DEV Community: Jokūbas Pučinskas

Callbacky - bring callbacks to simple Ruby objects

Jokūbas Pučinskas — Tue, 03 Jun 2025 14:33:05 +0000

Hey folks! 👋

I just released a tiny Ruby gem called callbacky that brings declarative lifecycle callbacks (like before and after) to your plain Ruby objects — no Rails dependency required!
🚀 Why?

Sometimes you need a clean way to separate setup, teardown, or side-effects from core logic — like service objects, workers, or POROs. Inspired by Rails-style callbacks, Callbacky gives you a lightweight way to do this with methods, procs, or blocks.

✨ Features

Define before / after callbacks per lifecycle event (e.g., :init)

Supports method names, lambdas, or inline blocks

Chainable and extensible

Works with plain Ruby — no magic, no monkey patches

💡 Usage

class MyService
  include Callbacky

  callbacky :before, :init, :prepare
  callbacky :after, :init, ->(obj) { obj.log_done }

  callbacky :after, :init do |instance|
    instance.notify!
  end

  def initialize
    callbacky_init do
      puts "Doing work..."
    end
  end

  def prepare    = puts "Preparing..."
  def log_done   = puts "Logging done"
  def notify!    = puts "Notifying"
end

🛠 Open Source & Contributions Welcome

Check it out on GitHub 👉 github.com/pucinsk/callbacky
If you find it useful or have suggestions, I’d love your feedback and PRs!

3 useful VS Code extensions for testing Ruby code

Jokūbas Pučinskas — Fri, 08 Nov 2024 11:46:50 +0000

As VS Code wins as the most used Ruby code editor in 2024 Ruby on Rails Community Survey we are seeing more and more great tooling and extensions dedicated for Ruby appearing in VS Code extensions marketplace.

In this short blog post, I’d like to share my 3 favorite extensions that provide shortcuts for the testing part of the programming cycle.

Rails Run Specs

Link to an extension

Rails Run Specs provides commands which allow to run tests in a whole suite and file or by selected spec block.

Commands can be conveniently executed by pressing keyboard shortcut or from commands menu (cmd+shift+p). Everytime spec command runs it creates or reuses dedicated terminal session where you can see an output of running tests.

It supports both RSpec and Minitest as well as any other testing gem. There are flexible configurations options which allow to configure editor with needed testing tool.

Ruby Test Explorer

Link to an extension

This is a Ruby Test Explorer extension for the VS Code Test Explorer extension.

It allows to see all specs listed in an explorer view, run them by a few mouse clicks and quickly locate failures.

Extension supports both RSpec and Minitest gems.

Go To Test

Link to an extension

Quickly toggle between code and spec files. This extension is programming language agnostic and it works just fantastic with Ruby projects.

Extension provides keyboard shortcut to toggle between code and spec files. Loving it!

I hope that you'll find this list of extensions useful and interesting as I did! If you have your favorite testing extensions leave them in comment section below.
Thank you for reading!

Ruby exceptions: tips & tricks

Jokūbas Pučinskas — Sat, 02 Nov 2024 14:18:58 +0000

Exceptions are unexpected events that disrupt an application’s flow. Ruby’s exception-handling features make it easy to manage these errors, ensuring applications remain stable and user-friendly.

Here's an example of common exception handling flow in Ruby:

begin
  do_something # may raise an exception
  1/0 # raises an exception
rescue ZeroDivisionError => e
  # `ZeroDivisionError` exception handler
else
  # If no exceptions were raised
ensure
  # Code which always gets executed
end

In this article, I’ll share a few tips on effectively handling exceptions in Ruby to keep your applications running smoothly.

`fail` with error

fail is a lesser-known keyword for raising errors in an application. However, it adds clarity to the code when you want it to explicitly fail and the program to exit.

Let's see an example:

begin
  fail "The weather is too bad for this code to work."
rescue
  puts "I'll try tomorrow."
  exit 0
end

In this example, fail raises an error just like raise does. However, fail conveys a clearer intention from the developer for the application to fail.

`rescue` with multiple exceptions

rescue statement shares simillar syntax to case operator.

case foo
when Number, Decimal
  puts "It is a number"
when String
  puts "It is a string"
end

begin
  do_something
rescue NoMethodError, NameError
  puts "Method or variable is not defined"
rescue RuntimeError
  puts "Runtime error occured"
end

This allows for clear handling of various error scenarios while maintaining readability in the code.

Rescueing from `Exception`

The Exception class is the base of Ruby's exception hierarchy. Therefore, when you rescue Exception, you are effectively rescuing from all Ruby built-in exceptions, including its subclasses like SyntaxError, LoadError, and Interrupt.

begin
  do_something
rescue Exception => e # bad
rescue => e # bad
end

`Exception#cause`

In Ruby, we can always rescue and raise another exception, which is a common pattern. The Exception#cause method allows you to check if an exception was raised by another exception, and if so, it enables you to trace it back, making it easier to debug the code.

begin
  begin
    1/0
  rescue
    raise RuntimeError
  end
rescue => e
  puts e.class
  puts e.cause.class
end
# Output:
RuntimeError
ZeroDivisionError

Current exception with `$!`

Ruby stores current exception in a $! variable which you can access in a code or whilst in a debuggig session in console.

begin
  raise RuntimeError, "It's hammertime"
rescue RuntimeError
  puts $!.message
end
# Outputs:
"It's hammertime"

In this short post, we explored several tips for effective exception handling in Ruby. Using fail for clear error signaling, managing multiple exceptions with rescue, and leveraging Exception#cause for tracing errors are all strategies that enhance code readability and maintainability.

Thank you for reading and see you next time 🚀

DEV Community: Jokūbas Pučinskas

Callbacky - bring callbacks to simple Ruby objects

3 useful VS Code extensions for testing Ruby code

Rails Run Specs

Ruby Test Explorer

Go To Test

Ruby exceptions: tips & tricks

fail with error

rescue with multiple exceptions

Rescueing from Exception

Exception#cause

Current exception with $!

`fail` with error

`rescue` with multiple exceptions

Rescueing from `Exception`

`Exception#cause`

Current exception with `$!`