created birth date validator

app/validators/contact/ident/birth_date_validator.rb

@@ -0,0 +1,26 @@
+class Contact::Ident::BirthDateValidator < ActiveModel::Validator
+  VALID_BIRTH_DATE_FROM = Time.zone.today - 150.years
+  VALID_BIRTH_DATE_TO = Time.zone.tomorrow
+
+  def validate(record)
+    record.errors.add(:code, :invalid_birth_date) if birth_date_wrong?(record)
+  end
+
+  private
+
+  def birth_date_wrong?(record)
+    return unless record.birthday?
+
+    begin
+      Date.parse(record.code)
+    rescue ArgumentError
+      return true
+    end
+
+    contact_ident_date = Date.parse(record.code)
+    valid_time_range = VALID_BIRTH_DATE_FROM...VALID_BIRTH_DATE_TO
+    return if valid_time_range.cover?(contact_ident_date)
+
+    true
+  end
+end