Class: RuboCop::Cop::Lint::HashNewWithKeywordArgumentsAsDefault
| 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: 
        
          self,
           
      ::RuboCop::Cop::Base,
          ::RuboCop::Cop::AutocorrectLogic,
          ::RuboCop::Cop::IgnoredNode,
          ::RuboCop::Util,
          RuboCop::AST::Sexp
         | 
    |
| Inherits: | 
        RuboCop::Cop::Base
        
  | 
    
| Defined in: | lib/rubocop/cop/lint/hash_new_with_keyword_arguments_as_default.rb | 
Overview
Checks for the deprecated use of keyword arguments as a default in Hash.new.
This usage raises a warning in Ruby 3.3 and results in an error in Ruby 3.4. In Ruby 3.4, keyword arguments will instead be used to change the behavior of a hash. For example, the capacity option can be passed to create a hash with a certain size if you know it in advance, for better performance.
| 
 Note 
 | 
The following corner case may result in a false negative when upgrading from Ruby 3.3 or earlier, but it is intentionally not detected to respect the expected usage in Ruby 3.4. | 
Hash.new(capacity: 42)
Constant Summary
- 
    MSG =
    
# File 'lib/rubocop/cop/lint/hash_new_with_keyword_arguments_as_default.rb', line 32'Use a hash literal instead of keyword arguments.' - 
    RESTRICT_ON_SEND =
    
# File 'lib/rubocop/cop/lint/hash_new_with_keyword_arguments_as_default.rb', line 33%i[new].freeze
 
::RuboCop::Cop::Base - Inherited
  
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   | 
    
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 | 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::Base - Inherited
::RuboCop::Cop::AutocorrectLogic - Included
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   | 
    
| #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_gem_version | Returns a gems locked versions (i.e.  | 
    
| #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
::RuboCop::Cop::IgnoredNode - Included
Constructor Details
This class inherits a constructor from RuboCop::Cop::Base
Instance Method Details
#hash_new(node)
[ GitHub ]# File 'lib/rubocop/cop/lint/hash_new_with_keyword_arguments_as_default.rb', line 36
def_node_matcher :hash_new, <<~PATTERN (send (const {nil? (cbase)} :Hash) :new $[hash !braces?]) PATTERN
#on_send(node)
[ GitHub ]# File 'lib/rubocop/cop/lint/hash_new_with_keyword_arguments_as_default.rb', line 40
def on_send(node) return unless (first_argument = hash_new(node)) if first_argument.pairs.one? key = first_argument.pairs.first.key return if key.respond_to?(:value) && key.value == :capacity end add_offense(first_argument) do |corrector| corrector.wrap(first_argument, '{', '}') end end