Use create_or_find_by to avoid race condition in Rails 6.0

It’s pretty common in Ruby on Rails to use find_or_create_by method when you want to create a new record if the record isn’t already existed:

> User.find_or_create_by(username: "sikachu")
  User Load…

Private Attribute Accessor in Ruby is An Artifact from Other Languages

I’ve recently started seeing a trend of defining a private attr_accessor in Ruby code, and I honestly seeing them as an artifact from other programming languages. It’s something that followed the developer…

Squishing your multiline SQL queries for cleaner log output

When you are developing a complex Ruby on Rails application, you might need to write a few SQL queries and avoid using Active Record and ARel to improve your application’s throughput. It’s pretty common to see them written…

A Faster Way to Exit Pry Session

If you are using Pry in your project, you might run into situation where you are in a loop or having multiple binding.pry and so you have to use exit multiple times to get out from it.

Relation.pick in Rails 6.0

Back in 2012, Rails 3.2.0 added a .pluck method which you can call on a ActiveRecord::Relation or a model class:

> User.pluck(:id)
#=> [1, 2, 3]

But what if you need just the first value from the result? You will probably have to…

A new helper to freeze time in Rails 5.2

This one is a simple quality-of-life improvement.

N’EX (Narita Express) Seating Chart

Here’s the seating chart of N’EX:

It’s Better to Write a Thread-Safe Code

I recently having a discussion with my colleague about a class variable in one of the pull request. He proposed a commit which includes a code that uses a class variable. I suggested that we should use a Thread.current to store that value instead for thread…

Private delegation method in Rails 6.0

Since Rails 2.1.0, Rails provides a helper method delegate as a shorthand to create simple delegation methods:

# This code
delegate :email, :name, to: :profile
delegate :title, to: :@post, prefix: true

Think twice before using double splat in Ruby

As of Ruby 2.5.1, double splat operator (**options, for example) is still considerably slower than accepting a normal argument and sets a default to empty hash.