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Class: RuboCop::Cop::Style::RedundantRegexpEscape

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/redundant_regexp_escape.rb

Overview

Checks for redundant escapes inside Regexp literals.

Examples:

# bad
%r{foo\/bar}

# good
%r{foo/bar}

# good
/foo\/bar/

# good
%r/foo\/bar/

# good
%r!foo\!bar!

# bad
/a\-b/

# good
/a-b/

# bad
/[\+\-]\d/

# good
/[+\-]\d/

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::RangeHelp - Included

BYTE_ORDER_MARK, NOT_GIVEN

Class Attribute Summary

::RuboCop::Cop::AutoCorrector - Extended

::RuboCop::Cop::Base - Inherited

.gem_requirements, .lint?,
.support_autocorrect?

Returns if class supports autocorrect.

.support_multiple_source?

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

.autocorrect_incompatible_with

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

.badge

Naming.

.callbacks_needed, .cop_name, .department,
.documentation_url

Returns an url to view this cops documentation online.

.exclude_from_registry

Call for abstract Cop classes.

.inherited,
.joining_forces

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

.match?

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

.new,
.requires_gem

Register a version requirement for the given gem name.

.restrict_on_send

::RuboCop::ExcludeLimit - Extended

exclude_limit

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

transform

Instance Attribute Summary

Instance Method Summary

::RuboCop::Cop::RangeHelp - Included

#add_range, #column_offset_between,
#contents_range

A range containing only the contents of a literal with delimiters (e.g.

#directions,
#effective_column

Returns the column attribute of the range, except if the range is on the first line and there’s a byte order mark at the beginning of that line, in which case 1 is subtracted from the column value.

#final_pos, #move_pos, #move_pos_str, #range_between, #range_by_whole_lines, #range_with_comments, #range_with_comments_and_lines, #range_with_surrounding_comma, #range_with_surrounding_space, #source_range

::RuboCop::Cop::Base - Inherited

#add_global_offense

Adds an offense that has no particular location.

#add_offense

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.

#begin_investigation

Called before any investigation.

#callbacks_needed,
#cop_config

Configuration Helpers.

#cop_name, #excluded_file?,
#external_dependency_checksum

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

#inspect
#message

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.

#name

Alias for Base#cop_name.

#offenses,
#on_investigation_end

Called after all on_…​

#on_new_investigation

Called before all on_…​

#on_other_file

Called instead of all on_…​

#parse

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

#parser_engine,
#ready

Called between investigations.

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

Reserved for Cop::Cop.

#complete_investigation

Called to complete an investigation.

#correct, #current_corrector,
#current_offense_locations

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,
#reset_investigation

Actually private methods.

#use_corrector

::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

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

Instance Method Details

#allowed_escape?(node, char, index, within_character_class) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/redundant_regexp_escape.rb', line 60

def allowed_escape?(node, char, index, within_character_class)
  # Strictly speaking a few single-letter metachars are currently
  # unnecessary to "escape", e.g. i, E, F, but enumerating them is
  # rather difficult, and their behavior could change over time with
  # different versions of Ruby so that e.g. /\i/ != /i/
  return true if /[[:alnum:]]/.match?(char)
  return true if ALLOWED_ALWAYS_ESCAPES.include?(char) || delimiter?(node, char)

  if within_character_class
    ALLOWED_WITHIN_CHAR_CLASS_METACHAR_ESCAPES.include?(char) &&
      !char_class_begins_or_ends_with_escaped_hyphen?(node, index)
  else
    ALLOWED_OUTSIDE_CHAR_CLASS_METACHAR_ESCAPES.include?(char)
  end
end

#char_class_begins_or_ends_with_escaped_hyphen?(node, index) ⇒ Boolean (private)

[ GitHub ]

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

def char_class_begins_or_ends_with_escaped_hyphen?(node, index)
  # The hyphen character is allowed to be escaped within a character class
  # but it's not necessary to escape hyphen if it's the first or last character
  # within the character class. This method checks if that's the case.
  # e.g. "[0-9\\-]" or "[\\-0-9]" would return true
  content = contents_range(node).source

  if content[index + 2] == ']'
    true
  elsif content[index - 1] == '['
    index < 2 || content[index - 2] != '\\'
  else
    false
  end
end

#delimiter?(node, char) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/redundant_regexp_escape.rb', line 92

def delimiter?(node, char)
  delimiters = [node.loc.begin.source[-1], node.loc.end.source[0]]

  delimiters.include?(char)
end

#each_escape(node) (private)

Please remove this else branch when support for regexp_parser 1.8 will be dropped. It’s for compatibility with regexp_parser 1.8 and will never be maintained.

[ GitHub ]

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

def each_escape(node)
  node.parsed_tree&.traverse&.reduce(0) do |char_class_depth, (event, expr)|
    yield(expr.text[1], expr.ts, !char_class_depth.zero?) if expr.type == :escape

    if expr.type == :set
      char_class_depth + (event == :enter ? 1 : -1)
    else
      char_class_depth
    end
  end
end

#escape_range_at_index(node, index) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/redundant_regexp_escape.rb', line 126

def escape_range_at_index(node, index)
  regexp_begin = node.loc.begin.end_pos

  start = regexp_begin + index

  range_between(start, start + 2)
end

#on_regexp(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/redundant_regexp_escape.rb', line 45

def on_regexp(node)
  each_escape(node) do |char, index, within_character_class|
    next if char.valid_encoding? && allowed_escape?(node, char, index,
                                                    within_character_class)

    location = escape_range_at_index(node, index)

    add_offense(location, message: MSG_REDUNDANT_ESCAPE) do |corrector|
      corrector.remove_leading(escape_range_at_index(node, index), 1)
    end
  end
end