class RuboCop::Cop::Style::RedundantRegexpEscape
Checks for redundant escapes inside ‘Regexp` literals.
@example
# 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/
Constants
- ALLOWED_ALWAYS_ESCAPES
- ALLOWED_OUTSIDE_CHAR_CLASS_METACHAR_ESCAPES
- ALLOWED_WITHIN_CHAR_CLASS_METACHAR_ESCAPES
- MSG_REDUNDANT_ESCAPE
Public Instance Methods
Source
# 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
Private Instance Methods
Source
# 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
Source
# 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
Source
# 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
Source
# File lib/rubocop/cop/style/redundant_regexp_escape.rb, line 98 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
Source
# File lib/rubocop/cop/style/redundant_regexp_escape.rb, line 110 def escape_range_at_index(node, index) regexp_begin = node.loc.begin.end_pos start = regexp_begin + index range_between(start, start + 2) end