Undefined method `each_with_index'

Support dry-validation
1

Hi
Let’s say I have this form:

class Form < Dry::Validation
  params do
    optional(:phones).maybe do
      each do
        hash do 
          required(:id).filled(:integer)
          required(:names).filled(:array, min_size?: 1) do 
             each(:integer)
          end
        end
      end
    end
  end

  rule(:phones).each do |index:|
    if values[:phones][index].dig(:id)
      key([:phones, index, :id]).failure("doesn't exist") unless check_id(values[:phones][index][:id])
    end
  end
end

given data:

data = {phones: nil}

I get an error when I try to validate my form:

form = Form.new
form.call(data) => Undefined method `each_with_index'

Do you know how Can I overcome this problem? I want phones to accept nil value. I’ve been thinking about overwriting #rule method but I don’t know where to start.

Thanks in advance!