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

Inherits:

Base

• Object
• Base
• RuboCop::Cop::Style::FrozenStringLiteralComment

Extended by:

AutoCorrector, TargetRubyVersion

Includes:

ConfigurableEnforcedStyle, FrozenStringLiteral, RangeHelp

Defined in:

lib/rubocop/cop/style/frozen_string_literal_comment.rb

Overview

Helps you transition from mutable string literals to frozen string literals. It will add the # frozen_string_literal: true magic comment to the top of files to enable frozen string literals. Frozen string literals may be default in future Ruby. The comment will be added below a shebang and encoding comment. The frozen string literal comment is only valid in Ruby 2.3+.

Note that the cop will accept files where the comment exists but is set to false instead of true.

To require a blank line after this comment, please see Layout/EmptyLineAfterMagicComment cop.

Examples:

EnforcedStyle: always (default)

# 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

# good
# frozen_string_literal: false

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

EnforcedStyle: always_true

# The `always_true` style enforces that the frozen string literal
# comment is set to `true`. This is a stricter option than `always`
# and forces projects to use frozen string literals.
# bad
# frozen_string_literal: false

module Baz
  # ...
end

# bad
module Baz
  # ...
end

# good
# frozen_string_literal: true

module Bar
  # ...
end

Cop Safety Information:

• This cop’s autocorrection is unsafe since any strings mutations will change from being accepted to raising FrozenError, as all strings will become frozen by default, and will need to be manually refactored.

Constant Summary

MSG_MISSING_TRUE =

'Missing magic comment `# frozen_string_literal: true`.'

MSG_MISSING =

'Missing frozen string literal comment.'

MSG_UNNECESSARY =

'Unnecessary frozen string literal comment.'

MSG_DISABLED =

'Frozen string literal comment must be set to `true`.'

SHEBANG =

'#!'

Constants included from FrozenStringLiteral

FrozenStringLiteral::FROZEN_STRING_LITERAL, FrozenStringLiteral::FROZEN_STRING_LITERAL_ENABLED

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary

• #on_new_investigation ⇒ Object

Methods included from AutoCorrector

support_autocorrect?

Methods included from TargetRubyVersion

minimum_target_ruby_version, required_minimum_ruby_version, support_target_ruby_version?

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_configured?, #style_detected, #style_parameter_name, #supported_styles, #unexpected_style_detected

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #begin_investigation, #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, #inspect, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #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

#on_new_investigation ⇒ Object

# File 'lib/rubocop/cop/style/frozen_string_literal_comment.rb', line 99

def on_new_investigation
  return if processed_source.tokens.empty?

  case style
  when :never
    ensure_no_comment(processed_source)
  when :always_true
    ensure_enabled_comment(processed_source)
  else
    ensure_comment(processed_source)
  end
end