Don't call gsub on safe strings

Capybara allows you to select DOM elements, e.g. by using field, find_field(...) or field_labeled(...):

role_select = field_labeled('Role')

In the example above, role_select is now a Capybara::Driver::Node. You can call a [number o...

You cannot use Array#join on an array of strings where some strings are html_safe and others are not. The result will be an unsafe string and will thus be escaped when rendered in a view:

unsafe_string = '<span>foo</span>'
safe_string...

If you have an html_safe string, you won't be able to call gsub with a block and match reference variables like $1. They will be nil inside the block where you define replacements ([as you already know](https://makandracards.com/makandra/2...

When I upgraded from 0.5.4 PDFKit deadlocked or crashed when an ApplicationController::RouteError occured. If this error happens only because of a broken image link you probably still wan't the page to render and get a PDF with a "missing image pl...

Bad

# Given the following models

class Image < ActiveRecord::Base
  has_many :album_images
  has_many :albums, through: :album_images
end

class Album < ActiveRecord::Base
  has_many :album_images
  has_many :images, through: :album_i...

When you develop a gem and you have a Gemfile in your project directory, you might be surprised that your gem dependencies aren't already required in your specs. Here is some info that should help you out:

• Bundler actually doesn't automatical...

Do not pass times to date attributes. Always convert times to dates when your application uses time zones.

Background

A time-zoned Time attribute on a Rails record is converted to UTC using to_s(:db) to be stored, and converted back into t...

When you find yourself constantly ignoring a RubyMine warning, you can simple disable that warning and de-clutter your editor. E.g. in my Cucumber scenarios RubyMine underlines 90% of all lines because it does not know about [spreewald](https://gi...

Sometimes it is useful to define a named scope by implementing a static method with the scope's name on the scoped class. For instance, when a method should decide which existing scope should be the next link in the scope chain. Take this class fo...

It might sound trivial, but there is no such thing as a "hover" or "mouseover" state on touch devices. If your application is supposed to work on iPads, smartphones, etc., don't hide information behind a tooltip, and don't make controls appear whe...