如何为通过 Rubocop 标准的 Rails 视图编写 RSpec？

Question

I used rails generate scaffold to generate my controller, model, views, etc. as well as their associated rspecs. The rspec generated for the views all have a common problem. The generated rspec is:

require 'rails_helper'

RSpec.describe 'import_files/new', type: :view do
  before do
    assign(:import_file, build(:import_file))
  end

  it 'renders new import_file form' do
    render

    assert_select 'form[action=?][method=?]', import_files_path, 'post' do
      assert_select 'input[name=?]', 'import_file[path]'
      assert_select 'select[name=?]', 'import_file[file_type]'
    end
  end
end

Rubocop is complaining that there is no expectation within the example (with the error at the line with it ). The assert_select from what I can tell does an expectation as well as other things so I tried adding this to my .rubocop.yml file:

RSpec:
  Language:
    Expectations:
      - assert_select

but now Rubocop complains that the example has three expectations instead of just one. Curiously, in the RSpec Style Guide example of a view spec , they have the same basic structure of an expect selecting out a piece of the DOM and passing it down to an inner expect -- AND, Rubocop flags it as having too many expectations.

Perhaps RSpec/MultipleExpectations in views should just always be disabled?

Edit (and a somewhat different question):

After the render what can I use to select out just the form and it's children without adding in any expectations?

I'm thinking (roughly sketching and not knowing what I'm doing) something like:

RSpec.describe 'import_files/new', type: :view do
  before do
    assign(:import_file, build(:import_file))
  end

  it 'renders new import_file form' do
    render

    expect(rendered).to have_selector('form', method: :post, action: import_files_path)
  end

  it 'renders new import_file form witn path field' do
    render

    select_out_just_the_form do
      assert_select 'input[name=?]', 'import_file[path]'
    end
  end

  it 'renders new import_file form with file_type field' do
    render

    select_out_just_the_form do
      assert_select 'select[name=?]', 'import_file[file_type]'
    end
  end
end

Two questions now:

1. what can I use for the select_out_just_the_form ?
2. Could I / should I rearrange this so the render happens just once something like this:

RSpec.describe 'import_files/new', type: :view do
  before do
    assign(:import_file, build(:import_file))
  end

  begin
    render

    it 'renders new import_file form' do
      expect(rendered).to have_selector('form', method: :post, action: import_files_path)
    end

    select_out_just_the_form do
      it 'renders new import_file form witn path field' do
        assert_select 'input[name=?]', 'import_file[path]'
      end

      it 'renders new import_file form with file_type field' do
        assert_select 'select[name=?]', 'import_file[file_type]'
      end
    end
  end
end

The reason the 2nd style might be bad is if the outer form fails, there are going to be 3 errors where actually the inner 2 errors are a simple consequence of the outer error of not rendering the form. I remember when a simple omitted semicolon could generate loads of errors which only created a big mess.

Answer 1

This is what I came up with.

require 'rails_helper'

RSpec.describe 'import_files/new', type: :view do
  let(:form_css) { "form[action='#{import_files_path}'][method=post]" }

  before do
    assign(:import_file, build(:import_file))
    render
  end

  it 'renders new import_file form' do
    assert_select form_css
  end

  describe 'the rendered form' do
    let(:form) do
      css_select form_css
    end

    it 'has a path field' do
      assert_select form, 'input[name=?]', 'import_file[path]'
    end

    it 'has a file_type field' do
      assert_select form, 'select[name=?]', 'import_file[file_type]'
    end
  end
end

Execution results:

import_files/new
  renders new import_file form
  the rendered form
    has a path field
    has a file_type field

Finished in 0.25221 seconds (files took 1.35 seconds to load)
3 examples, 0 failures

I also added this to my.rubocop.yml (as previously stated):

RSpec:
  Language:
    Expectations:
      - assert_select