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Class: RuboCop::Cop::Style::HashSlice

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

Overview

Checks for usages of Hash#reject, Hash#select, and Hash#filter methods that can be replaced with Hash#slice method.

This cop should only be enabled on Ruby version 2.5 or higher. (Hash#slice was added in Ruby 2.5.)

For safe detection, it is limited to commonly used string and symbol comparisons when using == or !=.

This cop doesn’t check for Hash#delete_if and Hash#keep_if because they modify the receiver.

Examples:

# bad
{foo: 1, bar: 2, baz: 3}.select {|k, v| k == :bar }
{foo: 1, bar: 2, baz: 3}.reject {|k, v| k != :bar }
{foo: 1, bar: 2, baz: 3}.filter {|k, v| k == :bar }
{foo: 1, bar: 2, baz: 3}.select {|k, v| k.eql?(:bar) }

# bad
{foo: 1, bar: 2, baz: 3}.select {|k, v| %i[bar].include?(k) }
{foo: 1, bar: 2, baz: 3}.reject {|k, v| !%i[bar].include?(k) }
{foo: 1, bar: 2, baz: 3}.filter {|k, v| %i[bar].include?(k) }

# bad
{foo: 1, bar: 2, baz: 3}.select {|k, v| !%i[bar].exclude?(k) }
{foo: 1, bar: 2, baz: 3}.reject {|k, v| %i[bar].exclude?(k) }

# bad
{foo: 1, bar: 2, baz: 3}.select {|k, v| k.in?(%i[bar]) }
{foo: 1, bar: 2, baz: 3}.reject {|k, v| !k.in?(%i[bar]) }

# good
{foo: 1, bar: 2, baz: 3}.slice(:bar)

Cop Safety Information:

  • This cop is unsafe because it cannot be guaranteed that the receiver is a Hash or responds to the replacement method.

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::RangeHelp - Included

BYTE_ORDER_MARK, NOT_GIVEN

::RuboCop::Cop::HashSubset - Included

ACTIVE_SUPPORT_SUBSET_METHODS, MSG, RESTRICT_ON_SEND, SUBSET_METHODS

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

maximum_target_ruby_version, minimum_target_ruby_version, required_maximum_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::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::HashSubset - Included

#block_with_first_arg_check?,
#on_csend

Alias for HashSubset#on_send.
#on_send, #decorate_source, #except_key, #except_key_source, #extract_body_if_negated, #extract_offense, #extracts_hash_subset?, #included?, #not_included?, #offense_range, #preferred_method_name, #safe_to_register_offense?, #semantically_except_method?, #semantically_slice_method?, #semantically_subset_method?, #supported_subset_method?

::RuboCop::Cop::RangeHelp - Included

#add_range, #column_offset_between,
#contents_range

A range containing only the contents of a literal with delimiters (e.g.
#directions,
#effective_column

Returns the column attribute of the range, except if the range is on the first line and there’s a byte order mark at the beginning of that line, in which case 1 is subtracted from the column value.
#final_pos, #move_pos, #move_pos_str, #range_between, #range_by_whole_lines, #range_with_comments, #range_with_comments_and_lines, #range_with_surrounding_comma, #range_with_surrounding_space, #source_range

::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_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

#disable_offense, #disable_offense_at_end_of_line, #disable_offense_before_and_after, #disable_offense_with_eol_or_surround_comment, #heredoc_range, #max_line_length, #multiline_ranges, #multiline_string?,
#range_by_lines

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

#preferred_method_name (private)

[ GitHub ] 

  


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



def preferred_method_name
  'slice'
end


  








  

    #semantically_subset_method?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/style/hash_slice.rb', line 55



def semantically_subset_method?(node)
  semantically_slice_method?(node)
end