Rspec: Creating user before testing method - ruby-on-rails

Question

Hi I am new to rspec (and unit testing in general) and want to test the following method:
class HelloController < ApplicationController
def hello_world
user = User.find(4)
#subscription = 10.00
render :text => "Done."
end
end
I am trying to use Rspec like so:
Describe HelloController, :type => :controller do
describe "get hello_world" do
it "should render the text 'done'" do
get :hello_world
expect(response.body).to include_text("Done.")
end
end
end
I would like to simply test that the method works properly and renders the test "done". I get the following error when I run the test:
Failure/Error: user = User.find(4)
ActiveRecord::RecordNotFound:
Couldn't find User with 'id'=4
But how do I properly create a user with that id before executing it? I have tried the following based on other tutorials and questions but it doesn't work:
describe "get hello_world" do
let(:user) {User.create(id: 4)}
it "should render the text 'done'" do
get :hello_world
expect(response.body).to include_text("Done.")
end
end
Thank you in advance.

Answer 1

Hey so really no action (e.g. def hello_world) should rely on a specific id. So a simple alternative could be to use user = User.last or to find the user by name user = User.find_by(name: "name"). Then in the test you would create any user if you using User.last in the action.
describe "get hello_world" do
let(:user) {User.create!}
it "should render the text 'done'" do
get :hello_world
expect(response.body).to include_text("Done.")
end
end
or if you are searching by name you can make a user with that name;
describe "get hello_world" do
let(:user) {User.create!(name: "name")}
it "should render the text 'done'" do
get :hello_world
expect(response.body).to include_text("Done.")
end
end
Hope this helps, questions welcome.

Answer 2

Do you really mean to use 'user = User.find(4)'? If you really meant to do that, you should stub the User's find method and return a user object.
it "should render the text 'done'" do
u = User.new #a new user, your test database is empty, so there's no user with id 4
User.stub(find: u) #stub the User's find method to return that new user
get :hello_world
expect(response.body).to include_text("Done.")
end
Another option is to send the user_id via params
it "should render the text 'done'" do
u = User.create(.... your user params)
get :hello_world, user_id: u.id
expect(response.body).to include_text("Done.")
end
and
def hello_world
user = User.find(params[:user_id])
#subscription = 10.00
render :text => "Done."
end
Anyway, I don't think you should be doing that, a hardcoded id is a bad sign. If you need to control users registrations and logins you can use something like Devise, and you may need to create an login a user before the spec.