Failing Rspec tests with Redis and Rails

Question

I've refactored my Rails code to store user relationships in Redis instead of a Postgres database.

The code before:

# user.rb

has_many :relationships, foreign_key: "follower_id", dependent: :destroy
has_many :following, through: :relationships, source: :followed

def follow!(other_user)
  relationships.create!(followed_id: other_user.id)
end

The refactored code:

# user.rb

def follow!(other_user)
  rdb.redis.multi do
    rdb[:following].sadd(other_user.id)
    rdb.redis.sadd(other_user.rdb[:followers], self.id)
  end
end

def following
  User.where(id: rdb[:following].smembers)
end

The refactored code works but my existing specs are failing now:

describe "following a user", js: true do
  let(:other_user) { FactoryGirl.create(:user) }
  before { visit user_path(other_user) }

  it "should increment the following user count" do
    expect do
      click_button "Follow"
      page.find('.btn.following')
    end.to change(user.following, :count).by(1)
  end
end

Which now results in:

Failure/Error: expect do
   count should have been changed by 1, but was changed by 0

Rspec uses a different Redis database which gets flushed before each spec runs. As far as I can tell the spec should still be passing. Am I missing something here?

Answer 1

to change(user.followers, :count).by(1)

应该改为

to change(other_user.followers, :count).by(1)

Answer 2

Could this be a reload problem? Try this:

it "should increment the following user count" do
  expect do
    click_button "Follow"

    # user object is now stale, reload it from the DB
    user.reload
  end.to change(user.following, :count).by(1)
end