CODEWITHSUNDEEP
ruby-on-railsrspecrefactoringtddbdd
Andrew
Andrew

Reputation: 43153

Rspec mocking for testing queries of an associated record

I have the following model:

class Kueue < ActiveRecord::Base
    attr_accessible :name, :user_id

    belongs_to :user
    has_and_belongs_to_many :photos

    scope :empty, includes(:photos).where{ photos.id.eq(nil) }
    scope :with_photos, includes(:photos).where{ photos.id.not_eq(nil) }
end

I want to write specs for the scopes, to make sure they're reliably working. My problem is how to deal with the Photo model. Photos have a lot of validations on them, for instance they must belong_to a User. So, I can write a working spec for these queries like so:

describe "queries" do
    before :each do
        @empty = Fabricate(:kueue)
        @full = Kueue.new :name => "Full Queue"
        @full.photos << Fabricate(:photo)
        @full.save
    end

    it "should find empty queues" do
        Kueue.empty.should_not include(@full)
    end

    it "should find queues with photos" do
        Kueue.with_photos.should_not include(@empty)
    end
end

However, as you can imagine this is sloooow. This makes a bunch of calls to the database. (1) to make two kueues, (2) to make a photo, (3) to make a user who owns the photo... and so on, down the line.

This seems like a simple enough problem, all I need is one join record between a photo and a kueue and I can test this really fast. So how would you go about mocking this interaction so you can test it faster and in better isolation?

PS: I'm using Rails 3.2.8, Squeel (hence the query syntax) and my model is called Kueue because Queue is a reserved word in Rails :)

Upvotes: 0

Views: 691

Answers (1)

phoet
phoet

Reputation: 18845

i think that it would not make sense to mock in the context of scopes.

scopes are basically database-queries and you want to make sure they work with, you know, the database.

so if your problem is test-performance, then i would suggest:

  • try out fixtures in this case

OR

  • skip model validation, to reduce the models needed

Upvotes: 2

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