coerced_value_validator.rb

class CoercedValueValidator < ActiveModel::Validator
  def validate(record)
    coercible_attrs = record.keys.select { |k,v| [Integer, Float, Date, Time].include?(v.type) }.map(&:first)
    coercible_attrs.each do |attr|
      record.errors.add(attr, 'is invalid') if record.send("#{attr}_before_type_cast").present? && record.send(attr).nil?
    end
  end
end