test 'where' clause using rspec - sql

Question

i have been learning to using rspec.
i have to test this one:
Book.where(old:false, id:user.collections.select(:book_id).group(:book_id).map(&:book_id)).map{|b|[b.name, b.id] }
what i've already done is :
#user = Fabricate(:user)
#book1 = Fabricate(:book, old:false)
#book2 = Fabricate(:book, old:true)
#collection = Fabricate(:collection, book_id:#book1.id)
#collection2 = Fabricate(:collection, book_id:#book2.id)
#user.collections << #book1 << #book2
#books = Book.where(old:false, id:#user.collections.select(:book_id).group(:book_id).map(&:book_id)).map{|b|[b.name, b.id]}
.....
it "books" do
subject[:filter].should == #books.map{|d| [d.name, d.id]}
end
it expected a book, but i got 0. did i forget something?
thanks in advance for any idea and help!

Answer 1

Your code is very unreadable and hard to test. You should split the execution into smaller methods.
Book.where(old:false, id:user.collections.select(:book_id).group(:book_id).map(&:book_id)).map{|b|[b.name, b.id] }
could be
class Book
def self.find_books_with_name(ids)
where(old: false, id: ids).map { |b| [b.name, b.id] }
end
end
Then you can call it with:
Book.find_books_and_name(user.collections.select(:book_id).group(:book_id).map(&:book_id))
which appears equally insane to me. Add to your user model and collection model something like
class Collection
def self.book_ids
select(:book_id).group(:book_id).map(&:book_id)
end
end
Now you have
Book.find_books_and_name(user.collections.book_ids)
and now you can (and you should) test each method separately. A failure will be easier to spot and the test itself will be much more simple, without all that coupling to various models and records.