Class: RuboCop::Cop::Lint::LiteralInInterpolation

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 79

def autocorrected_value(node)
  case node.type
  when :int
    node.children.last.to_i.to_s
  when :float
    node.children.last.to_f.to_s
  when :str
    autocorrected_value_for_string(node)
  when :sym
    autocorrected_value_for_symbol(node)
  when :array
    autocorrected_value_for_array(node)
  when :hash
    autocorrected_value_for_hash(node)
  when :nil
    ''
  else
    node.source.gsub('"', '\"')
  end
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 153

def autocorrected_value_for_array(node)
  return node.source.gsub('"', '\"') unless node.percent_literal?

  contents_range(node).source.split.to_s.gsub('"', '\"')
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 159

def autocorrected_value_for_hash(node)
  hash_string = node.children.map do |child|
    key = autocorrected_value_in_hash(child.key)
    value = autocorrected_value_in_hash(child.value)
    "#{key}=>#{value}"
  end.join(', ')

  "{#{hash_string}}"
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 132

def autocorrected_value_for_string(node)
  return node.source.delete_prefix('"').delete_suffix('"') unless node.value.valid_encoding?

  escape_string_content(node.children.last)
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 142

def autocorrected_value_for_symbol(node)
  end_pos =
    node.loc.end ? node.loc.end.begin_pos : node.source_range.end_pos

  range_between(node.loc.begin.end_pos, end_pos).source.gsub('"', '\"')
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 170

def autocorrected_value_in_hash(node)
  case node.type
  when :int
    node.children.last.to_i.to_s
  when :float
    node.children.last.to_f.to_s
  when :str
    escape_string_content(node.value.inspect)
  when :sym
    autocorrected_value_in_hash_for_symbol(node)
  when :array
    autocorrected_value_for_array(node)
  when :hash
    autocorrected_value_for_hash(node)
  else
    node.source.gsub('"', '\"')
  end
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 149

def autocorrected_value_in_hash_for_symbol(node)
  escape_string_content(node.value.inspect)
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 62

def correctable_value(begin_node, final_node)
  value = autocorrected_value(final_node)
  value = handle_special_regexp_chars(begin_node, value)
  return if starts_interpolation_after_hash_sign?(begin_node, value)

  value = escape_trailing_hash_sign(begin_node, value)

  # %W and %I split the content into words before expansion
  # treating each interpolation as a word component, so
  # interpolation should not be removed if the expanded value
  # contains a space character.
  return if in_array_percent_literal?(begin_node) && /\s|\A\z/.match?(value)

  value
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 201

def ends_heredoc_line?(node)
  grandparent = node.parent.parent
  return false unless grandparent&.dstr_type? && grandparent.heredoc?

  line = processed_source.lines[node.last_line - 1]

  line.size == node.parent.source_range.last_column
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 138

def escape_string_content(string)
  string.gsub(/[\\"]|#(?=[@{$])/, '\\\\\&')
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 218

def escape_trailing_hash_sign(begin_node, value)
  following = processed_source.buffer.source[begin_node.source_range.end_pos]
  return value unless %w[{ @ $].include?(following) && unescaped_hash_sign?(value)

  "#{value.delete_suffix('#')}\\#"
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 232

def follows_literal_interpolation?(begin_node)
  previous = begin_node.left_sibling
  return false unless previous&.begin_type? && offending?(previous.children.last)

  value = correctable_value(previous, previous.children.last)
  value && (value.empty? || value.end_with?('#'))
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 100

def handle_special_regexp_chars(begin_node, value)
  parent_node = begin_node.parent

  return value unless parent_node.regexp_type? && parent_node.slash_literal? && value['/']

  # When a literal string containing a forward slash preceded by backslashes
  # is interpolated inside a regexp, the number of resultant backslashes in the
  # compiled Regexp is `(2(n+1) / 4)+1`, where `n` is the number of backslashes
  # inside the interpolation.
  # ie. 0-2 backslashes is compiled to 1, 3-6 is compiled to 3, etc.
  # This maintains that same behavior in order to ensure the Regexp behavior
  # does not change upon removing the interpolation.
  value.gsub(%r{(\\*)/}) do
    backslashes = Regexp.last_match[1]
    backslash_count = backslashes.length
    needed_backslashes = (2 * ((backslash_count + 1) / 4)) + 1

    "#{'\\' * needed_backslashes}/"
  end
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 210

def in_array_percent_literal?(node)
  parent = node.parent
  return false unless parent.type?(:dstr, :dsym)

  grandparent = parent.parent
  grandparent&.array_type? && grandparent.percent_literal?
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 42

def offending?(node)
  node &&
    !special_keyword?(node) &&
    prints_as_self?(node) &&
    # Special case for `Layout/TrailingWhitespace`
    !(space_literal?(node) && ends_heredoc_line?(node)) &&
    # Handled by `Lint/ArrayLiteralInRegexp`
    !array_in_regexp?(node)
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 27

def on_interpolation(begin_node)
  final_node = begin_node.children.last
  return unless offending?(final_node)
  return unless (expanded_value = correctable_value(begin_node, final_node))

  add_offense(final_node) do |corrector|
    next if final_node.dstr_type? # nested, fixed in next iteration
    next if follows_literal_interpolation?(begin_node)

    corrector.replace(final_node.parent, replacement(final_node, expanded_value))
  end
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 190

def prints_as_self?(node)
  node.basic_literal? ||
    (COMPOSITE.include?(node.type) && node.children.all? { |child| prints_as_self?(child) })
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 240

def replacement(node, expanded_value)
  return expanded_value unless node.str_type? && !node.value.valid_encoding?

  node.source.delete_prefix('"').delete_suffix('"')
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 195

def space_literal?(node)
  # `String#blank?` misses Unicode spaces such as U+3000 that
  # `Layout/TrailingWhitespace` treats as trailing whitespace.
  node.str_type? && node.value.valid_encoding? && node.value.match?(/\A[[:space:]]*\z/)
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 52

def special_keyword?(node)
  # handle strings like __FILE__
  (node.str_type? && !node.loc?(:begin)) || node.source_range.is?('__LINE__')
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 121

def starts_interpolation_after_hash_sign?(begin_node, value)
  source = processed_source.buffer.source
  range = begin_node.source_range
  # Removing an empty value puts the `#` right before what follows the interpolation.
  following = "#{value}#{source[range.end_pos]}"
  return false unless following.start_with?('{', '@', '$')
  return false unless source[range.begin_pos - 1] == '#'

  unescaped_hash_sign?(source[0...range.begin_pos])
end

# File 'lib/rubocop/cop/lint/literal_in_interpolation.rb', line 225

def unescaped_hash_sign?(text)
  text.end_with?('#') && text.delete_suffix('#')[/\\*\z/].length.even?
end