Class: RuboCop::Cop::Style::FrozenStringLiteralComment

Inherits:
Cop
  • Object
show all
Includes:
ConfigurableEnforcedStyle, FrozenStringLiteral
Defined in:
lib/rubocop/cop/style/frozen_string_literal_comment.rb

Overview

This cop is designed to help upgrade to Ruby 3.0. It will add the comment ‘# frozen_string_literal: true` to the top of files to enable frozen string literals. Frozen string literals may be default in Ruby 3.0. The comment will be added below a shebang and encoding comment. The frozen string literal comment is only valid in Ruby 2.3+.

Examples:

EnforcedStyle: when_needed (default)

# The `when_needed` style will add the frozen string literal comment
# to files only when the `TargetRubyVersion` is set to 2.3+.
# bad
module Foo
  # ...
end

# good
# frozen_string_literal: true

module Foo
  # ...
end

EnforcedStyle: always

# The `always` style will always add the frozen string literal comment
# to a file, regardless of the Ruby version or if `freeze` or `<<` are
# called on a string literal.
# bad
module Bar
  # ...
end

# good
# frozen_string_literal: true

module Bar
  # ...
end

EnforcedStyle: never

# The `never` will enforce that the frozen string literal comment does
# not exist in a file.
# bad
# frozen_string_literal: true

module Baz
  # ...
end

# good
module Baz
  # ...
end

Constant Summary collapse

MSG = 
'Missing magic comment `# frozen_string_literal: true`.'.freeze
MSG_UNNECESSARY = 
'Unnecessary frozen string literal comment.'.freeze
SHEBANG = 
'#!'.freeze

Constants included from FrozenStringLiteral

FrozenStringLiteral::FROZEN_STRING_LITERAL, FrozenStringLiteral::FROZEN_STRING_LITERAL_ENABLED, FrozenStringLiteral::FROZEN_STRING_LITERAL_TYPES

Constants included from Util

Util::ASGN_NODES, Util::BYTE_ORDER_MARK, Util::CONDITIONAL_NODES, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, Util::LOGICAL_OPERATOR_NODES, Util::MODIFIER_NODES, Util::OPERATOR_METHODS, Util::SHORTHAND_ASGN_NODES

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods included from FrozenStringLiteral

frozen_string_literal_comment_exists?

Methods included from ConfigurableEnforcedStyle

#alternative_style, #alternative_styles, #ambiguous_style_detected, #correct_style_detected, #detected_style, #detected_style=, #no_acceptable_style!, #no_acceptable_style?, #opposite_style_detected, #style, #style_detected, #style_parameter_name, #supported_styles, #unexpected_style_detected

Methods inherited from Cop

#add_offense, all, autocorrect_incompatible_with, badge, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, #correct, department, #duplicate_location?, #excluded_file?, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, non_rails, #parse, qualified_cop_name, #relevant_file?, #target_rails_version, #target_ruby_version

Methods included from AST::Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search, #node_search_all, #node_search_body, #node_search_first

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, comment_line?, double_quotes_required?, effective_column, ends_its_line?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, needs_escaping?, on_node, operator?, parentheses?, parenthesized_call?, precede?, range_between, range_by_whole_lines, range_with_surrounding_comma, range_with_surrounding_space, same_line?, source_range, strip_quotes, stripped_source_upto, symbol_without_quote?, to_string_literal, to_supported_styles, to_symbol_literal, within_node?

Methods included from PathUtil

absolute?, find_file_upwards, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

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

Instance Method Details

#autocorrect(node) ⇒ Object

rubocop:disable Metrics/MethodLength



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# File 'lib/rubocop/cop/style/frozen_string_literal_comment.rb', line 76

def autocorrect(node) # rubocop:disable Metrics/MethodLength
  lambda do |corrector|
    if style == :never
      corrector.remove(range_with_surrounding_space(range: node.pos,
                                                    side: :right))
    else
      last_special_comment = last_special_comment(processed_source)
      if last_special_comment.nil?
        corrector.insert_before(processed_source.tokens[0].pos,
                                "#{FROZEN_STRING_LITERAL_ENABLED}\n")
      else
        corrector.insert_after(last_special_comment.pos,
                               "\n#{FROZEN_STRING_LITERAL_ENABLED}")
      end
    end
  end
end

#investigate(processed_source) ⇒ Object 



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# File 'lib/rubocop/cop/style/frozen_string_literal_comment.rb', line 65

def investigate(processed_source)
  return if style == :when_needed && target_ruby_version < 2.3
  return if processed_source.tokens.empty?

  if frozen_string_literal_comment_exists?
    check_for_no_comment(processed_source)
  else
    check_for_comment(processed_source)
  end
end