Using singleton objects as default arguments in Ruby

Sometimes you would like to define a method which takes an optional argument, but the programmer might pass nil. And your code needs to distinguish between the value not being provided (default value) and nil. How can it be achieved?

User.find_by(email: “greg.stephan@gmail.com”) is easier to find the documentation for “find_by” (or navigate in IDE), equally readable and does not involve any kind of magic. That’s what ActiveRecord went towards.

As for instance variables being copied, convinient until you don’t use all of them (and there are many) and you…

Guide to setup testing React.js components with Jest in Rails+Webpacker+Webpack environment

Around a month ago, I worked on a task, which required a more dynamic frontend behavior. I worked on a component with 2 selects and 2 date pickers and depending on what was…