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Class: RuboCop::Cop::Style::RedundantEach

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::RuboCop::Cop::AutoCorrector, ::RuboCop::Cop::Base, ::RuboCop::ExcludeLimit, NodePattern::Macros, RuboCop::AST::Sexp
Instance Chain:
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/style/redundant_each.rb

Overview

Checks for redundant each.

Examples:

# bad
array.each.each { |v| do_something(v) }

# good
array.each { |v| do_something(v) }

# bad
array.each.each_with_index { |v, i| do_something(v, i) }

# good
array.each.with_index { |v, i| do_something(v, i) }
array.each_with_index { |v, i| do_something(v, i) }

# bad
array.each.each_with_object { |v, o| do_something(v, o) }

# good
array.each.with_object { |v, o| do_something(v, o) }
array.each_with_object { |v, o| do_something(v, o) }

Cop Safety Information:

  • This cop is unsafe, as it can produce false positives if the receiver is not an Enumerator.

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

Class Attribute Summary

::RuboCop::Cop::AutoCorrector - Extended

::RuboCop::Cop::Base - Inherited

.gem_requirements, .lint?,
.support_autocorrect?

Returns if class supports autocorrect.

.support_multiple_source?

Override if your cop should be called repeatedly for multiple investigations Between calls to on_new_investigation and on_investigation_end, the result of processed_source will remain constant.

.builtin?

Class Method Summary

::RuboCop::Cop::Base - Inherited

.autocorrect_incompatible_with

List of cops that should not try to autocorrect at the same time as this cop.

.badge

Naming.

.callbacks_needed, .cop_name, .department,
.documentation_url

Cops (other than builtin) are encouraged to implement this.

.exclude_from_registry

Call for abstract Cop classes.

.inherited,
.joining_forces

Override and return the Force class(es) you need to join.

.match?

Returns true if the cop name or the cop namespace matches any of the given names.

.new,
.requires_gem

Register a version requirement for the given gem name.

.restrict_on_send

::RuboCop::ExcludeLimit - Extended

exclude_limit

Sets up a configuration option to have an exclude limit tracked.

transform

Instance Attribute Summary

Instance Method Summary

::RuboCop::Cop::Base - Inherited

#add_global_offense

Adds an offense that has no particular location.

#add_offense

Adds an offense on the specified range (or node with an expression) Unless that offense is disabled for this range, a corrector will be yielded to provide the cop the opportunity to autocorrect the offense.

#begin_investigation

Called before any investigation.

#callbacks_needed,
#cop_config

Configuration Helpers.

#cop_name, #excluded_file?,
#external_dependency_checksum

This method should be overridden when a cop’s behavior depends on state that lives outside of these locations:

#inspect,
#message

Gets called if no message is specified when calling add_offense or add_global_offense Cops are discouraged to override this; instead pass your message directly.

#name

Alias for Base#cop_name.

#offenses,
#on_investigation_end

Called after all on_…​

#on_new_investigation

Called before all on_…​

#on_other_file

Called instead of all on_…​

#parse

There should be very limited reasons for a Cop to do it’s own parsing.

#parser_engine,
#ready

Called between investigations.

#relevant_file?, #target_rails_version, #target_ruby_version, #annotate, #apply_correction, #attempt_correction,
#callback_argument

Reserved for Cop::Cop.

#complete_investigation

Called to complete an investigation.

#correct, #current_corrector,
#current_offense_locations

Reserved for Commissioner:

#current_offenses, #currently_disabled_lines, #custom_severity, #default_severity, #disable_uncorrectable, #enabled_line?, #file_name_matches_any?, #find_message, #find_severity, #range_for_original, #range_from_node_or_range, #reset_investigation, #use_corrector

::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

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

Instance Method Details

#message(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/redundant_each.rb', line 96

def message(node)
  case node.method_name
  when :each
    MSG
  when :each_with_index
    MSG_WITH_INDEX
  when :each_with_object
    MSG_WITH_OBJECT
  end
end

#on_csend(node)

Alias for #on_send.

[ GitHub ]

  
# File 'lib/rubocop/cop/style/redundant_each.rb', line 59

alias on_csend on_send

#on_send(node) Also known as: #on_csend

[ GitHub ]

  
# File 'lib/rubocop/cop/style/redundant_each.rb', line 43

def on_send(node)
  return unless (redundant_node = redundant_each_method(node))

  range = range(node)

  add_offense(range, message: message(node)) do |corrector|
    case node.method_name
    when :each
      remove_redundant_each(corrector, range, redundant_node)
    when :each_with_index
      corrector.replace(node.loc.selector, 'with_index')
    when :each_with_object
      corrector.replace(node.loc.selector, 'with_object')
    end
  end
end

#range(node) (private)

Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity

[ GitHub ]

  
# File 'lib/rubocop/cop/style/redundant_each.rb', line 86

def range(node)
  return node.selector unless node.method?(:each)

  if node.parent&.call_type?
    node.selector.join(node.parent.loc.dot)
  else
    node.loc.dot.join(node.selector)
  end
end

#redundant_each_method(node) (private)

Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity

[ GitHub ]

  
# File 'lib/rubocop/cop/style/redundant_each.rb', line 64

def redundant_each_method(node)
  return if node.last_argument&.block_pass_type?

  if node.method?(:each) && !node.parent&.block_type?
    ancestor_node = node.each_ancestor(:send, :csend).detect do |ancestor|
      ancestor.receiver == node &&
        (RESTRICT_ON_SEND.include?(ancestor.method_name) || ancestor.method?(:reverse_each))
    end

    return ancestor_node if ancestor_node
  end

  return unless (prev_method = node.children.first)
  return if !prev_method.send_type? ||
            prev_method.parent.block_type? || prev_method.last_argument&.block_pass_type?

  detected = prev_method.method_name.to_s.start_with?('each_') unless node.method?(:each)

  prev_method if detected || prev_method.method?(:reverse_each)
end

#remove_redundant_each(corrector, range, redundant_node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/redundant_each.rb', line 107

def remove_redundant_each(corrector, range, redundant_node)
  corrector.remove(range)

  if redundant_node.method?(:each_with_index)
    corrector.replace(redundant_node.loc.selector, 'each.with_index')
  elsif redundant_node.method?(:each_with_object)
    corrector.replace(redundant_node.loc.selector, 'each.with_object')
  end
end