lib/rubocop/cop/util.rb


# frozen_string_literal: true

module RuboCop
  module Cop
    # This module contains a collection of useful utility methods.
    module Util
      include PathUtil

      # Match literal regex characters, not including anchors, character
      # classes, alternatives, groups, repetitions, references, etc
      LITERAL_REGEX =
        %r{[\w\s\-,"'!#%&<>=;:`~/]|\\[^AbBdDgGhHkpPRwWXsSzZ0-9]}.freeze

      module_function

      # This is a bad API
      def comment_line?(line_source)
        /^\s*#/.match?(line_source)
      end

      # @deprecated Use `ProcessedSource#line_with_comment?`, `contains_comment?` or similar
      def comment_lines?(node)
        processed_source[line_range(node)].any? { |line| comment_line?(line) }
      end

      def line_range(node)
        node.first_line..node.last_line
      end

      def parentheses?(node)
        node.loc.respond_to?(:end) && node.loc.end &&
          node.loc.end.is?(')')
      end

      def add_parentheses(node, corrector)
        if !node.respond_to?(:arguments)
          corrector.wrap(node, '(', ')')
        elsif node.arguments.empty?
          corrector.insert_after(node, '()')
        else
          args_begin = args_begin(node)

          corrector.remove(args_begin)
          corrector.insert_before(args_begin, '(')
          corrector.insert_after(args_end(node), ')')
        end
      end

      def args_begin(node)
        loc = node.loc
        selector =
          node.super_type? || node.yield_type? ? loc.keyword : loc.selector
        selector.end.resize(1)
      end

      def args_end(node)
        node.loc.expression.end
      end

      def on_node(syms, sexp, excludes = [], &block)
        return to_enum(:on_node, syms, sexp, excludes) unless block

        yield sexp if Array(syms).include?(sexp.type)
        return if Array(excludes).include?(sexp.type)

        sexp.each_child_node { |elem| on_node(syms, elem, excludes, &block) }
      end

      def begins_its_line?(range)
        range.source_line.index(/\S/) == range.column
      end

      # Returns, for example, a bare `if` node if the given node is an `if`
      # with calls chained to the end of it.
      def first_part_of_call_chain(node)
        while node
          case node.type
          when :send
            node = node.receiver
          when :block
            node = node.send_node
          else
            break
          end
        end
        node
      end

      # If converting a string to Ruby string literal source code, must
      # double quotes be used?
      def double_quotes_required?(string)
        # Double quotes are required for strings which either:
        # - Contain single quotes
        # - Contain non-printable characters, which must use an escape

        # Regex matches IF there is a ' or there is a \\ in the string that is
        # not preceded/followed by another \\ (e.g. "\\x34") but not "\\\\".
        /'|(?<! \\) \\{2}* \\ (?![\\"])/x.match?(string)
      end

      def needs_escaping?(string)
        double_quotes_required?(escape_string(string))
      end

      def escape_string(string)
        string.inspect[1..-2].tap { |s| s.gsub!(/\\"/, '"') }
      end

      def to_string_literal(string)
        if needs_escaping?(string) && compatible_external_encoding_for?(string)
          string.inspect
        else
          "'#{string.gsub('\\') { '\\\\' }}'"
        end
      end

      def trim_string_interporation_escape_character(str)
        str.gsub(/\\\#\{(.*?)\}/) { "\#{#{Regexp.last_match(1)}}" }
      end

      def interpret_string_escapes(string)
        StringInterpreter.interpret(string)
      end

      def same_line?(node1, node2)
        node1.respond_to?(:loc) &&
          node2.respond_to?(:loc) &&
          node1.loc.line == node2.loc.line
      end

      def indent(node)
        ' ' * node.loc.column
      end

      def to_supported_styles(enforced_style)
        enforced_style
          .sub(/^Enforced/, 'Supported')
          .sub('Style', 'Styles')
      end

      private

      def compatible_external_encoding_for?(src)
        src = src.dup if RUBY_ENGINE == 'jruby'
        src.force_encoding(Encoding.default_external).valid_encoding?
      end
    end
  end
end