Machinist blueprints do not work with a column :display

TL;DR In blueprints, always wrap associations in blocks.

# Broken
Task.blueprint(:vacation) do
  project Project.make(:vacation)
  hours 8
  accounting_method 'none'
end

# Correct
Task.blueprint(:vacation) do
  project { Project....

Note: We are talking about Machinist 1 here, Machinist 2 may have solved this or might require a different approach.

Machinist allows named bluep...

Sometimes we write plain SQL queries in migrations so we don't have to mock ActiveRecord classes. These two migrations do the same:

class Migration1 < ActiveRecord::Migration[5.2]
  class User < ActiveRecord::Base; end

  def up
    add_c...

Imagine you have 2 HTML boxes. The first one has a margin-bottom of let's say 30px and the second one a margin-top of 20px. After rules of collapsing margins have been applied we ha...

Imagine you want to write a cucumber test for a user-to-user chat. To do this, you need the test to work with several browser sessions, logged in as separate users, at the same time.

Luckily, Capybara makes this relatively easy:

Scenario:

S...

Today I needed to execute a ruby gem executable with sudo. But, surprisingly, bash would tell me command not found for the gem that ran lovely without sudo.

Gem bins are installed to /var/lib/gems/1.8/bin, which is not in sudo’s PATH....

Association named 'variations' was not found; perhaps you misspelled it?

I just was hunting down a strange error with this model:

class Model
  placeholder = 'variations'
  
  has_many placeholder
  
  nested_scope :v...

This is a problem when using Selenium with Firefox. We recommend using ChromeDriver for your Selenium tests.

Firefox will not trigger focus/blur events when its window is not focused. While this makes sense in standard usage, it...

Don't sum up columns with + in a sql-query if NULL-Values can be present.

MySQL and PostgreSQL cannot sum up NULL values with the + value. The sum value will be NULL.

MySQL:

mysql> select 1 + 2 + 3;
+-----------+
| 1 + 2 + 3 |
+--...