Class: RuboCop::Cop::Style::WordArray

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


Checks for array literals made up of word-like strings, that are not using the %w() syntax.

Alternatively, it can check for uses of the %w() syntax, in projects which do not want to include that syntax.

When using the percent style, %w() arrays containing a space will be registered as offenses.

Configuration option: MinSize If set, arrays with fewer elements than this value will not trigger the cop. For example, a MinSize of 3 will not enforce a style on an array of 2 or fewer elements.


EnforcedStyle: percent (default)

# good
%w[foo bar baz]

# bad
['foo', 'bar', 'baz']

# bad (contains spaces)
%w[foo\ bar baz\ quux]

# bad
  ['one', 'One'],
  ['two', 'Two']

# good
  %w[one One],
  %w[two Two]

# good (2d array containing spaces)
  ['one', 'One'],
  ['two', 'Two'],
  ['forty two', 'Forty Two']

EnforcedStyle: brackets

# good
['foo', 'bar', 'baz']

# bad
%w[foo bar baz]

# good (contains spaces)
['foo bar', 'baz quux']

# good
  ['one', 'One'],
  ['two', 'Two']

# bad
  %w[one One],
  %w[two Two]

Constant Summary

::RuboCop::Cop::Base - Inherited


::RuboCop::Cop::ConfigurableEnforcedStyle - Included


Class Attribute Summary

::RuboCop::Cop::AutoCorrector - Extended

::RuboCop::Cop::Base - Inherited

.gem_requirements, .lint?,

Returns if class supports autocorrect.


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::Base - Inherited


List of cops that should not try to autocorrect at the same time as this cop.



.callbacks_needed, .cop_name, .department,

Returns an url to view this cops documentation online.


Call for abstract Cop classes.


Override and return the Force class(es) you need to join.


Returns true if the cop name or the cop namespace matches any of the given names.


Register a version requirement for the given gem name.


::RuboCop::ExcludeLimit - Extended


Sets up a configuration option to have an exclude limit tracked.


Instance Attribute Summary

Instance Method Summary

::RuboCop::Cop::PercentArray - Included

#allowed_bracket_array?, #build_bracketed_array_with_appropriate_whitespace, #build_message_for_bracketed_array, #check_bracketed_array, #check_percent_array, #comments_in_array?,

Override to determine values that are invalid in a percent array.


Ruby does not allow percent arrays in an ambiguous block context.


Provides whitespace between elements for building a bracketed array.


Provides leading whitespace for building a bracketed array.


Provides trailing whitespace for building a bracketed array.

::RuboCop::Cop::ConfigurableEnforcedStyle - Included

::RuboCop::Cop::ArraySyntax - Included

::RuboCop::Cop::ArrayMinSize - Included

::RuboCop::Cop::Base - Inherited


Adds an offense that has no particular location.


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.


Called before any investigation.


Configuration Helpers.

#cop_name, #excluded_file?,

This method should be overridden when a cop’s behavior depends on state that lives outside of these locations:


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.


Alias for Base#cop_name.


Called after all on_…​


Called before all on_…​


Called instead of all on_…​


There should be very limited reasons for a Cop to do it’s own parsing.


Called between investigations.

#relevant_file?, #target_rails_version, #target_ruby_version, #annotate, #apply_correction, #attempt_correction,

Reserved for Cop::Cop.


Called to complete an investigation.

#correct, #current_corrector,

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,

Actually private methods.


::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

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

Class Attribute Details

.largest_brackets (rw)

[ GitHub ]

# File 'lib/rubocop/cop/style/word_array.rb', line 82

attr_accessor :largest_brackets

Instance Method Details

#build_bracketed_array(node) (private)

[ GitHub ]

# File 'lib/rubocop/cop/style/word_array.rb', line 138

def build_bracketed_array(node)
  return '[]' if node.children.empty?

  words = node.children.map do |word|
    if word.dstr_type?
      string_literal = to_string_literal(word.source)

  build_bracketed_array_with_appropriate_whitespace(elements: words, node: node)

#complex_content?(strings, complex_regex: word_regex) ⇒ Boolean (private)

[ GitHub ]

# File 'lib/rubocop/cop/style/word_array.rb', line 118

def complex_content?(strings, complex_regex: word_regex)
  strings.any? do |s|
    next unless s.str_content

    string = s.str_content.dup.force_encoding(::Encoding::UTF_8)
    !string.valid_encoding? ||
      (complex_regex && !complex_regex.match?(string)) ||
      string.include?(' ')

#invalid_percent_array_contents?(node) ⇒ Boolean (private)

[ GitHub ]

# File 'lib/rubocop/cop/style/word_array.rb', line 129

def invalid_percent_array_contents?(node)
  # Disallow %w() arrays that contain invalid encoding or spaces
  complex_content?(node.values, complex_regex: false)

#matrix_of_complex_content?(array) ⇒ Boolean (private)

[ GitHub ]

# File 'lib/rubocop/cop/style/word_array.rb', line 113

def matrix_of_complex_content?(array)
  array.values.all?(&:array_type?) &&
    array.values.any? { |subarray| complex_content?(subarray.values) }


[ GitHub ]

# File 'lib/rubocop/cop/style/word_array.rb', line 94

def on_array(node)
  if bracketed_array_of?(:str, node)
    return if complex_content?(node.values)
    return if within_matrix_of_complex_content?(node)

    check_bracketed_array(node, 'w')
  elsif node.percent_literal?(:string)


[ GitHub ]

# File 'lib/rubocop/cop/style/word_array.rb', line 85

def on_new_investigation

  # Prevent O(n2) checks (checking the entire matrix once for each child array) by caching
  @matrix_of_complex_content_cache = Hash.new do |cache, node|
    cache[node] = matrix_of_complex_content?(node)

#within_matrix_of_complex_content?(node) ⇒ Boolean (private)

[ GitHub ]

# File 'lib/rubocop/cop/style/word_array.rb', line 107

def within_matrix_of_complex_content?(node)
  return false unless (parent = node.parent)

  parent.array_type? && @matrix_of_complex_content_cache[parent]

#word_regex (private)

[ GitHub ]

# File 'lib/rubocop/cop/style/word_array.rb', line 134

def word_regex