DefRetry

An expressive, fully spec'd gem to add the Retry Pattern to your methods and/or objects. With DefRetry you can define methods with retry logic built-in or you can wrap your code in a retry and specify options to customize the behavior.

Installation

Add this line to your application's Gemfile:

gem 'def_retry'

And then execute:

$ bundle

Or install it yourself as:

$ gem install def_retry

Usage

Defining a retryable method

require 'def_retry'

class ApiWrapper
  include DefRetry

  def_retry :get_data, on: ApiError do |*args|
    do_api_call
  end
end

This will define an instance method named get_data and rescue the exception ApiError and retry the block:

do |*args|
  do_api_call
end

3 times (the default).

Any arguments passed to the get_data(*args) method will get passed to the block.

Retrying a block of code

require 'def_retry'

class ApiWrapper
  include DefRetry

  def get_data
    @some_state = 'start'

    retryable on: ApiError do
      @some_state = 'working'
      do_api_call
      @some_state = 'done'
    end
  end
end

This will retry just that block of code.

Don't want to mixin?

Use DefRetry.retry directly:

require 'def_retry'

DefRetry.retry on: ApiError do
  do_api_call
end

Create a Retrier with default options

# config/intializers/retrier.rb
Retrier = DefRetry::Retrier.new({
  on: [ApiError, Timeout],
  tries: 7,
  on_retry: ->(exception, try_count) { Logger.debug exception },
  on_ensure: ->(value, try_count) { Logger.debug value, try_count },
  sleep: :exponential,
  re_raise: false
})

# later...
Retrier.run { do_api_call }

Options

These apply to .def_retry, #retryable, DefRetry.retry, and DefRetry::Retrier.new:

• :on: A single class or an array of exception classes to be rescued.
• :tries: Integer number of maximum retries to run. DefRetry will stop retrying if the retry count reaches this number.
• :sleep: Either an Integer to pass to sleep, a Proc that receives the current try count as its only argument or a Symbol naming one of these sleep strategies: constant, linear, exponential (see: DefRetry::Retrier::SLEEP_STRATEGIES).
• :on_retry: A callback to run every time a retry happens i.e. the specified exception(s) are rescued. It will receive the exception that was rescued and the current try count as arguments, respectively.
• :on_ensure: A callback to run at the end before returning the block's value. It will receive the block's return value and the current try count as arguments, respectively.
• :re_raise: (default true) re raise the exception after done retrying.

Contributing

1. Fork it ( https://github.com/DiegoSalazar/def_retry/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request