Lucky is Getting Bigger and Better: Announcing v0.6

Paul Smith

Lucky is a web framework written in Crystal that helps you build apps quickly, catches bugs for you, and runs incredibly fast.

I’ve been blown away by all the progress that has been made in the last month thanks to many new contributors. 👊

We’ve added over 130 commits and 20+ new features across the Lucky libraries since the initial announcement. The website has also been improved with a new Why Lucky? page, and some fresh new guides. All these changes bring us closer to production ready version of Lucky.

👋 Hey! If you’re interested in helping out with Lucky, or just want to see what’s new, check out Lucky’s GitHub repo.

Highlights in this release

Negate queries with not:

# Get users who don't work at Facebook

# Can be chained"Mc%")

Virtual fields for when you want users to fill something out, but not save to the database:

class SignUpForm < User::BaseForm
  # This is a field users should fill in, but is not saved to the database
  allow_virtual password_confirmation : String

Virtual forms were added so you can process data that isn’t ever saved to a database:

class SignInForm < LuckyRecord::VirtualForm
  allow_virtual email : String
  allow_virtual password : String

  def self.submit
    # authenticate the user

Tons of new migration helpers

# An example of a few of the new methods
def migrate
  create users do
    # Add indices at the same time as adding a field
    add company_id : Int32, index: true
    # Add unique indexes
    add email : String, unique: true
    # Set default values
    add admin : Bool, default: false

  # Create foreign keys with cascading deletes
  create_foreign_key :users, :companies, on_delete: :cascade

Improved logger in development

New JSON serializers

class Api::Users::Show < ApiAction
  action do
    user =

class Users::ShowJSON < LuckyWeb::Serializer
  # This is a shortcut for setting instance vars in Crystal
  def initialize(@user : User); end

  def render
    { name:, email: }

Other additions

And more! See the comparison view below if you want to see a comprehensive list of changes.

All changes in this release