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Class: RuboCop::Cop::Lint::SafeNavigationChain

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::RuboCop::Cop::TargetRubyVersion, ::RuboCop::Cop::AutoCorrector, ::RuboCop::Cop::Base, ::RuboCop::ExcludeLimit, NodePattern::Macros, RuboCop::AST::Sexp
Instance Chain:
self, ::RuboCop::Cop::NilMethods, ::RuboCop::Cop::AllowedMethods, ::RuboCop::Cop::Base, ::RuboCop::Cop::AutocorrectLogic, ::RuboCop::Cop::IgnoredNode, ::RuboCop::Util, RuboCop::AST::Sexp
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/lint/safe_navigation_chain.rb

Overview

The safe navigation operator returns nil if the receiver is nil. If you chain an ordinary method call after a safe navigation operator, it raises NoMethodError. We should use a safe navigation operator after a safe navigation operator. This cop checks for the problem outlined above.

Examples:

# bad
x&.foo.bar
x&.foo + bar
x&.foo[bar]

# good
x&.foo&.bar
x&.foo || bar

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

Class Attribute Summary

::RuboCop::Cop::AutoCorrector - Extended

support_autocorrect?

::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.

Class Method Summary

::RuboCop::Cop::TargetRubyVersion - Extended

minimum_target_ruby_version, required_minimum_ruby_version, support_target_ruby_version?

::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

Returns a url to view this cops documentation online.
.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

::RuboCop::Cop::AllowedMethods - Included

#ignored_method?

::RuboCop::Cop::Base - Inherited

#active_support_extensions_enabled?, #always_autocorrect?, #config, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #processed_source, #string_literals_frozen_by_default?, #target_satisfies_all_gem_version_requirements?

::RuboCop::Cop::AutocorrectLogic - Included

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

Instance Method Summary

::RuboCop::Cop::NilMethods - Included

#nil_methods, #other_stdlib_methods

::RuboCop::Cop::AllowedMethods - Included

#allowed_method?, #allowed_methods, #cop_config_allowed_methods, #cop_config_deprecated_values

::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

Actually private methods.
#use_corrector

::RuboCop::Cop::AutocorrectLogic - Included

#disable_offense, #disable_offense_at_end_of_line, #disable_offense_before_and_after, #disable_offense_with_eol_or_surround_comment, #max_line_length,
#range_by_lines

Expand the given range to include all of any lines it covers.
#range_of_first_line, #range_overlaps_offense?, #string_continuation, #string_continuation?, #surrounding_heredoc, #surrounding_percent_array

::RuboCop::Cop::IgnoredNode - Included

#ignore_node, #ignored_node?, #part_of_ignored_node?, #ignored_nodes

Constructor Details

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

Instance Method Details

#add_safe_navigation_operator(offense_range:, send_node:) ⇒ String (private)

Parameters:

  • offense_range (Parser::Source::Range)
  • send_node (RuboCop::AST::SendNode)
[ GitHub ] 

  


# File 'lib/rubocop/cop/lint/safe_navigation_chain.rb', line 67



def add_safe_navigation_operator(offense_range:, send_node:)
  source =
    if brackets?(send_node)
      format(
        '%<method_name>s(%<arguments>s)%<method_chain>s',
        arguments: send_node.arguments.map(&:source).join(', '),
        method_name: send_node.method_name,
        method_chain: send_node.source_range.end.join(send_node.source_range.end).source
      )
    else
      offense_range.source
    end
  source.prepend('.') unless source.start_with?('.')
  source.prepend('&')
end


  








  

    #autocorrect(corrector, offense_range:, send_node:)   (private)
  



  

    
  





  
Parameters:





  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/safe_navigation_chain.rb', line 86



def autocorrect(corrector, offense_range:, send_node:)
  corrector.replace(
    offense_range,
    add_safe_navigation_operator(offense_range: offense_range, send_node: send_node)
  )

  corrector.wrap(send_node, '(', ')') if require_parentheses?(send_node)
end


  








  

    #bad_method?(node)  
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/safe_navigation_chain.rb', line 33



def_node_matcher :bad_method?, <<~PATTERN
  {
    (send $(csend ...) $_ ...)
    (send $({block numblock} (csend ...) ...) $_ ...)
  }
PATTERN


  








  

    #brackets?(send_node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/safe_navigation_chain.rb', line 95



def brackets?(send_node)
  send_node.method?(:[]) || send_node.method?(:[]=)
end


  








  

    #on_send(node)  
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/safe_navigation_chain.rb', line 40



def on_send(node)
  return unless require_safe_navigation?(node)

  bad_method?(node) do |safe_nav, method|
    return if nil_methods.include?(method) || PLUS_MINUS_METHODS.include?(node.method_name)

    begin_range = node.loc.dot || safe_nav.source_range.end
    location = begin_range.join(node.source_range.end)

    add_offense(location) do |corrector|
      autocorrect(corrector, offense_range: location, send_node: node)
    end
  end
end


  








  

    #require_parentheses?(send_node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/safe_navigation_chain.rb', line 99



def require_parentheses?(send_node)
  return false unless send_node.comparison_method?
  return false unless (node = send_node.parent)

  (node.respond_to?(:logical_operator?) && node.logical_operator?) ||
    (node.respond_to?(:comparison_method?) && node.comparison_method?)
end


  








  

    #require_safe_navigation?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/safe_navigation_chain.rb', line 57



def require_safe_navigation?(node)
  parent = node.parent
  return true unless parent&.and_type?

  parent.rhs != node || parent.lhs.receiver != parent.rhs.receiver
end