Hash Rocket =>

I now understand => is Hash Rocket; yeah ruby!

Learn Enough Rails (7) training 4.3.3

irb may be outdated

The irb gem can be more advanced than the version that comes with the current ruby version on your system. You can add irb to your gemfile to use a newer version.

bundle add irb

Add months to a date with >>

In ruby you can add days to a date with the + method, and you can add months with >>:

require "date"
Date.today + 1
=> #<Date: 2023-07-11>

Date.today >>  1
=> #<Date: 2023-08-10>

How to spy on method calls in minitest

You can spy on a method in minitest with a Mock by calling #verify

mock = MiniTest::Mock.new
mock.expect :username

User.stub :find, mock do
  user = User.find(1)
  user.username
end

mock.verify

How to stub a method in minitest

In minitest you can stub a method my calling .stub and passing a method name:

class User
  def self.all
    42
  end
end

User.stub(:all, [1, 2, 3]) do
  assert_equal [1, 2, 3], User.all
end