Add tests for dependent :destroy in the Relationship model (Chapter 11, Exercise 1 Rails Tutorial, 2nd Ed)

Question

Pretty sure these tests are working correctly. Got them to fail by removing the dependent: :destroy options on the has_many :relationships and has_many :reverse_relationships in user.rb.

Wanted to share what I did in case anyone else is working through Michael Hartl's Rails Tutorial 2nd Edition, Chapter 11 Exercises.

A few questions arose from this exercise (see bottom of this post). If anyone could help, that'd be great.

Chapter 11, Exercise 1:

Add tests for dependent :destroy in the Relationship model (Listing 11.4 and Listing 11.16) by following the example in Listing 10.15.

Here's my test: spec/models/user_spec.rb

require 'spec_helper'

describe User do

  before do
  @user = User.new(name: "Example User", email: "[email protected]", 
                   password: "foobar", password_confirmation: "foobar")
  end

  subject { @user }

  [...code omitted...]

  describe "relationship associations" do
    let(:other_user) { FactoryGirl.create(:user) }
    before do
      @user.save
      @user.follow!(other_user)
      other_user.follow!(@user)
    end

    it "should destroy associated relationships" do
      relationships = @user.relationships
      @user.destroy
      relationships.should be_empty
    end

    it "should destroy associated reverse relationships" do
      reverse_relationships = @user.reverse_relationships
      @user.destroy
      reverse_relationships.should be_empty
    end
  end

---

A couple questions arose from this exercise:

Question 1:

My initial tests were relationships.should be_nil reverse_relationships.should be_nil

But, realized an array was still being returned, despite no user existing. So, when a user doesn't exist and an association method is called, the result is still an array? Is this always true?

Question 2:

I wanted to play around with deleting relationships and reverse_relationships for a user in the rails console.

I tried this

> user = User.first
> user.relationships
 # returns a bunch of relationships
> user.relationships.destroy
=> []
> user.relationships
 # returns same bunch of relationships

How do I actually destroy the relationships permanently? Seems like good thing to know when exploring in console.

Thanks! I'm still pretty new to Rails

Answer 1

I'm a ruby/rails noob too.

Question 1: Searched rubyonrails.org for has_many and it says

Returns an array of all the associated objects. An empty array is returned if none are found.

On a side note, you can test for both nil and empty:

relationships.present?.should be_false

Question 2: The user.relationships.destroy requires an :id

user.relationships.destroy '1'