Class: RuboCop::Cop::Lint::HashCompareByIdentity

Inherits:
Base
  • Object
show all
Defined in:
lib/rubocop/cop/lint/hash_compare_by_identity.rb

Overview

Prefer using `Hash#compare_by_identity` than using `object_id` for hash keys.

This cop is marked as unsafe as a hash possibly can contain other keys besides `object_id`s.

Examples:

# bad
hash = {}
hash[foo.object_id] = :bar
hash.key?(baz.object_id)

# good
hash = {}.compare_by_identity
hash[foo] = :bar
hash.key?(baz)

Constant Summary collapse

RESTRICT_ON_SEND =
%i[key? has_key? fetch [] []=].freeze
MSG =
'Use `Hash#compare_by_identity` instead of using `object_id` for keys.'

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods inherited from Base

#add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #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

Instance Method Details

#id_as_hash_key?(node) ⇒ Object


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# File 'lib/rubocop/cop/lint/hash_compare_by_identity.rb', line 28

def_node_matcher :id_as_hash_key?, <<~PATTERN
  (send _ {:key? :has_key? :fetch :[] :[]=} (send _ :object_id) ...)
PATTERN

#on_send(node) ⇒ Object


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# File 'lib/rubocop/cop/lint/hash_compare_by_identity.rb', line 32

def on_send(node)
  add_offense(node) if id_as_hash_key?(node)
end