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OCTOBER 1, 2022

Lucky begins the 1.0 ascent with the first release candidate

Lucky 1.0.0-rc1 has been released, and it's a huge milestone for the framework and community.

As many developers know, reaching a 1.0 milestone is huge, and something to be celebrated. We’re excited to publish the first release candidate of Lucky 1.0. We will be using this and the next few release candidates to clean up the rough edges of the framework, and make sure all of the dependencies in the Lucky ecosystem are solid and ready to take us to the next level.

We will cover a few notable differences, but you can view all the changes from the CHANGELOG

# How to upgrade


You can also view the changes using LuckyDiff. This tool helps see what has changed between versions and will be included in upgrade notes from now on.

# Here’s what’s new

This version releases several breaking changes that were needed in order to make the framework more extensible for the future.

# No more DB dependency

Many sites (including this one) have no need for a database. In some cases, your data comes from a 3rd party API, or maybe you need a custom database engine other than PostgreSQL.

In this release, Avram is no longer a dependency of Lucky, but instead, Lucky is now an optional dependency of Avram. If you’re using Avram outside of Lucky, then nothing changes for you. However, for existing Lucky users upgrading to rc1 that need Avram, you’ll now have to include it as an additional dependency. Be sure to add it to your shard.yml file, and require it in your src/

# Support for Array params in operations

Support for Arrays in Lucky and Avram have existed for a few versions now. This includes support for arrays in params. However, one bit that has been missing was the ability to pass those array params through to an operation.

For example:

# before this release
# post:tags[]=lucky&post:tags[]=crystal
tags = params.nested_arrays("post")["tags"]
SavePost.create(params, tags: tags) do |operation, post|
  # ...

# after this release
SavePost.create(params) do |operation, post|
  # ...

This ended up being quite a big breaking change. The original Params implementation assumed the type was Hash(String, String), but this meant you couldn’t have an array value. Now the type assumes Hash(String, Array(String)) which is actually the same type as URI::Params.

# Changes to the javascript Ecosystem

As we all know, the javascript ecosystem changes in leaps and bounds daily. This makes it very difficult to keep up.

In 2017, when Lucky began, the Rails core team had a neat library called Turbolinks. This library helped to make pages feel even faster, and who doesn’t love speed? Lucky included this library by default, but Rails has since deprecated Turbolinks in favor of Turbo. Although Lucky doesn’t include Turbo yet, we would still like to encourage users to give it a shot, and let us know if this is something you’d like to see included by default.

Along those same lines, Lucky also came out-of-the-box with Laravel-Mix which is “An elegant wrapper around Webpack”. This made bringing javascript to Lucky seamless, and easy. However, the Laravel framework has moved to Vite as their default front-end. Laravel-Mix may or may not stick around, but with the uncertainty, the 1.0.0-rc1 release opens up the possibility to use Vite while keeping with the type-safe traditions Lucky brings.

If you’d like to experiment with it, updated your src/, with this code

# src/
Lucky::AssetHelpers.load_manifest "public/manifest.json", use_vite: true

Then you’ll just need to setup Vite as your build system. For some examples, you can visit this Vite Lucky test app

So why even include a javascript build system with Lucky?

One of Lucky’s goals is to be type-safe and help catch bugs in development. This is done in many ways, but one of the most important ways is when it comes to loading your assets in production. By utilizing a generated manifest file, Lucky can generate an internal NamedTuple at compile-time that can be referenced in the app. When you forget to add an asset (i.e. image, style, script, etc…), a compile-time error will raise letting you know.

# Email layouts and callbacks

Carbon 0.3.0 has been released with a few neat updates. The first being the ability to set email layouts. Just like your standard views, you may have a very similar wrapper on your emails like contact footer info, or your logo.

To specify your layout, you’ll add the layout macro, and pass the name of the folder where your layout template file is located.

# src/emails/
class WelcomeEmail < BaseEmail
  def initialize(@recipient : Carbon::Emailable)

  to @recipient
  from ""
  subject "Welcome to the site!"
  layout my_email_layout
  templates html, text

Then in your templates, you can add my_email_layout/layout.ecr, and use the content method to yield your email body

# src/emails/templates/my_email_layout/layout.ecr
<h1>Our Email</h1>

<%= content %>


# src/emails/templates/welcome_email/html.ecr
<p>Welcome to the site!</p>

Emailing can be tricky. Sometimes it’s hard to track emails, and other times you’re dealing with unsubscribes. To help with these, we’ve added before_send and after_send callbacks, as well as a deliverable : Bool property. When deliverable is set to false, the email won’t be sent.

class FriendIsLiveEmail < BaseEmail
  def initialize(@recipient : Carbon::Emailable, @friend : User)

  before_send do
    if !@recipient.wants_email_from_friend?(@friend)
      self.deliverable = false

  # the response is from the email service (i.e. sendgrid, etc...)
  after_send do |response|, sent_at: Time.utc)

# More ORM updates

Working towards better compatibility with CockroachDB enums now support both Int64 values, as well as the @[Flags] annotations making bitwise permissions super easy to achieve in Lucky!

Another amazing update is the addition of the extract() query method for timestamp columns. This allows you to query for date parts of a Time object. For example, query for all users that signed up in July.

This extract method accepts any of the following chronounits:

enum ChronoUnits

We’ve also added support for the bytea column with Crystal’s Byte (Slice(UInt8)) alias.

# In your model
table do
  column data : Byte

# Parting words

Thank you to everyone that helped with this release, and welcome to all of the new people that have joined our Discord recently. It’s fun and exciting seeing all of the growth happening.

Please report any issues, and as always, PRs are greatly appreciated!

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If you have any questions, or just want to chat, please join us on Discord.