Rails%203%20In%20Action

380 CHAPTER 13 Designing an API
13.3.3 Back to zero
15 Not really.
You need to reset the request_count of each user who’s made a request to your API.
This will be a method on the User model, and so you’ll put its test in a new file as
spec/models/user_spec.rb file, inside the describe User block, using the code from
the following listing.
Listing 13.28 spec/models/user_spec.rb
require 'spec_helper'
describe User do
it "resets user request count" do
user = Factory(:user)
user.update_attribute(:request_count, 42)
User.reset_request_count!
user.reload
user.request_count.should eql(0)
end
end
With this spec, you set a new user’s request count to something other than 0; 42 is a
random number, 15 and you’re quite fortunate for it to exist so that you can use it. The
reset_request_count! method isn’t defined, but as the remainder of the test implies,
the user’s request count should be 0. This test, unsurprisingly, will not pass when it
runs, and so you should write the method to make it pass.
As the reset_request_count! method is called on User, you define this method in
app/models/user.rb using the following code above the to_s method:
def self.reset_request_count!
update_all("request_count = 0", "request_count > 0")
end
You’re placing this code right above the to_s method because it is best practice to
place class methods (such as reset_request_count!) above instance methods in a
model, as some instance methods may refer to class methods. Also, if everybody puts
their code in logical places, then you won’t be confused when you look at it, which is
what Rails is all about.
The update_all method here will set the request_count on all user records (the
first argument) that have a request_count > 0 (the second argument), or a request
_count greater than zero. No point resetting counts that are zero back to zero.
Now that the reset_request_count! method is defined, does it work as your test
says it should? Well, let’s run bin/rspec spec/models/user_spec.rb:
1 example, 0 failures
Cool, so now you’ve got the request count being reset for all users whenever this
method is called. You’ll take a look at calling this method automatically when we look
at background jobs in chapter 15.