level unless part_of_ignored_node?(node) add_offense(node, message: message(max)) { ignore_node(node) } end end end node.each_child_node do |child_node| check_nesting_level(child_node, max, current_level) end end def count_if_block?(node) return true unless node.if_type? return false if node.elsif? return count_modifier_forms? if node.modifier_form? true end def consider_node?(node) return true if NESTING_BLOCKS.include?(node.type) count_blocks? && (node.block_type? || node.numblock_type?) end def message(max) "Avoid more than #{max} levels of block nesting." end def count_blocks? cop_config.fetch('CountBlocks', false) end def count_modifier_forms? cop_config.fetch('CountModifierForms', false) end end end end end