discourse/lib/validators/timezone_validator.rb

# frozen_string_literal: true

class TimezoneValidator < ActiveModel::EachValidator
  def self.valid?(value)
    ok = ActiveSupport::TimeZone[value].present?
    Rails.logger.warn("Invalid timezone '#{value}' detected!") if !ok
    ok
  end

  def self.error_message(value)
    I18n.t("errors.messages.invalid_timezone", tz: value)
  end

  def validate_each(record, attribute, value)
    return if value.blank? || TimezoneValidator.valid?(value)
    record.errors.add(
      attribute,
      :timezone,
      message: TimezoneValidator.error_message(value)
    )
  end
end