samuelgiles / there_was_an_attempt

A small utility designed to be used alongside Dry::Monads::Result to repeatedly attempt an operation sleeping between failed attempts.

There was an attempt

A small utility designed to be used alongside Dry::Monads::Result to repeatedly attempt an operation sleeping between failed attempts.

Installation

Add this line to your application's Gemfile:

gem 'there_was_an_attempt'

And then execute:

$ bundle

Or install it yourself as:

$ gem install there_was_an_attempt

Usage

Without any arguments given to the constructor a basic backoff interval (2, 4, 8, 16 to be precise) is used with sleep being used to wait, as a nicety this is available as .attempt:

# Shortcut for: ThereWasAnAttempt.new.attempt
ThereWasAnAttempt.attempt do
    Dry::Monads::Success(true)
end

You can specify your backoff intervals manually:

ThereWasAnAttempt.new(intervals: [1,2,4,8]).attempt do
    Dry::Monads::Success(true)
end

You can optionally specify your own "wait" logic. This might be useful for logging & tracking your retries:

ThereWasAnAttempt.new(
    intervals: [1,2,4,8],
    wait: ->(seconds) { puts seconds; sleep seconds }
).attempt do
    Dry::Monads::Success(true)
end

And more importantly you can optionally specify your own "reattempt" condition so as to only retry when the condition is true. This is really useful for dealing with network requests when you might only want to retry for specific network errors and works great when combined with Dry::Monads::Try.

ThereWasAnAttempt.new(
    reattempt: -> (failure) { failure.is_a?(Net::HTTPRetriableError) }
).attempt do
    Dry::Monads::Try(Net::HTTPExceptions) do
        Dry::Monads::Success(true)
    end.to_result
end

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/samuelgiles/there_was_an_attempt.