class RSpec::Matchers::BuiltIn::Include

def diff_would_wrongly_highlight_matched_item?
  return false unless actual.is_a?(String) && expected.is_a?(Array)
  return false if Regexp === expecteds.first
  lines = actual.split("\n")
  expected.any? do |str|
    actual.include?(str) && lines.none? { |line| line == str }
  end
end