class RuboCop::Cop::Lint::NextWithoutAccumulator

end
acc + i
next acc if i.odd?
result = (1..4).reduce(0) do |acc, i|
# good
@example
end
acc + i
next if i.odd?
result = (1..4).reduce(0) do |acc, i|
# bad
@example
Don’t omit the accumulator when calling ‘next` in a `reduce` block.

def on_block(node) 

def on_block(node)
  on_block_body_of_reduce(node) do |body|
    void_next = body.each_node(:next).find do |n|
      n.children.empty? && parent_block_node(n) == node
    end
    add_offense(void_next) if void_next
  end
end

def on_numblock(node) 

def on_numblock(node)
  on_numblock_body_of_reduce(node) do |body|
    void_next = body.each_node(:next).find do |n|
      n.children.empty? && parent_numblock_node(n) == node
    end
    add_offense(void_next) if void_next
  end
end

def parent_block_node(node) 

def parent_block_node(node)
  node.each_ancestor(:block).first
end

def parent_numblock_node(node) 

def parent_numblock_node(node)
  node.each_ancestor(:numblock).first
end