Fix handling when the error changes after a retry

[ashimomura]

Motivation / Background

This gem utilizes retry_on with ActiveSupport::Rescuable for implementation, but the behavior of ActiveSupport::Rescuable.rescue_with_handler has changed since ActiveSupport v5.2.

Since ActiveSupport 5.2, if no handler exists for the exception passed as an argument, it searches for a handler attached to the #cause of that exception.

https://github.com/rails/rails/blob/v5.2.0/activesupport/lib/active_support/rescuable.rb#L88-L101

Therefore, even when the exception changes after being retried due to a retryable exception,
it continues to be processed as a retryable exception because it searches for a handler attached to the #cause of the exception.

e.g.

class Example
  class RetriableError < StandardError; end
  class OtherError < StandardError; end

  include MyApiClient::Exceptions

  retry_on RetriableError, wait: 0.seconds, attempts: 2

  private

  def execute
    puts 'execute'
    unless @first_executed
      @first_executed = true
      raise RetriableError
    else
      raise OtherError
    end
  end
end

instance = Example.new
instance.call(:execute) # => 1. raised RetriableError, and retry
                        # => 2. raised OtherError, handler not found. but searches for a handler of `Exception#cause` that is RetryableError
                        # => 3. continues retry 

Detail

Override ActiveSupport::Rescuable.rescue_with_handler and pass Exception#cause to visited_exceptions to treat it as a "handled" exception.

[ryz310]

Thank you for your contribution!