Class: RuboCop::Cop::Style::HashEachMethods

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 79

def check_unused_block_args(node, key, value)
  return if node.body.nil?

  value_unused = unused_block_arg_exist?(node, value)
  key_unused = unused_block_arg_exist?(node, key)
  return if value_unused && key_unused

  if value_unused
    message = message('each_key', node.method_name, value.source)
    unused_range = key.source_range.end.join(value.source_range.end)

    register_each_args_offense(node, message, 'each_key', unused_range)
  elsif key_unused
    message = message('each_value', node.method_name, key.source)
    unused_range = key.source_range.begin.join(value.source_range.begin)

    register_each_args_offense(node, message, 'each_value', unused_range)
  end
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 210

def correct_args(node, corrector)
  args = node.parent.arguments
  name, = *args.children.find { |arg| used?(arg) }

  corrector.replace(args, "|#{name}|")
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 196

def correct_implicit(node, corrector, method_name)
  corrector.replace(node, method_name)
  correct_args(node, corrector)
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 201

def correct_key_value_each(node, corrector)
  receiver = node.receiver.receiver
  name = "each_#{node.receiver.method_name.to_s.chop}"
  return correct_implicit(node, corrector, name) unless receiver

  new_source = receiver.source + "#{node.loc.dot.source}#{name}"
  corrector.replace(node, new_source)
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 51

def_node_matcher :each_arguments, <<~PATTERN
  (block (call _ :each)(args $_key $_value) ...)
PATTERN

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 182

def format_message(method_name, current)
  format(MSG, prefer: "each_#{method_name[0..-2]}", current: current)
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 108

def handleable?(node)
  return false if use_array_converter_method_as_preceding?(node)
  return false unless (root_receiver = root_receiver(node))
  return false if hash_mutated?(node, root_receiver)

  !root_receiver.literal? || root_receiver.hash_type?
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 61

def_node_matcher :hash_mutated?, <<~PATTERN
  `(send %1 :[]= ...)
PATTERN

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 46

def_node_matcher :kv_each, <<~PATTERN
  ({block numblock} $(call (call _ ${:keys :values}) :each) ...)
PATTERN

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 56

def_node_matcher :kv_each_with_block_pass, <<~PATTERN
  (call $(call _ ${:keys :values}) :each (block_pass (sym _)))
PATTERN

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 217

def kv_range(outer_node)
  outer_node.receiver.loc.selector.join(outer_node.loc.selector)
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 139

def message(prefer, method_name, unused_code)
  format(
    UNUSED_BLOCK_ARG_MSG, prefer: prefer, current: method_name, unused_code: unused_code
  )
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 65

def on_block(node)
  return unless handleable?(node)

  kv_each(node) do |target, method|
    register_kv_offense(target, method) and return
  end

  return unless (key, value = each_arguments(node))

  check_unused_block_args(node, key, value)
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 100

def on_block_pass(node)
  kv_each_with_block_pass(node.parent) do |target, method|
    register_kv_with_block_pass_offense(node, target, method)
  end
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 76

alias on_numblock on_block

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 145

def register_each_args_offense(node, message, prefer, unused_range)
  add_offense(node, message: message) do |corrector|
    corrector.replace(node.send_node.loc.selector, prefer)
    corrector.remove(unused_range)
  end
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 116

def register_kv_offense(target, method)
  return unless (parent_receiver = target.receiver.receiver)
  return if allowed_receiver?(parent_receiver)

  current = target.receiver.loc.selector.join(target.source_range.end).source

  add_offense(kv_range(target), message: format_message(method, current)) do |corrector|
    correct_key_value_each(target, corrector)
  end
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 152

def register_kv_with_block_pass_offense(node, target, method)
  return unless (parent_receiver = node.parent.receiver.receiver)
  return if allowed_receiver?(parent_receiver)

  range = target.loc.selector.join(node.parent.loc.selector.end)

  add_offense(range, message: format_message(method, range.source)) do |corrector|
    corrector.replace(range, "each_#{method[0..-2]}")
  end
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 173

def root_receiver(node)
  receiver = node.receiver
  if receiver&.receiver
    root_receiver(receiver)
  else
    receiver
  end
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 127

def unused_block_arg_exist?(node, block_arg)
  lvar_sources = node.body.each_descendant(:lvar).map(&:source)

  if block_arg.mlhs_type?
    block_arg.each_descendant(:arg, :restarg).all? do |block_arg|
      lvar_sources.none?(block_arg.source.delete_prefix('*'))
    end
  else
    lvar_sources.none?(block_arg.source.delete_prefix('*'))
  end
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 163

def use_array_converter_method_as_preceding?(node)
  return false unless (preceding_method = node.children.first.children.first)
  unless preceding_method.call_type? ||
         preceding_method.block_type? || preceding_method.numblock_type?
    return false
  end

  ARRAY_CONVERTER_METHODS.include?(preceding_method.method_name)
end

# File 'lib/rubocop/cop/style/hash_each_methods.rb', line 192

def used?(arg)
  @block_args.find { |var| var.declaration_node.loc == arg.loc }.used?
end