Find records with a Range condition

Use this scope:

class Stick
  named_scope :shuffled, lambda {
    last_record = last
    { :conditions => [ 'id >= ?', rand(last_record.id) ] } if last_record
  }
end

You can now pick a random stick by saying

Stick.s...

When you have objects in your database that hold latitude and longitude and you want to find others that are close to given coordinates you can use the Graticule gem.

Graticule

Graticule of...

If (for some reason that you don't want to ask yourself) you need to know all classes that define a method with a given name, you can do it like this:

def classes_defining_method(method_name)
  method_name = method_name.to_sym
  Objec...

When you need to insert many records into the same table, performance may become an issue.

What you can do to save time is to open a transaction and save multiple records within that transaction:

transaction do
  500.times { Model.create!...

Imagine these models and associations:

class Deck < ApplicationRecord
  has_many :cards
end

class Card < ApplicationRecord
  belongs_to :deck, optional: true
end

Now you want to find all Decks without any Card or all Cards without a...

Capybara has a variety of finder methods like find_button to help you look up DOM elements. There are also matchers ...

Simplecov is a code coverage tool. This helps you to find out which parts of your application are not tested.

Integrating this in a rails project with rspec, cucumber and parallel_tests is easy.

1. Add i...

Recently I needed to benchmark an Active Record query for performance measurements. I wrote a small script that runs each query to benchmark 100 times and calculates the 95th percentile.

Note: The script requires sudo permissions to drop RAM cach...

The state_machine gem ships with a scope with_state. This scope has some problems in complex queries or scope chains.

Use this instead:

named_scope :having_state, lambda { |*state_or_states|
  state_or_states = Array.wrap(state_or_stat...

Find-as-you-type boxes are usually built by observing changes in a text field, and querying the server via AJAX for search results or suggestions when the field has changed.

A common problem with this implementation is that there is no guarantee ...