I haven't been able to find anything for a situation like this. I have a model which has a named scope defined thusly:
class Customer < ActiveRecord::Base
# ...
named_scope :active_customers, :conditions => { :active => true }
end
and I'm trying to stub it out in my Controller spec:
# spec/customers_controller_spec.rb
describe CustomersController do
before(:each) do
Customer.stub_chain(:active_customers).and_return(#customers = mock([Customer]))
end
it "should retrieve a list of all customers" do
get :index
response.should be_success
Customer.should_receive(:active_customers).and_return(#customers)
end
end
This is not working and is failing, saying that Customer expects active_customers but received it 0 times. In my actual controller for the Index action I have #customers = Customer.active_customers. What am I missing to get this to work? Sadly, I'm finding that it's easier to just write the code than it is to think of a test/spec and write that since I know what the spec is describing, just not how to tell RSpec what I want to do.
I think there's some confusion when it comes to stubs and message expectations. Message expectations are basically stubs, where you can set the desired canned response, but they also test for the call to be made by the code being tested. In contrast stubs are just canned responses to the method calls. But don't mix a stub with a message expectation on the same method and test or bad things will happen...
Back to your question, there are two things (or more?) that require spec'ing here:
That the CustomersController calls Customer#active_customers when you do a get on index. Doesn't really matter what Customer#active_customers returns in this spec.
That the active_customers named_scope does in fact return customers where the active field is true.
I think that you are trying to do number 1. If so, remove the whole stub and simply set the message expectation in your test:
describe CustomersController do
it "should be successful and call Customer#active_customers" do
Customer.should_receive(:active_customers)
get :index
response.should be_success
end
end
In the above spec you are not testing what it returns. That's OK since that is the intent of the spec (although your spec is too close to implementation as opposed to behavior, but that's a different topic). If you want the call to active_customers to return something in particular, go ahead and add .and_returns(#whatever) to that message expectation. The other part of the story is to test that active_customers works as expected (ie: a model spec that makes the actual call to the DB).
You should have the array around the mock if you want to test that you receive back an array of Customer records like so:
Customer.stub_chain(:active_customers).and_return(#customers = [mock(Customer)])
stub_chain has worked the best for me.
I have a controller calling
ExerciseLog.this_user(current_user).past.all
And I'm able to stub that like this
ExerciseLog.stub_chain(:this_user,:past).and_return(#exercise_logs = [mock(ExerciseLog),mock(ExerciseLog)])
Related
If I have a User model that includes a method dangerous_action and somewhere I have code that calls the method on a specific subset of users in the database like this:
class UserDanger
def perform_dangerous_action
User.where.not(name: "Fred").each(&:dangerous_action)
end
end
how do I test with RSpec whether it's calling that method on the correct users, without actually calling the method?
I've tried this:
it "does the dangerous thing, but not on Fred" do
allow_any_instance_of(User).to receive(:dangerous_action).and_return(nil)
u1 = FactoryBot.create(:user, name: "Jill")
u2 = FactoryBot.create(:user, name: "Fred")
UserDanger.perform_dangerous_action
expect(u1).to have_recieved(:dangerous_action)
expect(u2).not_to have_recieved(:dangerous_action)
end
but, of course, the error is that the User object doesn't respond to has_recieved? because it's not a double because it's an object pulled from the database.
I think I could make this work by monkey-patching the dangerous_action method and making it write to a global variable, then check the value of the global variable at the end of the test, but I think that would be a really ugly way to do it. Is there any better way?
I realised that I'm really trying to test two aspects of the perform_dangerous_action method. The first is the scoping of the database fetch, and the second is that it calls the correct method on the User objects that come up.
For testing the scoping of the DB fetch, I should really just make a scope in the User class:
scope :not_fred, -> { where.not(name: "Fred") }
which can be easily tested with a separate test.
Then the perform_dangerous_action method becomes
def perform_dangerous_action
User.not_fred.each(&:dangerous_action)
end
and the test to check it calls the right method for not_fred users is
it "does the dangerous thing" do
user_double = instance_double(User)
expect(user_double).to receive(:dangerous_action)
allow(User).to receive(:not_fred).and_return([user_double])
UserDanger.perform_dangerous_action
end
i think, in many cases, you don't want to separate a where or where.not into a scope, in that cases, you could stub ActiveRecord::Relation itself, such as:
# default call_original for all normal `where`
allow_any_instance_of(ActiveRecord::Relation)
.to receive(:where).and_call_original
# stub special `where`
allow_any_instance_of(ActiveRecord::Relation)
.to receive(:where).with(name: "...")
.and_return(user_double)
in your case, where.not is actually call ActiveRecord::QueryMethods::WhereChain#not method so i could do
allow_any_instance_of(ActiveRecord::QueryMethods::WhereChain)
.to receive(:not).with(name: "Fred")
.and_return(user_double)
I am trying to write two RSpec tests for two different problems that are much more advanced that what I'm used to writing.
What I'm trying to test within my controller:
def index
#buildings ||= building_class.active.where(place: current_place)
end
My attempt at writing the RSpec test:
describe 'GET :index' do
it "assigns #buildings" do
#buildings ||= building_class.active.where(place: current_place)
get :index
expect(assigns(:buildings)).to eq([building])
end
end
This test failed and wouldn't even run so I know I'm missing something.
My second test is needing to test the returned value of a class method. Here is what I am needing to test within the controller:
def class_name
ABC::Accountant::Business
end
Here is my attempt at testing this method:
describe "class name returns ABC::Accountant::Business" do
subject do
expect(subject.class_name).to eq(ABC::Accountant::Business)
end
end
For the first test I would do something like this:
First, I would move that .active.where(place: current_place) to a scope (I'm guessing building_class returns Building or something like that):
class Building << ApplicationRecord
scope :active_in, -> (place) { active.where(place: place)
Then it's easier to stub for the test
describe 'GET :index' do
it "assigns #buildings" do
scoped_buildings = double(:buildings)
expect(Building).to receive(:active_in).and_return(scoped_buildings)
get :index
expect(assigns(:buildings)).to eq(scoped_buildings)
end
end
Then your controller will do
#buildings ||= building_class.active_in(current_place)
This way you are testing two things: that the controller actually calls the scope and that the controller assigns the returned value on the #buildings variable (you don't really need to test the actual buidlings, you can test the scope on the model spec).
Personally, I feel like it would be better to do something like #buildings = current_place.active_buildings using the same idea of the scope to test that you are getting the active buildings of the current place.
EDIT: if you can't modify your controller, then the stubbing is a little different and it implies some chaining of methods that I don't like to explicitly test.
scoped_buildings = double(:buildings)
controller.stub_chain(:building_class, :active, :where).and_return(scoped_building)
get :index
expect(assings(:buildings)).to eq scoped_buildings
Note that now your test depends on a specific implementation and testing implementation is a bad practice, one should test behaviour and not implementation.
For the second, I guess something like this should work:
describe ".class_name" do
it "returns ABC::Accountant::Business" do
expect(controller.class_name).to eq(ABC::Accountant::Business)
end
end
IMHO, that the method's name if confusing, class_name gives the idea that it returns a string, you are not returnin a name, you are returning a class. Maybe you can change that method to resource_class or something less confusing.
How could I write a test to find the last created record?
This is the code I want to test:
Post.order(created_at: :desc).first
I'm also using factorybot
If you've called your method 'last_post':
def self.last_post
Post.order(created_at: :desc).first
end
Then in your test:
it 'should return the last post' do
expect(Post.last_post).to eq(Post.last)
end
On another note, the easiest way to write your code is simply
Post.last
And you shouldn't really be testing the outcome of ruby methods (you should be making sure the correct ruby methods are called), so if you did:
def self.last_post
Post.last
end
Then your test might be:
it 'should send the last method to the post class' do
expect(Post).to receive(:last)
Post.last_post
end
You're not testing the outcome of the 'last' method call - just that it gets called.
The accepted answer is incorrect. Simply doing Post.last will order the posts by the ID, not by when they were created.
https://apidock.com/rails/ActiveRecord/FinderMethods/last
If you're using sequential IDs (and ideally you shouldn't be) then obviously this will work, but if not then you'll need to specify the column to sort by. So either:
def self.last_post
order(created_at: :desc).first
end
or:
def self.last_post
order(:created_at).last
end
Personally I'd look to do this as a scope rather than a dedicated method.
scope :last_created -> { order(:created_at).last }
This allows you to create some nice chains with other scopes, such as if you had one to find all posts by a particular user/account, you could then chain this pretty cleanly:
Post.for_user(user).last_created
Sure you can chain methods as well, but if you're dealing with Query interface methods I feel scopes just make more sense, and tend to be cleaner.
If you wanted to test that it returns the correct record, in your test you could do something like:
let!(:last_created_post) { factory_to_create_post }
. . .
it "returns the correct post"
expect(Post.last_post).to eq(last_created_post)
end
If you wanted to have an even better test, you could create a couple records before the last record to verify the method under test is pulling the correct result and not just a result from a singular record.
How can you test the presence of a callback in your model, specifically one that's triggered by creating a record, such as after_create or after_commit on: :create?
Here's an example callback with the (empty) method that it calls.
# app/models/inbound_email.rb
class InboundEmail < ActiveRecord::Base
after_commit :notify_if_spam, on: :create
def notify_if_spam; end
end
Here's the pending spec, using RSpec 3.
# spec/models/inbound_email_spec.rb
describe InboundEmail do
describe "#notify_if_spam" do
it "is called after new record is created"
end
end
Using a message expectation to test that the method is called seems like the way to go.
For example:
expect(FactoryGirl.create(:inbound_email)).to receive(:notify_if_spam)
But that doesn't work. Another way is to test that when a record is created, something inside the called method happens (e.g. email sent, message logged). That implies that the method did get called and therefore the callback is present. However, I find that a sloppy solution since you're really testing something else (e.g. email sent, message logged) so I'm not looking for solutions like that.
I think Frederick Cheung is right. This should work. The problem with your example is that the callback has already been called before the expectation has been set.
describe InboundEmail do
describe "#notify_if_spam" do
it "is called after new record is created" do
ie = FactoryGirl.build(:inbound_email)
expect(ie).to receive(:notify_if_spam)
ie.save!
end
end
end
Having been inspired by Sandi Metz's approach to writing tests (http://www.confreaks.com/videos/2452-railsconf2013-the-magic-tricks-of-testing), I am trying to refactor a test for a Rails controller to assert that it is sending a command message properly.
Here are the relevant parts of the Application:
class DealsController < ApplicationController
def index
if params[:reset]
deal_filter.reset
...
class ApplicationController
def deal_filter
...
#deal_filter ||= DealFilter.new(args)
end
...
class DealFilter
def reset
...do work...
end
...
And here is the rspec test:
describe DealsController do
it "should send 'reset' to the deal_filter" do
df = instance_double("DealFilter")
get :index, reset: "true"
expect(df).to receive(:reset)
end
end
The test results that keep coming back are:
1) DealsController GET index for any user params contain 'reset' should send 'reset' to the deal_filter
Failure/Error: expect(df).to receive(:reset)
(Double "DealFilter (instance)").reset(any args)
expected: 1 time with any arguments
received: 0 times with any arguments
I have already confirmed that the reset param is being sent through the test and that the controller is following the appropriate path, yet the test continues to fail.
Can anyone suggest a possible reason for the failure or resources for further study? I am relatively new to object oriented thinking and using mocks with Rspec. Could it be that I have misunderstood the role of doubles?
Thanks for your time!
You need to make sure your double gets used. I think the best way to do that here is to stub the deal_filter method to return the double.
I addition I would isolate the expection, so that it's the only thing in the it block. This will make it easier to add more expections without duplication the setup logic.
describe DealsController do
let(:df) { instance_double("DealFilter") }
before do
allow(controller).to receive(:deal_filter).and_return(df)
get :index, reset: "true"
end
it "should send 'reset' to the deal_filter" do
expect(df).to have_received(:reset)
end
end
I think you're expecting your instance_double to be used automatically somewhere within the index action. That's not how doubles work. You can create a double and use it for things, but your code in the controller doesn't (and shouldn't) know anything about that double and so won't ever call anything on it.
For an example of how an instance double can actually be used see this documentation.
Another issue with your expectation is that you're not setting it early enough. When you expect an object to receive a method call there needs to be something that happens after that which would invoke that method. In your example the expectation to receive :reset is the very last line of your example.
I'd recommend reading up on how other people have tested controllers with rspec as a good starting place.