class RuboCop::Cop::Style::CombinableLoops


end
each_slice(3) { |slice| do_something(slice) }
each_slice(2) { |slice| do_something(slice) }
def method
# good
end
end
do_something_else(item)
do_something(item)
for item in items do
def method
# good
end
end
do_something_else(item)
for item in items do
end
do_something(item)
for item in items do
def method
# bad
end
end
do_something_else(item)
do_something(item)
items.each do |item|
def method
# good
end
end
do_something_else(item)
items.each do |item|
end
do_something(item)
items.each do |item|
def method
# bad
@example
second loop depends on; these two aren’t combinable.
The cop is unsafe, because the first loop might modify state that the
@safety
will make the code more efficient and more concise.
can be combined into a single loop. It is very likely that combining them
Checks for places where multiple consecutive loops over the same data

def collection_looping_method?(node) 

def collection_looping_method?(node)
  method_name = node.method_name
  method_name.start_with?('each') || method_name.end_with?('_each')
end

def combine_with_left_sibling(corrector, node) 

def combine_with_left_sibling(corrector, node)
  corrector.remove(node.left_sibling.body.source_range.end.join(node.left_sibling.loc.end))
  corrector.remove(node.source_range.begin.join(node.body.source_range.begin))
  correct_end_of_block(corrector, node)
end

def correct_end_of_block(corrector, node) 

def correct_end_of_block(corrector, node)
  return unless node.left_sibling.respond_to?(:braces?)
  return if node.right_sibling&.block_type? || node.right_sibling&.numblock_type?
  end_of_block = node.left_sibling.braces? ? '}' : ' end'
  corrector.remove(node.loc.end)
  corrector.insert_before(node.source_range.end, end_of_block)
end

def on_block(node) 

def on_block(node)
  return unless node.parent&.begin_type?
  return unless collection_looping_method?(node)
  return unless same_collection_looping_block?(node, node.left_sibling)
  return unless node.body && node.left_sibling.body
  add_offense(node) do |corrector|
    combine_with_left_sibling(corrector, node)
  end
end

def on_for(node) 

def on_for(node)
  return unless node.parent&.begin_type?
  return unless same_collection_looping_for?(node, node.left_sibling)
  add_offense(node) do |corrector|
    combine_with_left_sibling(corrector, node)
  end
end

def same_collection_looping_block?(node, sibling) 

def same_collection_looping_block?(node, sibling)
  return false if sibling.nil? || (!sibling.block_type? && !sibling.numblock_type?)
  sibling.method?(node.method_name) &&
    sibling.receiver == node.receiver &&
    sibling.send_node.arguments == node.send_node.arguments
end

def same_collection_looping_for?(node, sibling) 

def same_collection_looping_for?(node, sibling)
  sibling&.for_type? && node.collection == sibling.collection
end