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

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, #always_autocorrect?, autocorrect_incompatible_with, badge, #begin_investigation, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #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, #parser_engine, #ready, #relevant_file?, requires_gem, 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