# frozen_string_literal: true module RuboCop module Cop module Style # Checks for uses of `each_key` and `each_value` Hash methods. # # NOTE: If you have an array of two-element arrays, you can put # parentheses around the block arguments to indicate that you're not # working with a hash, and suppress RuboCop offenses. # # @safety # This cop is unsafe because it cannot be guaranteed that the receiver # is a `Hash`. The `AllowedReceivers` configuration can mitigate, # but not fully resolve, this safety issue. # # @example # # bad # hash.keys.each { |k| p k } # hash.values.each { |v| p v } # # # good # hash.each_key { |k| p k } # hash.each_value { |v| p v } # # @example AllowedReceivers: ['execute'] # # good # execute(sql).keys.each { |v| p v } # execute(sql).values.each { |v| p v } class HashEachMethods < Base include Lint::UnusedArgument extend AutoCorrector MSG = 'Use `%s` instead of `%s`.' # @!method kv_each(node) def_node_matcher :kv_each, <<~PATTERN (block $(send (send _ ${:keys :values}) :each) ...) PATTERN def on_block(node) register_kv_offense(node) end private def register_kv_offense(node) kv_each(node) do |target, method| parent_receiver = target.receiver.receiver return unless parent_receiver return if allowed_receiver?(parent_receiver) msg = format(message, prefer: "each_#{method[0..-2]}", current: "#{method}.each") add_offense(kv_range(target), message: msg) do |corrector| correct_key_value_each(target, corrector) end end end def check_argument(variable) return unless variable.block_argument? (@block_args ||= []).push(variable) end def used?(arg) @block_args.find { |var| var.declaration_node.loc == arg.loc }.used? end def correct_implicit(node, corrector, method_name) corrector.replace(node, method_name) correct_args(node, corrector) end 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 + ".#{name}" corrector.replace(node, new_source) end def correct_args(node, corrector) args = node.parent.arguments name, = *args.children.find { |arg| used?(arg) } corrector.replace(args, "|#{name}|") end def kv_range(outer_node) outer_node.receiver.loc.selector.join(outer_node.loc.selector) end def allowed_receiver?(receiver) receiver_name = receiver.send_type? ? receiver.method_name.to_s : receiver.source allowed_receivers.include?(receiver_name) end def allowed_receivers cop_config.fetch('AllowedReceivers', []) end end end end end