Class: RuboCop::Cop::Style::ArgumentsForwarding

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector, TargetRubyVersion
Includes:
RangeHelp
Defined in:
lib/rubocop/cop/style/arguments_forwarding.rb

Overview

In Ruby 2.7, arguments forwarding has been added.

This cop identifies places where `do_something(*args, &block)` can be replaced by `do_something(…)`.

Examples:

# bad
def foo(*args, &block)
  bar(*args, &block)
end

# bad
def foo(*args, **kwargs, &block)
  bar(*args, **kwargs, &block)
end

# good
def foo(...)
  bar(...)
end

AllowOnlyRestArgument: true (default)

# good
def foo(*args)
  bar(*args)
end

AllowOnlyRestArgument: false

# bad
# The following code can replace the arguments with `...`,
# but it will change the behavior. Because `...` forwards block also.
def foo(*args)
  bar(*args)
end

Constant Summary collapse

MSG =
'Use arguments forwarding.'

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods included from TargetRubyVersion

minimum_target_ruby_version, required_minimum_ruby_version, support_target_ruby_version?

Methods inherited from Base

#add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

silence_warnings

Constructor Details

This class inherits a constructor from RuboCop::Cop::Base

Instance Method Details

#forwarding_method_arguments?(node, rest_name, block_name, kwargs_name) ⇒ Object


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

def_node_matcher :forwarding_method_arguments?, <<~PATTERN
  {
    (send _ _
      (splat (lvar %1))
      (block-pass (lvar %2)))
    (send _ _
      (splat (lvar %1))
      (hash (kwsplat (lvar %3)))
      (block-pass (lvar %2)))
  }
PATTERN

#on_def(node) ⇒ Object Also known as: on_defs


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# File 'lib/rubocop/cop/style/arguments_forwarding.rb', line 73

def on_def(node)
  return unless node.body
  return unless (rest_args_name, args = use_rest_arguments?(node.arguments))

  node.each_descendant(:send) do |send_node|
    kwargs_name, block_name = extract_argument_names_from(args)

    next unless forwarding_method?(send_node, rest_args_name, kwargs_name, block_name) &&
                all_lvars_as_forwarding_method_arguments?(node, send_node)

    register_offense_to_forwarding_method_arguments(send_node)
    register_offense_to_method_definition_arguments(node)
  end
end

#only_rest_arguments?(node, name) ⇒ Object


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

def_node_matcher :only_rest_arguments?, <<~PATTERN
  (send _ _ (splat (lvar %1)))
PATTERN

#use_rest_arguments?(node) ⇒ Object


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

def_node_matcher :use_rest_arguments?, <<~PATTERN
  (args (restarg $_) $...)
PATTERN