Nilify Blanks

In Rails when saving a model from a form and values are not provided by the user, an empty string is recorded to the database instead of a NULL as many would prefer (mixing blanks and NULLs can become confusing). This gem converts blank attributes to nil before a model is saved, either for every applicable column or for a list you choose.

By default, columns set as NOT NULL will not be nilified, since that value cannot be persisted, and it might be better to catch that with a validation. If you want to nilify those columns anyway, you can use only: (see below) to explicitly mention them.

Only attributes responding to blank? with a value of true will be converted to nil. Therefore, this does not work with integer fields with the value of 0, for example.

Rails 7.1 added normalizes, which handles the per-attribute case well:

class Post < ApplicationRecord
  normalizes :title, :author, with: ->(value) { value.presence }
end

normalizes applies on assignment (not just before save) and to finder queries like where(title: ""), so prefer it when you only care about a few attributes.

Use nilify_blanks when you want this behavior for every nullable string/text column without listing them, including columns added later, or across all models at once via ApplicationRecord or ActiveRecord::Base.

• Rails (Active Record) 6.1 or newer
• Ruby 2.7 or newer

Version 1.4.0 remains available for older Rails versions.

Add the gem to your Gemfile:

gem "nilify_blanks"

# Checks and converts all nullable string, text and citext columns
class Post < ApplicationRecord
  nilify_blanks
end

# Checks and converts only text columns
class Post < ApplicationRecord
  nilify_blanks types: [:text]
end

# Checks and converts only the title and author fields
class Post < ApplicationRecord
  nilify_blanks only: [:author, :title]
end

# Checks and converts all fields except for title and author
class Post < ApplicationRecord
  nilify_blanks except: [:author, :title]
end

# Checks and converts any fields, regardless of their null constraint
class Post < ApplicationRecord
  nilify_blanks nullables_only: false
end

You can apply nilify_blanks to every model in your application:

class ApplicationRecord < ActiveRecord::Base
  self.abstract_class = true
  nilify_blanks
end

Or to all models inheriting from ActiveRecord::Base:

ActiveRecord::Base.nilify_blanks

Or perhaps just a model namespace base class:

Inventory::Base.nilify_blanks

Individual models can still call nilify_blanks with their own options to override the inherited configuration.

Checking uses an Active Record before_validation callback by default, but you can specify a different callback with the :before option. Any before_* callback will work; just remove the before_ prefix from the name.

class Post < ApplicationRecord
  nilify_blanks before: :save
end

class Post < ApplicationRecord
  nilify_blanks before: :create
end

First, include the matchers:

require "nilify_blanks/matchers"

To ensure for a given column:

RSpec.describe City do
  it { is_expected.to nilify_blanks_for(:name) }
end

To ensure for all applicable content columns:

RSpec.describe City do
  it { is_expected.to nilify_blanks }
end

You can optionally match on options also:

RSpec.describe City do
  it { is_expected.to nilify_blanks_for(:name, before: :create) }
  it { is_expected.to nilify_blanks(before: :create) }
end

bundle install
bundle exec rake

CI runs the suite against each supported Rails version using the gemfiles in gemfiles/. To run against one locally:

BUNDLE_GEMFILE=gemfiles/rails_7.2.gemfile bundle install
BUNDLE_GEMFILE=gemfiles/rails_7.2.gemfile bundle exec rake