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

Inherits:

Base

• Object
• Base
• RuboCop::Cop::Style::ArgumentsForwarding

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(…)`.

In Ruby 3.1, anonymous block forwarding has been added.

This cop identifies places where ‘do_something(&block)` can be replaced by `do_something(&)`; if desired, this functionality can be disabled by setting `UseAnonymousForwarding: false`.

In Ruby 3.2, anonymous args/kwargs forwarding has been added.

This cop also identifies places where ‘use_args(*args)`/`use_kwargs(**kwargs)` can be replaced by `use_args(*)`/`use_kwargs(**)`; if desired, this functionality can be disabled by setting `UseAnonymousForwarding: false`.

And this cop has ‘RedundantRestArgumentNames`, `RedundantKeywordRestArgumentNames`, and `RedundantBlockArgumentNames` options. This configuration is a list of redundant names that are sufficient for anonymizing meaningless naming.

Meaningless names that are commonly used can be anonymized by default: e.g., ‘*args`, `**options`, `&block`, and so on.

Names not on this list are likely to be meaningful and are allowed by default.

This cop handles not only method forwarding but also forwarding to ‘super`.

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

UseAnonymousForwarding: true (default, only relevant for Ruby >= 3.2)

# bad
def foo(*args, **kwargs, &block)
  args_only(*args)
  kwargs_only(**kwargs)
  block_only(&block)
end

# good
def foo(*, **, &)
  args_only(*)
  kwargs_only(**)
  block_only(&)
end

UseAnonymousForwarding: false (only relevant for Ruby >= 3.2)

# good
def foo(*args, **kwargs, &block)
  args_only(*args)
  kwargs_only(**kwargs)
  block_only(&block)
end

AllowOnlyRestArgument: true (default, only relevant for Ruby < 3.2)

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

def foo(**kwargs)
  bar(**kwargs)
end

AllowOnlyRestArgument: false (only relevant for Ruby < 3.2)

# 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

def foo(**kwargs)
  bar(**kwargs)
end

RedundantRestArgumentNames: [‘args’, ‘arguments’] (default)

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

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

RedundantKeywordRestArgumentNames: [‘kwargs’, ‘options’, ‘opts’] (default)

# bad
def foo(**kwargs)
  bar(**kwargs)
end

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

RedundantBlockArgumentNames: [‘blk’, ‘block’, ‘proc’] (default)

# bad - But it is good with `EnforcedStyle: explicit` set for `Naming/BlockForwarding`.
def foo(&block)
  bar(&block)
end

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

Defined Under Namespace

Classes: SendNodeClassifier

Constant Summary

FORWARDING_LVAR_TYPES =

%i[splat kwsplat block_pass].freeze

ADDITIONAL_ARG_TYPES =

%i[lvar arg].freeze

FORWARDING_MSG =

'Use shorthand syntax `...` for arguments forwarding.'

ARGS_MSG =

'Use anonymous positional arguments forwarding (`*`).'

KWARGS_MSG =

'Use anonymous keyword arguments forwarding (`**`).'

BLOCK_MSG =

'Use anonymous block arguments forwarding (`&`).'

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Class Method Summary

• .autocorrect_incompatible_with ⇒ Object

Instance Method Summary

• #on_def(node) ⇒ Object (also: #on_defs)

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

#active_support_extensions_enabled?, #add_global_offense, #add_offense, #always_autocorrect?, badge, #begin_investigation, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #cop_config, cop_name, #cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, #inspect, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #parser_engine, #ready, #relevant_file?, requires_gem, #string_literals_frozen_by_default?, 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?, #autocorrect_with_disable_uncorrectable?, #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

Class Method Details

.autocorrect_incompatible_with ⇒ Object

# File 'lib/rubocop/cop/style/arguments_forwarding.rb', line 142

def self.autocorrect_incompatible_with
  [Naming::BlockForwarding]
end

Instance Method Details

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

# File 'lib/rubocop/cop/style/arguments_forwarding.rb', line 146

def on_def(node)
  return unless node.body

  restarg, kwrestarg, blockarg = extract_forwardable_args(node.arguments)
  forwardable_args = redundant_forwardable_named_args(restarg, kwrestarg, blockarg)
  send_nodes = node.each_descendant(:send, :csend, :super, :yield).to_a

  send_classifications = classify_send_nodes(
    node, send_nodes, non_splat_or_block_pass_lvar_references(node.body), forwardable_args
  )

  return if send_classifications.empty?

  if only_forwards_all?(send_classifications)
    add_forward_all_offenses(node, send_classifications, forwardable_args)
  elsif target_ruby_version >= 3.2
    add_post_ruby_32_offenses(node, send_classifications, forwardable_args)
  end
end