```ruby
require 'rails_helper'

RSpec.describe PortfoliosController, type: :controller do
  render_views

  it "shows a loading screen when there is no data for the requested user" do
    github_username = 'unseen_user'
    get :show, id: github_username
    expect(response.body).to match /wait|load|fetch|get/i
    expect(response.body).to include github_username
  end

  it "shows the user's name if the data is available" do
    portfolio = Portfolio.new(user: User.new(name: 'Edward Anderson', login: 'nilbus'))
    PortfolioStore.new.save(portfolio)
    get :show, id: 'nilbus'
    expect(response.body).to include portfolio.user.name
  end
end
```

Use fixture data for the controller test
user
```ruby
require 'rails_helper'

RSpec.describe PortfoliosController, type: :controller do
  render_views

  it "shows a loading screen when there is no data for the requested user" do
    github_username = 'unseen_user'
    get :show, id: github_username
    expect(response.body).to match /wait|load|fetch|get/i
    expect(response.body).to include github_username
  end

  it "shows the user's name if the data is available" do
    get :show, id: 'test'
    expect(response.body).to include 'test'
  end
end
```
assistant