Class: RuboCop::Cop::Style::CollectionCompact

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
RangeHelp
Defined in:
lib/rubocop/cop/style/collection_compact.rb

Overview

This cop checks for places where custom logic on rejection nils from arrays and hashes can be replaced with ‘Array,Hash#compact,compact!`.

It is marked as unsafe by default because false positives may occur in the nil check of block arguments to the receiver object. For example, ‘[[1, 2], [3, nil]].reject { |first, second| second.nil? }` and `[[1, 2], [3, nil]].compact` are not compatible. This will work fine when the receiver is a hash object.

Examples:

# bad
array.reject { |e| e.nil? }
array.select { |e| !e.nil? }

# good
array.compact

# bad
hash.reject! { |k, v| v.nil? }
hash.select! { |k, v| !v.nil? }

# good
hash.compact!

Constant Summary collapse

MSG = 
'Use `%<good>s` instead of `%<bad>s`.'
RESTRICT_ON_SEND = 
%i[reject reject! select select!].freeze

Constants included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

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, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

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

add_parentheses, args_begin, args_end, begins_its_line?, comment_line?, comment_lines?, double_quotes_required?, escape_string, first_part_of_call_chain, indent, interpret_string_escapes, line_range, needs_escaping?, on_node, parentheses?, same_line?, to_string_literal, to_supported_styles, trim_string_interporation_escape_character

Methods included from PathUtil

absolute?, hidden_dir?, hidden_file?, hidden_file_in_not_hidden_dir?, match_path?, maybe_hidden_file?, relative_path, smart_path

Constructor Details

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

Instance Method Details

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/collection_compact.rb', line 57

def on_send(node)
  block_node = node.parent
  return unless block_node&.block_type?

  return unless (method_name, args, receiver =
                   reject_method?(block_node) || select_method?(block_node))

  return unless args.last.source == receiver.source

  range = offense_range(node, block_node)
  good = good_method_name(method_name)
  message = format(MSG, good: good, bad: range.source)

  add_offense(range, message: message) do |corrector|
    corrector.replace(range, good)
  end
end