Class: RuboCop::Cop::Style::RedundantArrayFlatten

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

Overview

Checks for redundant calls of ‘Array#flatten`.

‘Array#join` joins nested arrays recursively, so flattening an array beforehand is redundant.

Examples:

# bad
x.flatten.join
x.flatten(1).join

# good
x.join

Constant Summary collapse

MSG = 
'Remove the redundant `flatten`.'
RESTRICT_ON_SEND = 
%i[flatten].freeze

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, #always_autocorrect?, autocorrect_incompatible_with, badge, #begin_investigation, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #cop_config, #cop_name, cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, #inspect, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #parser_engine, #ready, #relevant_file?, requires_gem, #string_literals_frozen_by_default?, support_autocorrect?, support_multiple_source?, #target_gem_version, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

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

#flatten_join?(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/redundant_array_flatten.rb', line 34

def_node_matcher :flatten_join?, <<~PATTERN
  (call (call !nil? :flatten _?) :join (nil)?)
PATTERN

#on_send(node) ⇒ Object Also known as: on_csend 



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# File 'lib/rubocop/cop/style/redundant_array_flatten.rb', line 38

def on_send(node)
  return unless flatten_join?(node.parent)

  range = node.loc.dot.begin.join(node.source_range.end)
  add_offense(range) do |corrector|
    corrector.remove(range)
  end
end