Class: RuboCop::Cop::Lint::SymbolConversion

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/lint/symbol_conversion.rb


Checks for uses of literal strings converted to a symbol where a literal symbol could be used instead.

There are two possible styles for this cop. strict (default) will register an offense for any incorrect usage. consistent additionally requires hashes to use the same style for every symbol key (ie. if any symbol key needs to be quoted it requires all keys to be quoted).


# bad

# good

EnforcedStyle: strict (default)

# bad
  'a': 1,
  "b": 2,
  'c-d': 3

# good (don't quote keys that don't require quoting)
  a: 1,
  b: 2,
  'c-d': 3

EnforcedStyle: consistent

# bad
  a: 1,
  'b-c': 2

# good (quote all keys if any need quoting)
  'a': 1,
  'b-c': 2

# good (no quoting required)
  a: 1,
  b: 2

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::SymbolHelp - Included

::RuboCop::Cop::ConfigurableEnforcedStyle - 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

Instance Method Details

#correct_hash_key(node) (private)

[ GitHub ]

# File 'lib/rubocop/cop/lint/symbol_conversion.rb', line 147

def correct_hash_key(node)
  # Although some operators can be converted to symbols normally
  # (ie. `:==`), these are not accepted as hash keys and will
  # raise a syntax error (eg. `{ ==: ... }`). Therefore, if the
  # symbol does not start with an alphanumeric or underscore, it
  # will be ignored.
  return unless node.value.to_s.match?(/\A[a-z0-9_]/i)

  correction = node.value.inspect
  correction = correction.delete_prefix(':') if node.parent.colon?
  return if properly_quoted?(node.source, correction)

    correction: correction,
    message: format(MSG, correction: node.parent.colon? ? "#{correction}:" : correction)

#correct_inconsistent_hash_keys(keys) (private)

[ GitHub ]

# File 'lib/rubocop/cop/lint/symbol_conversion.rb', line 166

def correct_inconsistent_hash_keys(keys)
  keys.each do |key|

    next if requires_quotes?(key)
    next if properly_quoted?(key.source, %("#{key.value}"))

    correction = %("#{key.value}")
      correction: correction,
      message: format(MSG_CONSISTENCY, correction: "#{correction}:")

#in_alias?(node) ⇒ Boolean (private)

[ GitHub ]

# File 'lib/rubocop/cop/lint/symbol_conversion.rb', line 139

def in_alias?(node)

#in_percent_literal_array?(node) ⇒ Boolean (private)

[ GitHub ]

# File 'lib/rubocop/cop/lint/symbol_conversion.rb', line 143

def in_percent_literal_array?(node)
  node.parent&.array_type? && node.parent&.percent_literal?


[ GitHub ]

# File 'lib/rubocop/cop/lint/symbol_conversion.rb', line 105

def on_hash(node)
  # For `EnforcedStyle: strict`, hash keys are evaluated in `on_sym`
  return unless style == :consistent

  keys = node.keys.select(&:sym_type?)

  if keys.any? { |key| requires_quotes?(key) }
    # If there are no symbol keys requiring quoting,
    # treat the hash like `EnforcedStyle: strict`.
    keys.each { |key| correct_hash_key(key) }


[ GitHub ]

# File 'lib/rubocop/cop/lint/symbol_conversion.rb', line 78

def on_send(node)
  return unless node.receiver

  if node.receiver.str_type? || node.receiver.sym_type?
    register_offense(node, correction: node.receiver.value.to_sym.inspect)
  elsif node.receiver.dstr_type?
    register_offense(node, correction: ":\"#{node.receiver.value.to_sym}\"")


[ GitHub ]

# File 'lib/rubocop/cop/lint/symbol_conversion.rb', line 88

def on_sym(node)
  return if ignored_node?(node) || properly_quoted?(node.source, node.value.inspect)

  # `alias` arguments are symbols but since a symbol that requires
  # being quoted is not a valid method identifier, it can be ignored
  return if in_alias?(node)

  # The `%I[]` and `%i[]` macros are parsed as normal arrays of symbols
  # so they need to be ignored.
  return if in_percent_literal_array?(node)

  # Symbol hash keys have a different format and need to be handled separately
  return correct_hash_key(node) if hash_key?(node)

  register_offense(node, correction: node.value.inspect)

#properly_quoted?(source, value) ⇒ Boolean (private)

[ GitHub ]

# File 'lib/rubocop/cop/lint/symbol_conversion.rb', line 126

def properly_quoted?(source, value)
  return true if style == :strict && (!source.match?(/['"]/) || value.end_with?('='))

  source == value ||
    # `Symbol#inspect` uses double quotes, but allow single-quoted
    # symbols to work as well.
    source.gsub('"', '\"').tr("'", '"') == value

#register_offense(node, correction:, message: format(MSG, correction: correction)) (private)

[ GitHub ]

# File 'lib/rubocop/cop/lint/symbol_conversion.rb', line 122

def register_offense(node, correction:, message: format(MSG, correction: correction))
  add_offense(node, message: message) { |corrector| corrector.replace(node, correction) }

#requires_quotes?(sym_node) ⇒ Boolean (private)

[ GitHub ]

# File 'lib/rubocop/cop/lint/symbol_conversion.rb', line 135

def requires_quotes?(sym_node)