testing a has_one relationship? - ruby-on-rails

I have an object
class User < ActiveRecord::Base
has_one :subscription
end
and I have this test:
it "should increment shipped count when item_shipped" do
#user.attributes = #valid_attributes
#user.save
subscription = mock_model(Subscription)
subscription.stub!(:item_shipped!)
subscription.stub!(:user_id)
#user.subscription = subscription
lambda{#user.item_shipped!}.should change{#user.shipped_count}.by(1)
end
But I am getting an error:
1)
Spec::Mocks::MockExpectationError in 'User should increment shipped count when item_shipped'
Mock "Subscription_1113" received unexpected message :[]= with ("user_id", 922717357)
./spec/models/user_spec.rb:29:
I am not sure how to mock this out and I can't seem to find any references to this kind of thing.

Instead of mocking Subscription, try stubbing out the methods on an actual Subscription instead:
subscription = Subscription.new
subscription.stub!(:item_shipped!)
subscription.stub!(:user_id)
#user.subscription = subscription
Mocks can be brittle. Any call to a mock must be anticipated and declared as an expectation. It doesn't appear that this particular test needs that model mocked in any case.
EDIT: Also remember to declare any return values that the calling class depends on. In your case this might look like:
subscription.stub!(:item_shipped!).and_return(true)
subscription.stub!(:user_id).and_return(#user.id)
etc.
Again, if you're not asserting that a method on your mocked model should be called, then the only thing mocking does here is make your test brittle. Mocks are meant for things like:
subscription.should_receive(:some_method).once
Otherwise you simply need to stub out methods that have undesirable side effects that don't concern your spec.

Setting up associations for tests is made easier with factories: (untested)
Factory.define :subscriber, :class => User do |f|
f.name "Moe Howard"
f.association :subscription, :factory => :subscription
end
Factory.define :subscription, :class => Subscription do |f|
end
it "should increment shipped count when item_shipped" do
#user = Factory.create(:subscriber)
lambda{#user.item_shipped!}.should change{#user.shipped_count}.by(1)
end
Of course you're not really testing the association here -- you're testing the item_shipped method, which is what you really wanted.

change: mock_model(Subscription) to mock_model(Subscription).as_null_object
which will allow for any messages to be sent to the object (assuming this is an acceptable behavior in your case)

Related

Testing has_many association with RSpec

I'm trying to test the Hour model with RSpec, namely the class method 'find_days_with_no_hours' that behaves like a scope. Business has_many Hours associated through STI.
find_days_with_no_hours needs to be called through a Business object and I can't figure out how to set this up in the RSpec test.
I want to be able to test something like:
bh = #business.hours.find_days_with_no_hours
bh.length.should == 2
I've tried various approaches, like creating a Business object (with, say, Business.create), then setting #business.hours << mock_model(BusinessHour, ..., ..., ...) but that doesn't work.
How is this normally done?
class Business < ActiveRecord::Base
has_many :hours, :as => :hourable
end
class Hour < ActiveRecord::Base
belongs_to :hourable, :polymorphic => true
def self.find_days_with_no_hours
where("start_time IS NULL")
end
end
You can't test an arel method by creating the object via mocks. Arel is going to go straight into the database, and not see any mocks or anything that you've created in memory. I would grab factory_girl and then define an hour factory for yourself:
Factory.define :hour do |f|
f.start_time {Time.now}
end
Factory.define :unstarted_day, :parent => :hour do |f|
f.start_time nil
end
And then in your test...
business = Factory.create(:business)
business.hours << Factory.create(:unstarted_day)
bh = business.hours.find_days_with_no_hours
bh.length.should == 1
However, factory_girl is just a personal preference for setting up known state, you can just as easily use create statements or fixtures, the problem for you was trying to use mock_model() (which prevents a database hit), and then using a method that queries the database.

Dependent factories in Factory Girl

I have 2 factories. Beta_user and Beta_invite. Basically before a Beta_user can validly save I have to create an entry of Beta_invite. Unfortunately these models don't have clean associations, but they do share an email field.
Factory.sequence :email do |n|
"email#{n}#factory.com"
end
#BetaInvite
Factory.define :beta_invite do |f|
f.email {Factory.next(:email)}
f.approved false
f.source "web"
end
#User
Factory.define :user do |f|
f.email {Factory.next(:email)}
f.password "password"
end
#User => BetaUser
Factory.define :beta_user, :parent => :user do |f|
f.after_build do |user|
if BetaInvite.find_by_email(user.email).nil?
Factory(:beta_invite, :email => user.email)
end
end
end
So in the beta beta_user factory I am trying to use the after_build call back to create the beta_invite factory.
However it seems to be acting async or something. Possibly doing the find_by_email fetch?
If I try this:
Factory(:beta_user)
Factory(:beta_user)
Factory(:beta_user)
I get a failure stating that there is no record of a beta_invite with that users email.
If instead I try:
Factory.build(:beta_user).save
Factory.build(:beta_user).save
Factory.build(:beta_user).save
I get better results. As if calling the .build method and waiting to save allows time for the beta_invite factory to be created. Instead of calling Factory.create directly. The docs say that in the case of calling Factory.create both the after_build and after_create callbacks get called.
Any help is much appreciated.
UPDATE:
So the User model I am using does a before_validation call to the method that checks if there is a beta invite. If I move this method call to before_save instead. It works correctly. Is there something i'm over looking. When does factory_girl run the after_build and after_create callbacks in relation to active-record's before_validation and before_save?
To me it seems like it just should be able to work, but I have had problems with associations in Factory-girl as well. An approach I like to use in a case like this, if the relations are less evident, is to define a special method, inside your factory as follows:
def Factory.create_beta_user
beta_invite = Factory(:beta_invite)
beta_user = Factory(:user, :email => beta_invite.email)
beta_user
end
and to use that in your tests, just write
Factory.create_beta_user
Hope this helps.
Not sure if this would help you but this is the code I used:
# Create factories with Factory Girl
FactoryGirl.define do
# Create a sequence of unique factory users
sequence(:email) { |n| "factoryusername+#{n}#example.com"}
factory :user do
email
password "factorypassword"
# Add factory user email to beta invite
after(:build) {|user| BetaInvite.create({:email => "#{user.email}"})}
end
end
I found this comment gave a really good example:
term = create(:term)
period = create(:period, term: term)
candidate = create(:candidate, term: term)
I applied it to my situation and can confirm it works.

Is validates_presence_of the preferred technique to require a has_many relationship

Basically: My model requires at least one instance of an associated model be present. Should I use validates_presence_of to assert this validation, or should I write some custom validation code?
Here are the essentials of my model:
class Event < ActiveRecord::Base
has_and_belongs_to_many :channels
validates_presence_of :channels, :message => "can't be empty"
end
(I assume things would be the same if I used has_many in place of has_and_belongs_to_many.)
Instead of the validates_presence_of line I could do this:
def validate
errors.add(:channels, "can't be empty") if channels.size < 1
end
I replaced the latter with the former in the Rails app I'm working on and am wondering if there might be any problems.
So to be more sure, I wrote the following rspec coverage, and both implementations respond the same:
describe Event do
before do
#net = Factory.create(:network)
#net_config = Factory.create(:network_config, :network => #net)
end
it "must have a channel" do
e = Factory.build(:event, :network => #net, :channels => [])
e.should have(1).error_on(:channels)
end
end
That is, if I remove the validation code, the above spec fails; if I put in either version of the validation code, the above spec passes.
So I might assume that my new implementation is ok. But I've read that validates_presence triggers a database load which, in turn, would wipe out any in-memory objects constructed from nested attributes. The proxy_target method, on the other hand, will return the in-memory objects without triggering a load. Some links on proxy_target: http://rubydoc.info/docs/rails/ActiveRecord/Associations/AssociationProxy http://withoutscope.com/2008/8/22/don-t-use-proxy_target-in-ar-association-extensions
In my particular case I'm not using ActiveRecord::Relation, but I wonder if I need to be cautious about this.

How do I test that my table design implements my associations properly?

I have written my basic models and defined their associations as well as the migrations to create the associated tables.
EDIT - Adding emphasis to what I specifically want to test.
I want to be able to test:
The associations are configured as intended
The table structures support the associations properly
I've written FG factories for all of my models in anticipation of having a complete set of test data but I can't grasp how to write a spec to test both belongs_to and has_many associations.
For example, given an Organization that has_many Users I want to be able to test that my sample Organization has a reference to my sample User.
Organization_Factory.rb:
Factory.define :boardofrec, :class => 'Organization' do |o|
o.name 'Board of Recreation'
o.address '115 Main Street'
o.city 'Smallville'
o.state 'New Jersey'
o.zip '01929'
end
Factory.define :boardofrec_with_users, :parent => :boardofrec do |o|
o.after_create do |org|
org.users = [Factory.create(:johnny, :organization => org)]
end
end
User_Factory.rb:
Factory.define :johnny, :class => 'User' do |u|
u.name 'Johnny B. Badd'
u.email 'jbadd#gmail.com'
u.password 'password'
u.org_admin true
u.site_admin false
u.association :organization, :factory => :boardofrec
end
Organization_spec.rb:
...
it "should have the user Johnny B. Badd" do
boardofrec_with_users = Factory.create(:boardofrec_with_users)
boardofrec_with_users.users.should include(Factory.create(:johnny))
end
...
This example fails because the Organization.users list and the comparison User :johnny are separate instances of the same Factory.
I realize this doesn't follow the BDD ideas behind what these plugins (FG, rspec) seemed to be geared for but seeing as this is my first rails application I'm uncomfortable moving forward without knowing that I've configured my associations and table structures properly.
Your user factory already creates an organization by virtue of the Factory Girl association method:
it "should associate a user with an organization" do
user = Factory.create(:johnny)
user.organization.name.should == 'Board of Recreation'
organization = user.organization
organization.users.count.should == 1
end
Take a look at 'log/test.log' after running your spec -- you should see an INSERT for both the organization and the user.
If you wanted to test this without the Factory Girl association, make a factory that just creates the user and make the association in the spec:
it "should associate a user with an organization" do
user = Factory.create(:johnny_no_org)
org = Factory.create(:boardofrec)
org.users.should be_empty
org.users << user
org.users.should include(user)
end
Of course all this is doing is testing whether ActiveRecord is doing its job. Since ActiveRecord is already thoroughly tested, you'll want to concentrate on testing the functionality of your application, once you've convinced yourself that the framework actually does what it's supposed to do.

Is it legal to stub the #class method of a Mock object when using RSpec in a Ruby on Rails application?

I would like to stub the #class method of a mock object:
describe Letter do
before(:each) do
#john = mock("John")
#john.stub!(:id).and_return(5)
#john.stub!(:class).and_return(Person) # is this ok?
#john.stub!(:name).and_return("John F.")
Person.stub!(:find).and_return(#john)
end
it.should "have a valid #to field" do
letter = Letter.create!(:to=>#john, :content => "Hello John")
letter.to_type.should == #john.class.name
letter.to_id.should == #john.id
end
[...]
end
On line 5 of this program, I stub the #class method, in order to allow things like #john.class.name. Is this the right way to go? Will there be any bad side effect?
Edit:
The Letter class looks like this:
class Letter < ActiveRecord::Base
belongs_to :to, :polymorphic => true
[...]
end
I wonder whether ActiveRecord gets the :to field's class name with to.class.name or by some other means. Maybe this is what the class_name method is ActiveRecord::Base is for?
I think you should be using mock_model for this particular case.
Your before(:each) would look like that:
before(:each) do
#john = mock_model(Person, :name => "John F.")
Person.stub!(:find).and_return(#john)
end
Then for your other question, you should not really care about how Rails works to test your behaviour. I don't think it's a good idea to test to_type and to_id fields yourself. This is Rails behaviour and as such should be tested in Rails, not in your project.
I have been using Remarkable for a while and it makes this really easy to specify:
describe Letter
should_belong_to :to, :polymorphic => true
end

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