Is there a way to test whether a template has properties in an RSpec controller test?

Question

So I'm working on my first Rails project and am working on getting some automated testing set up. Right now, I have a template for a form which has a select tag, which is getting its information dynamically based on a mocked API response. As of now, my template successfully renders, but I would like to be able to access that select tag and see if its child options match with the my mock API response. Haven't been able to find a whole lot in the docs about this particular use case, hoping someone here may be able to point me in the right direction. Here's essentially what I have so far:

RSpec.describe MyController, type: :controller, do
  describe "GET my_thing/index" do
    it "renders the index template" do
      stub_request(:get, "https://outsideapi.net/endpoint").
        to_return(status: 200,
                  body: {
                    "values" => [
                      { "name": "foo", "id": "10000" },
                      { "name": "bar", "id": "10001" },
                      { "name": "baz", "id": "10002" },
                     ],
                  }.to_json,
                  headers: {})

      get :index, params: { request_identifier: generate_request_identifier() }
      expect(response).to have_http_status(:success)
      expect(response).to render_template(:index)
      # Some code that will hopefully get elements off the template
    end
  end

score 0 · Accepted Answer · answered Mar 17 '21 at 07:06

According to Rspec docs for controller tests:

by default, views are not rendered. See views are stubbed by default and render_views for details.

So first things first, you'll want to instruct Rspec to render your controller views by adding a render_views directive in your test suite as mentioned here:

require "rails_helper"

RSpec.describe WidgetsController, :type => :controller do
  render_views # <-- This

  describe "GET index" do
    it "has a widgets related heading" do
      get :index
      expect(response.body).to match /<h1>.*widgets/im
    end
  end
end

Finally, you'll be able to match the JSON array with the rendered HTML using somthing like this(code is untested, but it should hopefully drive the point):


RSpec.describe MyController, type: :controller, do
  describe "GET my_thing/index" do
    it "renders the index template" do
      # Can also be added below the `describe` call if view rendering is needed elsewhere.
      render_views
      select_values = [
                      { "name": "foo", "id": "10000" },
                      { "name": "bar", "id": "10001" },
                      { "name": "baz", "id": "10002" },
                     ]
      stub_request(:get, "https://outsideapi.net/endpoint").
        to_return(status: 200,
                  body: {
                    "values" => select_values,
                  }.to_json,
                  headers: {})

      get :index, params: { request_identifier: generate_request_identifier() }
      expect(response).to have_http_status(:success)
      expect(response).to render_template(:index)
      # Extract the select value names as an array of strings.
      select_value_names = select_values.map {|v| v['name']}
      expect(response.body).to include(select_value_names)
    end
  end

On a related note, if you're running tests against page contents, you might want to consider using acceptance testing frameworks such as Capybara, which integrates well with Rspec.

Thanks Abdulaziz! That makes perfect sense, I thought `render_views` were just toggled in the RSpec config. And I ended up going the Capybara route after playing with this for an hour or so, was exactly what I needed. — jcksnparsons, Mar 17 '21 at 14:15

Is there a way to test whether a template has properties in an RSpec controller test?

1 Answers1