Testing an expected order of an array in RSpec / Rails - ruby-on-rails

Question

In a RSpec spec file I have the following test
it 'should return 5 players with ratings closest to the current_users rating' do
matched_players = User.find(:all,
:select => ["*,(abs(rating - current_user.rating)) as player_rating"],
:order => "player_rating",
:limit => 5)
# test that matched_players array returns what it is suppose to
end
How would I complete this to test that matched_players is returning the correct users.

Answer 1

I think you should first introduce some test users to the test DB (using for example a Factory) and afterwards see that the test is returning the correct ones.
Also it would make more sense to have a method in your model that would return the matched users.
For example:
describe "Player matching" do
before(:each) do
#user1 = FactoryGirl.create(:user, :rating => 5)
...
#user7 = FactoryGirl.create(:user, :rating => 3)
end
it 'should return 5 players with ratings closest to the current_users rating' do
matched_players = User.matched_players
matched_players.should eql [#user1,#user3,#user4,#user5,#user6]
end
end

Answer 2

Your model shouldn't know about your current user (the controllers know about this concept)
You need to extract this as a method on the User class otherwise there's no point in testing it, i.e. why test logic that isn't even in your app code?
The function that gets the matched players doesn't need to know about the current user, or any user for that matter, just the rating.
To test it, create a bunch of User instances, call the method, and see that the result is a list of the correct user instances you expect.
models/user.rb
class User < ActiveRecord::Base
...
def self.matched_players(current_user_rating)
find(:all,
select: ["*,(abs(rating - #{current_user_rating)) as match_strength"],
order: "match_strength",
limit: 5)
end
...
end
spec/models/user_spec.rb
describe User do
...
describe "::matched_players" do
context "when there are at least 5 users" do
before do
10.times.each do |n|
instance_variable_set "#user#{n}", User.create(rating: n)
end
end
it "returns 5 users whose ratings are closest to the given rating, ordered by closeness" do
matched_players = described_class.matched_players(4.2)
matched_players.should == [#user4, #user5, #user3, #user6, #user2]
end
context "when multiple players have ratings close to the given rating and are equidistant" do
# we don't care how 'ties' are broken
it "returns 5 users whose ratings are closest to the given rating, ordered by closeness" do
matched_players = described_class.matched_players(4)
matched_players[0].should == #user4
matched_players[1,2].should =~ [#user5, #user3]
matched_players[3,4].should =~ [#user6, #user2]
end
end
end
context "when there are fewer than 5 players in total" do
...
end
...
end
...
end