class RuboCop::Cop::Lint::UnneededDisable

This cop detects instances of rubocop:disable comments that can be removed without causing any offenses to be reported. It's implemented as a cop in that it inherits from the Cop base class and calls add_offense. The unusual part of its implementation is that it doesn't have any on_* methods or an investigate method. This means that it doesn't take part in the investigation phase when the other cops do their work. Instead, it waits until it's called in a later stage of the execution. The reason it can't be implemented as a normal cop is that it depends on the results of all other cops to do its work.

Constants

COP_NAME

Public Instance Methods

autocorrect(args) click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 31
def autocorrect(args)
  lambda do |corrector|
    ranges, range = *args # ranges are sorted by position

    if range.source.start_with?('#')
      # eat the entire comment and following newline
      corrector.remove(range_with_surrounding_space(range, :right))
    else
      # is there any cop between this one and the end of the line, which
      # is NOT being removed?

      if ends_its_line?(ranges.last) && trailing_range?(ranges, range)
        # eat the comma on the left
        range = range_with_surrounding_space(range, :left)
        range = range_with_surrounding_comma(range, :left)
      end

      range = range_with_surrounding_comma(range, :right)
      # eat following spaces up to EOL, but not the newline itself
      range = range_with_surrounding_space(range, :right, false)

      corrector.remove(range)
    end
  end
end
check(offenses, cop_disabled_line_ranges, comments) click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 20
def check(offenses, cop_disabled_line_ranges, comments)
  unneeded_cops = Hash.new { |h, k| h[k] = Set.new }

  each_unneeded_disable(cop_disabled_line_ranges,
                        offenses, comments) do |comment, unneeded_cop|
    unneeded_cops[comment].add(unneeded_cop)
  end

  add_offenses(unneeded_cops)
end

Private Instance Methods

add_offenses(unneeded_cops) click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 117
def add_offenses(unneeded_cops)
  unneeded_cops.each do |comment, cops|
    # Is the entire rubocop:disable line useless, or should just
    # some of the mentioned cops be removed?
    if all_disabled?(comment) ||
       directive_count(comment) == cops.size
      location = comment.loc.expression
      cop_list = cops.sort.map { |c| describe(c) }
      add_offense([[location], location], location,
                  "Unnecessary disabling of #{cop_list.join(', ')}.")
    else
      cop_ranges = cops.map { |c| [c, cop_range(comment, c)] }
      cop_ranges.sort_by! { |_, r| r.begin_pos }
      ranges = cop_ranges.map { |_, r| r }

      cop_ranges.each do |cop, range|
        add_offense([ranges, range], range,
                    "Unnecessary disabling of #{describe(cop)}.")
      end
    end
  end
end
all_cop_names() click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 181
def all_cop_names
  @all_cop_names ||= Cop.all.map(&:cop_name)
end
all_disabled?(comment) click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 101
def all_disabled?(comment)
  comment.text =~ /rubocop:disable\s+all\b/
end
collect_variable_like_names(scope) click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 177
def collect_variable_like_names(scope)
  all_cop_names.each { |name| scope << name }
end
cop_range(comment, cop) click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 140
def cop_range(comment, cop)
  matching_range(comment.loc.expression, cop) ||
    matching_range(comment.loc.expression, cop.split('/').last) ||
    raise("Couldn't find #{cop} in comment: #{comment.text}")
end
describe(cop) click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 162
def describe(cop)
  if cop == 'all'
    'all cops'
  elsif all_cop_names.include?(cop)
    "`#{cop}`"
  else
    similar = find_similar_name(cop, [])
    if similar
      "`#{cop}` (did you mean `#{similar}`?)"
    else
      "`#{cop}` (unknown cop)"
    end
  end
end
directive_count(comment) click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 111
def directive_count(comment)
  match = comment.text.match(CommentConfig::COMMENT_DIRECTIVE_REGEXP)
  _, cops_string = match.captures
  cops_string.split(/,\s*/).size
end
each_already_disabled(line_ranges, comments) { |find { |c| loc.line == begin }| ... } click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 80
def each_already_disabled(line_ranges, comments)
  line_ranges.each_cons(2) do |previous_range, range|
    next if previous_range.end != range.begin

    # If a cop is disabled in a range that begins on the same line as
    # the end of the previous range, it means that the cop was
    # already disabled by an earlier comment. So it's unneeded
    # whether there are offenses or not.
    yield comments.find { |c| c.loc.line == range.begin }
  end
end
each_unneeded_disable(cop_disabled_line_ranges, offenses, comments) { |comment, cop| ... } click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 59
def each_unneeded_disable(cop_disabled_line_ranges, offenses, comments)
  disabled_ranges = cop_disabled_line_ranges[COP_NAME] || [0..0]

  cop_disabled_line_ranges.each do |cop, line_ranges|
    each_already_disabled(line_ranges, comments) do |comment|
      yield comment, cop
    end

    line_ranges.each do |line_range|
      comment = comments.find { |c| c.loc.line == line_range.begin }

      unless all_disabled?(comment)
        next if ignore_offense?(disabled_ranges, line_range)
      end

      unneeded_cop = find_unneeded(comment, offenses, cop, line_range)
      yield comment, unneeded_cop if unneeded_cop
    end
  end
end
find_unneeded(comment, offenses, cop, line_range) click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 92
def find_unneeded(comment, offenses, cop, line_range)
  if all_disabled?(comment)
    'all' if offenses.none? { |o| line_range.cover?(o.line) }
  else
    cop_offenses = offenses.select { |o| o.cop_name == cop }
    cop if cop_offenses.none? { |o| line_range.cover?(o.line) }
  end
end
ignore_offense?(disabled_ranges, line_range) click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 105
def ignore_offense?(disabled_ranges, line_range)
  disabled_ranges.any? do |range|
    range.cover?(line_range.min) && range.cover?(line_range.max)
  end
end
matching_range(haystack, needle) click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 146
def matching_range(haystack, needle)
  offset = (haystack.source =~ Regexp.new(Regexp.escape(needle)))
  return unless offset
  offset += haystack.begin_pos
  Parser::Source::Range.new(haystack.source_buffer, offset,
                            offset + needle.size)
end
trailing_range?(ranges, range) click to toggle source
# File lib/rubocop/cop/lint/unneeded_disable.rb, line 154
def trailing_range?(ranges, range)
  ranges
    .drop_while { |r| !r.equal?(range) }
    .each_cons(2)
    .map { |r1, r2| r1.end.join(r2.begin).source }
    .all? { |intervening| intervening =~ /\A\s*,\s*\Z/ }
end