class RuboCop::Cop::Style::HashEachMethods
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.each { |k, unused_value| p k } # good hash.each_key { |k| p k } # bad hash.values.each { |v| p v } hash.each { |unused_key, v| p v } # good hash.each_value { |v| p v }
@example AllowedReceivers: [‘execute’]
# good execute(sql).keys.each { |v| p v } execute(sql).values.each { |v| p v }
Constants
- ARRAY_CONVERTER_METHODS
- MSG
- UNUSED_BLOCK_ARG_MSG
Public Instance Methods
check_unused_block_args(node, key, value)
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rubocop:disable Metrics/AbcSize
# 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
on_block(node)
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# 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
Also aliased as: on_numblock
on_block_pass(node)
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rubocop:enable Metrics/AbcSize
# 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
Private Instance Methods
check_argument(variable)
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# File lib/rubocop/cop/style/hash_each_methods.rb, line 186 def check_argument(variable) return unless variable.block_argument? (@block_args ||= []).push(variable) end
correct_args(node, corrector)
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# 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
correct_implicit(node, corrector, method_name)
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# 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
correct_key_value_each(node, corrector)
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# 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
format_message(method_name, current)
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# 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
handleable?(node)
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# 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
kv_range(outer_node)
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# 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
message(prefer, method_name, unused_code)
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# 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
register_each_args_offense(node, message, prefer, unused_range)
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# 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
register_kv_offense(target, method)
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# 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
register_kv_with_block_pass_offense(node, target, method)
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# 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
root_receiver(node)
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# 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
unused_block_arg_exist?(node, block_arg)
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# 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
use_array_converter_method_as_preceding?(node)
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# 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
used?(arg)
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# 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