GeorgeBramus

  # было
  private def coincides?(card_original_text, custom_original_text)
    DamerauLevenshtein.distance(card_original_text.mb_chars.downcase.to_s, custom_original_text.mb_chars.downcase.to_s) < card_original_text.size * ALLOWED_TYPOS
  end
  
  # стало
  private def coincides?(:card_original_text, :custom_original_text)
    DamerauLevenshtein.distance(:card_original_text, :custom_original_text) < :card_original_text.size * ALLOWED_TYPOS
  end

GeorgeBramus

class CheckCardAndUpdate
  # ...

  def call
    card = Card.find(context.card_id)

    context.message = if coincides?(card.original_text, context.custom_original_text)
      correct_answer(card)
      'right'
    else

GeorgeBramus

  def check
    result = CheckCardAndUpdate.call(
        custom_original_text: params[:original_text],
        card_id: params[:id]
      )

    @misspelling = DamerauLevenshtein.distance(params[:original_text], Card.find(params[:id]).original_text)
    flash[:notice] = result.message
    redirect_to action: :index
  end

GeorgeBramus

class CheckCardAndUpdate
  include Interactor

  def call
    card = Card.find(context.card_id)

    context.message = if coincides?(card.original_text, context.custom_original_text)
      correct_answer(card)
      'Вы правильно ответили!'
    else