Rails 3 RSpec and assert_select

Question

I've thought to try to use Rspec. But I get a next problem with the assert_select.

1) UserController login page open login page contains all expected controls
Failure/Error: assert_select "form[action=?]", "/user/login" do MiniTest::Assertion:
Expected at least 1 element matching "form[action='/user/login']", found 0.
# (eval):2:in `assert'
# ./spec/controllers/user_controller_spec.rb:20:in `block (3 levels) in <top (required)>'

This is my code snippet

describe UserController do
  describe "login page open" do
    it "login page contains all expected controls" do
      get :login
      assert_select "form[action=?]", "/user/login" do
      assert_select "input[name=?]", "username"
      assert_select "input[name=?]", "password"
      assert_select "input[type=?]", "submit"
    end
  end
end

When I open a login page in a browser this page opens without problem.

Answer 1

By default, RSpec (at least in newer versions) prevents Rails from rendering views when you run controller specs specs. They want you to test your views in view specs, not controller specs. Since the views don't render, assert_select always fails.

But for people who (like me) want to test the occasional snippet of a view in their controller specs, they provide a render_views method. You have to call it in your describe or context block, though, not inside the it block.

describe UserController do

  render_views       # <== ADD THIS

  describe "login page open" do
    it "login page contains all expected controls" do
      get :login
      assert_select "form[action=?]", "/user/login" do
      assert_select "input[name=?]", "username"
      assert_select "input[name=?]", "password"
      assert_select "input[type=?]", "submit"
    end
  end
end

Answer 2

Controller tests are for testing controllers.

assert_select matches something that is in your view code.

It is a good idea keep your controllers separated from your views, and this includes tests done on controllers and on views. You should use assert_select in your views test (the ones that are usually on spec/views), not on your controller tests.