class SCSSLint::Linter::UnnecessaryParentReference

Checks for unnecessary uses of the parent reference (&) in nested selectors.

Constants

MESSAGE

Public Instance Methods

visit_comma_sequence(comma_sequence) click to toggle source
# File lib/scss_lint/linter/unnecessary_parent_reference.rb, line 10
def visit_comma_sequence(comma_sequence)
  @multiple_sequences = comma_sequence.members.size > 1
end
visit_sequence(sequence) click to toggle source
# File lib/scss_lint/linter/unnecessary_parent_reference.rb, line 14
def visit_sequence(sequence)
  return unless sequence_starts_with_parent?(sequence.members.first)

  # Allow concatentation, e.g.
  # element {
  #   &.foo {}
  # }
  return if sequence.members.first.members.size > 1

  # Allow sequences that contain multiple parent references, e.g.
  # element {
  #   & + & { ... }
  # }
  return if sequence.members[1..-1].any? { |ss| sequence_contains_parent_reference?(ss) }

  # Special case: allow an isolated parent to appear if it is part of a
  # comma sequence of more than one sequence, as this could be used to DRY
  # up code.
  return if @multiple_sequences && isolated_parent?(sequence)

  add_lint(sequence.members.first.line, MESSAGE)
end

Private Instance Methods

isolated_parent?(sequence) click to toggle source
# File lib/scss_lint/linter/unnecessary_parent_reference.rb, line 39
def isolated_parent?(sequence)
  sequence.members.size == 1 &&
    sequence_starts_with_parent?(sequence.members.first)
end
sequence_contains_parent_reference?(simple_sequence) click to toggle source
# File lib/scss_lint/linter/unnecessary_parent_reference.rb, line 51
def sequence_contains_parent_reference?(simple_sequence)
  return unless simple_sequence.is_a?(Sass::Selector::SimpleSequence)
  simple_sequence.members.any? { |s| s.is_a?(Sass::Selector::Parent) }
end
sequence_starts_with_parent?(simple_sequence) click to toggle source
# File lib/scss_lint/linter/unnecessary_parent_reference.rb, line 44
def sequence_starts_with_parent?(simple_sequence)
  return unless simple_sequence.is_a?(Sass::Selector::SimpleSequence)
  first = simple_sequence.members.first
  first.is_a?(Sass::Selector::Parent) &&
    first.suffix.nil? # Ignore concatenated selectors, like `&-something`
end