gracefully.rb

class Gracefully
  class << self
    alias_method :handle, :new
  end

  attr_reader :error, :value

  def initialize
    @value = nil
    @error = nil
    begin
      @value = yield
    rescue => e
      @error = e
    end
  end

  def success?
    error.nil?
  end

  def on_success
    return self unless success?
    result = yield(@value)
    return result if result.is_a?(Gracefully)
    Gracefully.handle { result }
  end

  def on_failure
    return self if success?
    result = yield(@error)
    return result if result.is_a?(Gracefully)
    Gracefully.handle { result }
  end
end

test.rb

result = Gracefully.handle { ComplicatedService.new(foo, bar).process }
if result.success?
  # do success stuff
  use_value(result.value)
else
  # do failure stuff
  log_error(result.error)
end

Gracefully.handle { SomeComplicatedService.new.call }.on_success do |val|
  val.update!(column_name: 'stuff')
end

Gracefully.handle { SomeComplicatedService.new.call }.on_failure do |e|
  do_whatever_you_wish_with_the_error(e)
end