How to share a variable with many "it" examples in rspec - ruby-on-rails

Question

I am using let to create a user record using factory girl. However i want to use exactly the same variable across 2 tests in the context as the user_id and email are important to the external API i am sending.
However i had no luck making a single variable for using across the examples. Here is my current code
context "User" do
let(:user) { FactoryGirl.create(:user) }
it "should create user and return 'nil'" do
expect(send_preferences(user, "new")).to eq nil
end
it "should not create user preferences again after sending two consecutive same requests" do
expect(send_preferences(user, "new")).to eq "User preferences already saved. No need to re-save them."
end
it "should update user preferences" do
expect(send_preferences(user, "update")).to eq nil
end
end
any clues?

Answer 1

You can use lets within lets:
context "User" do
let(:email_address) { 'test#test.com' }
let(:user) { FactoryGirl.create(:user, email_address: email_address) }
You will then also have access to the email_address variable within all your tests.
This works because previously the email address was being randomly generated by the factory every time the user was created, as we hadn't set a value for it anywhere. So, we called the code below in each test:
send_preferences(user, "new")
It called the 'user' let which created a new user with a completely random email address (as we hadn't give it a specific email value). Therefore during the backend API call it was sending a different email address every time.
let(:user) { FactoryGirl.create(:user) }
However, when we defined the email address 'let' as 'test#test.com', and passed that into the user factory as in the code I provided, we overrode the randomly generated email address with our own static value, So, every time we call the code again:
send_preferences(user, "new")
It now triggers the user factory create which is also taking our new 'email_address' let, which is always set to a specific value of test#test.com every time it is called.
let(:email_address) { 'test#test.com' }
let(:user) { FactoryGirl.create(:user, email_address: email_address) }
Therefore, when the backend API call is made the email address is always what we set it to.
Also, as it is a let we can use that variable in any of the tests themselves if we wish. For example:
it 'should set the email address' do
expect(user.email_address).to eq(email_address)
end
It's quite hard to explain in a few sentences but let me know if that's still not clear.

Answer 2

Having an instantiated variable shared among multiple tests is an anti-pattern 90% of the time in my opinion.
The problem with doing something like the below is you will be creating objects in your db without doing a cleanup.
before(:all) do
#user = FactoryGirl.create :user
end
Sure, you can do a before(:after) block or use DatabaseCleaner, but I think it is much better practice for tests to be as standalone as possible. In your case, make your setup of a send_preferences event before making an expectation on what happens the second time:
context "User" do
let(:user) { FactoryGirl.create(:user) }
# ...
it "should not create user preferences again after sending two consecutive same requests" do
send_preferences(user, "new") # Setup
expect(send_preferences(user, "new")).to eq "User preferences already saved. No need to re-save them."
end
it "should update user preferences" do
send_preferences(user, "new") # Setup
expect(send_preferences(user, "update")).to eq nil
end
end