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.

NOTE

Because of a bug in Ruby 3.3.0, when a block is referenced inside of another block, no offense will be registered until Ruby 3.4:

source,ruby

---

def foo(&block)

# Using an anonymous block would be a syntax error on Ruby 3.3.0
block_method { bar(&block) }

end

---

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

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 included from RangeHelp

RangeHelp::BYTE_ORDER_MARK, RangeHelp::NOT_GIVEN

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

maximum_target_ruby_version, minimum_target_ruby_version, required_maximum_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_gem_version, #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 155

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 159

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(:call, :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