JunkDrawer

JunkDrawer is a gem providing a handful of random utility that are commonly useful across projects.

Installation

Add this line to your application's Gemfile:

gem 'junk_drawer'

And then execute:

$ bundle

Or install it yourself as:

$ gem install junk_drawer

If you want to include the Rails utilities, in your Gemfile you can instead use:

gem 'junk_drawer', require: 'junk_drawer/rails'

Contents

• JunkDrawer
  • Installation
    • Contents
  • Usage
    • JunkDrawer::Callable
    • JunkDrawer::Notifier
  • Rails
    • JunkDrawer::BulkUpdatable
      • Caveats
  • Development
  • Contributing
  • License

Usage

JunkDrawer::Callable

JunkDrawer::Callable is a module that provides constraints and conveniences for objects that implement a single method #call. It comes with the philosophy that objects that do something, should do only one thing. When including the JunkDrawer::Callable in one of your classes, you will get the following:

1. It raises an error if you try to implement a public method other than #call.

class Foo
  include JunkDrawer::Callable
  def bar # Bad: can't define public method "#bar"
  end
end

produces:

JunkDrawer::CallableError: invalid method name bar, only public method allowed is "call"

Private methods are fine:

class Foo
  include JunkDrawer::Callable
private
  def bar # private methods are okay!
  end
end

2. It delegates call on the class to a new instance:

class Foo
  include JunkDrawer::Callable
  def call(stuff)
    puts "I am a Foo! I've got #{stuff}"
  end
end

> Foo.call('a brochure')
I am a Foo! I've got a brochure
> Foo.new.call('a brochure')
I am a Foo! I've got a brochure

3. It implements to_proc, both on the class and instance, allowing operations such as:

> ['puppies', 'a cold', 'cheeseburgers'].each(&Foo)
I am a Foo! I've got puppies
I am a Foo! I've got a cold
I am a Foo! I've got cheeseburgers

See here for a great explanation of to_proc and the & operator:

http://www.brianstorti.com/understanding-ruby-idiom-map-with-symbol/

---

JunkDrawer::Notifier

JunkDrawer::Notifier is a class that provides simple notification strategies for different environments. When you call it, it will send a notification via your selected strategy. The strategies available are as follows:

1. :raise raises an error when you call the notifier:

JunkDrawer::Notifier.strategy = :raise
JunkDrawer::Notifier.call('some message', some: 'context')

produces:

JunkDrawer::NotifierError: some message, context: {:some=>"context"}

2. :honeybadger will send a notification to Honeybadger. You'll need to make sure you have Honeybadger required in your application and configured for this to work.

3. :null is a noop. If you want to disable notifications temporarily, you can configure the strategy to :null.

4. To create your own custom notifier, configure JunkDrawer::Notifier with a callable object as the strategy.

class MyNotifier
  include JunkDrawer::Callable

  def call(*args)
    SomeMonitoringService.notify(*args)
  end
end

JunkDrawer::Notifier.strategy = MyNotifier

JunkDrawer::Notifier.strategy = ->(*args) {
  MonitoringServiceA.notify(*args)
  MonitoringServiceB.notify(*args)
}

If you're using Rails, you may want to configure Notifier based on the environment, so in your config/environments/development.rb you might have:

config.after_initialize do
  JunkDrawer::Notifier.strategy = :raise
end

While in production.rb you might want:

config.after_initialize do
  JunkDrawer::Notifier.strategy = :honeybadger
end

---

Rails

For Rails specific tools, instead of requiring 'junk_drawer', you can require 'junk_drawer/rails'. This will pull in both the plain Ruby and the Rails specific utilities.

JunkDrawer::BulkUpdatable

JunkDrawer::BulkUpdatable is a utility to enable bulk updating of ActiveRecord models. To enable it, extend in your models:

class MyModel < ApplicationRecord
  extend JunkDrawer::BulkUpdatable
end

If you want to enable it for all models, you can also add it to your ApplicationModel class:

class ApplicationRecord
  self.abstract_class = true
  extend JunkDrawer::BulkUpdatable
end

To make use of it, you can pass an array of records into the .bulk_update class method on your model:

my_model_1 = MyModel.find(1)
my_model_1.name = 'Jabba'
my_model_2 = MyModel.find(2)
my_model_2.name = 'JarJar'

MyModel.bulk_update([my_model_1, my_model_2])

This will generate a single SQL query to update both of the records in the database. If prepared_statements is set to true, BulkUpdatable will generate queries that use bind parameters.

Caveats

• Right now this only supports PostgreSQL. PR's welcome!

• It also only supports basic data types (including hstore and jsonb) for your columns, so if you've got something weird you may have a bad time. Also PR's welcome!

• General advice: if you're updating many thousands of records at the same time, you may still run into some performance bottlenecks. When you're dealing with massive amounts of data, we suggest pairing JunkDrawer::BulkUpdatable with Rails' built-in find_in_batches:

  MyModel.find_in_batches(batch_size: 250) do |batch|
    batch.each { |my_model| my_model.name = 'Jar' * rand(100) }
    MyModel.bulk_update(batch)
  end

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests, or bin/test to run tests for all supported ActiveRecord versions. 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.

In order to run tests against different Rails versions, you can use BUNDLE_GEMFILE:

$ BUNDLE_GEMFILE=gemfiles/rails_7.0.gems rake spec

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/thread-pond/junk_drawer. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.