EnumKit

EnumKit provides native support for PostgreSQL enums in Ruby on Rails projects.

Installation

You can install EnumKit using the following command:

$ gem install enum_kit

Or, by adding the following to your Gemfile:

gem 'enum_kit', '~> 0.1'

Usage

Here's a sample migration file which creates the enum :shirt_size, then adds the column :size to the :shirts table using the :shirt_size enum as the underlying type:

class CreateShirts < ActiveRecord::Migration[6.0]
  def change
    create_enum :shirt_size, %i[small medium large]

    create_table :shirts do |t|
      t.string :name
      t.enum   :size, name: :shirt_size

      t.timestamps
    end
  end
end

You can remove the enum later using something similar to this:

class DropShirts < ActiveRecord::Migration[6.0]
  def change
    drop_table :shirts
    drop_enum  :shirt_size
  end
end

Once you've defined an enum in a migration file, you can use it in the associated model:

class Shirt < ActiveRecord::Base
  pg_enum :size
end

Note that you don't need to define the enum's cases again. The pg_enum method automatically queries the database when Rails boots for the acceptable values!

---

When setting the enum to an unsupported value, an exception is raised. This can be problematic in cases where you don't have control over the input (such as when using APIs).

To improve this, you can optionally specify that exceptions should not be raised on a per enum basis. Note that when opting for this feature, you'd ideally specify a validation to capture any unsupported values:

class Shirt < ActiveRecord::Base
  pg_enum :size, exceptions: false

  validates :size, pg_enum: true
end

The above prevents exceptions from being raised and checks that the assigned value is one of the cases supported by the enum.

Development

After checking out the repo, run bundle exec rake spec to run the tests.

To install this gem onto your machine, run bundle exec rake install.