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# frozen_string_literal: true
module RuboCop
module Cop
# Checks for return inside blocks.
# For more information see: https://gitlab.com/gitlab-org/gitlab-foss/issues/42889
#
# @example
# # bad
# call do
# return if something
#
# do_something_else
# end
#
# # good
# call do
# break if something
#
# do_something_else
# end
#
class AvoidReturnFromBlocks < RuboCop::Cop::Base
MSG = 'Do not return from a block, use next or break instead.'
DEF_METHODS = %i[define_method lambda].freeze
ALLOWLISTED_METHODS = %i[each each_filename times loop].freeze
def on_block(node)
block_body = node.body
return unless block_body
return unless top_block?(node)
block_body.each_node(:return) do |return_node|
next if parent_blocks(node, return_node).all? { |block_node| allowlisted?(block_node) }
add_offense(return_node)
end
end
private
def top_block?(node)
current_node = node
top_block = nil
while current_node && current_node.type != :def
top_block = current_node if current_node.type == :block
current_node = current_node.parent
end
top_block == node
end
def parent_blocks(node, current_node)
blocks = []
until node == current_node || def?(current_node)
blocks << current_node if current_node.type == :block
current_node = current_node.parent
end
blocks << node if node == current_node && !def?(node)
blocks
end
def def?(node)
node.type == :def || node.type == :defs ||
(node.type == :block && DEF_METHODS.include?(node.method_name))
end
def allowlisted?(block_node)
ALLOWLISTED_METHODS.include?(block_node.method_name)
end
end
end
end
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