Class: RuboCop::Cop::Style::MapCompactWithConditionalBlock

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

Overview

Prefer ‘select` or `reject` over `map { … }.compact`.

Examples:


# bad
array.map { |e| some_condition? ? e : next }.compact

# bad
array.map do |e|
  if some_condition?
    e
  else
    next
  end
end.compact

# bad
array.map do |e|
  next if some_condition?

  e
end.compact

# bad
array.map do |e|
  e if some_condition?
end.compact

# good
array.select { |e| some_condition? }

# good
array.reject { |e| some_condition? }

Constant Summary collapse

MSG = 
'Replace `map { ... }.compact` with `%<method>s`.'

Constants inherited from Base

Base::RESTRICT_ON_SEND

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, 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?, #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

#map_and_compact?(node) ⇒ Object 


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# File 'lib/rubocop/cop/style/map_compact_with_conditional_block.rb', line 46

def_node_matcher :map_and_compact?, <<~RUBY
  (send
    (block
      (send _ :map)
      (args
        $(arg _))
      {
        (if $_ $(lvar _) {next nil?})
        (if $_ {next nil?} $(lvar _))
        (if $_ (next $(lvar _)) {next nil nil?})
        (if $_ {next nil nil?} (next $(lvar _)))
        (begin
          {
            (if $_ next nil?)
            (if $_ nil? next)
          }
          $(lvar _))
        (begin
          {
            (if $_ (next $(lvar _)) nil?)
            (if $_ nil? (next $(lvar _)))
          }
          (nil))
      }) :compact)
RUBY

#on_send(node) ⇒ Object 


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# File 'lib/rubocop/cop/style/map_compact_with_conditional_block.rb', line 72

def on_send(node)
  map_and_compact?(node) do |block_argument_node, condition_node, return_value_node|
    return unless returns_block_argument?(block_argument_node, return_value_node)
    return if condition_node.parent.elsif?

    method = truthy_branch?(return_value_node) ? 'select' : 'reject'
    range = range(node)

    add_offense(range, message: format(MSG, method: method)) do |corrector|
      corrector.replace(
        range,
        "#{method} { |#{block_argument_node.source}| #{condition_node.source} }"
      )
    end
  end
end