test: Add system tests for exercise administration

The exercise administration form is a critical pass. The test
will secure the functionality with the upcoming changes.

Relates to #2922

Author: arkirchner

spec/support/wait_for_turbolinks.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+module WaitForTurbolinks
+  # Capybara waits ordinary page navigation. With Turbolinks
+  # the page is checked immediate. This might be before the
+  # Turbolinks navigation finished. This makes system tests brittle.
+  # By checking the Turbolinks progress bar we can wait for the
+  # Turbolinks request to finish.
+  def wait_for_turbolinks
+    has_css?('.turbolinks-progress-bar', visible: true)
+    has_no_css?('.turbolinks-progress-bar')
+    nil
+  end
+end
+
+RSpec.configure do |config|
+  config.include WaitForTurbolinks, type: :system
+end

spec/system/exercises_system_spec.rb

@@ -0,0 +1,163 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe 'Exercise creation', :js do
+  let!(:ruby) { create(:ruby) }
+
+  before do
+    visit(sign_in_path)
+    fill_in('email', with: teacher.email)
+    fill_in('password', with: attributes_for(:teacher)[:password])
+    click_button(I18n.t('sessions.new.link'))
+    wait_for_turbolinks
+  end
+
+  context 'when an exercise created' do
+    let(:teacher) { create(:teacher) }
+    let(:submission_deadline) { 3.months.from_now.beginning_of_minute }
+    let(:late_submission_deadline) { submission_deadline + 1.week }
+    let(:title) { 'Ruby challenge' }
+    let(:internal_title) { 'Project Ruby: Table flip' }
+
+    let(:code) do
+      <<~RUBY
+        def self.❨╯°□°❩╯︵┻━┻
+          puts "Calm down, bro"
+        end
+      RUBY
+    end
+
+    let(:description) do
+      <<~TEXT
+        Ruby challenge
+
+        Do something with Ruby.
+      TEXT
+    end
+
+    before do
+      visit(exercises_path)
+      click_on I18n.t('shared.new_model', model: Exercise.model_name.human)
+      wait_for_turbolinks
+    end
+
+    it 'creates an exercise with nested data' do
+      fill_in Exercise.human_attribute_name(:title), with: title
+      fill_in Exercise.human_attribute_name(:internal_title), with: internal_title
+
+      # description
+      within('.markdown-editor__wrapper') do
+        find('.ProseMirror').set(description)
+      end
+
+      chosen_select(Exercise.human_attribute_name(:execution_environment), ruby.name)
+
+      chosen_date_time_select(Exercise.human_attribute_name(:submission_deadline), submission_deadline)
+
+      chosen_date_time_select(Exercise.human_attribute_name(:late_submission_deadline), late_submission_deadline)
+
+      check Exercise.human_attribute_name(:public)
+
+      click_on I18n.t('exercises.form.add_file')
+
+      within(find_by_id('files').all('li').last) do
+        fill_in CodeOcean::File.human_attribute_name(:name), with: 'main'
+
+        chosen_select(CodeOcean::File.human_attribute_name(:file_type), ruby.file_type.name)
+        chosen_select(CodeOcean::File.human_attribute_name(:role), I18n.t('code_ocean/files.roles.main_file'))
+
+        check(CodeOcean::File.human_attribute_name(:read_only))
+
+        find_by_id('editor-edit').click
+        send_keys code.strip
+      end
+
+      click_button I18n.t('shared.create', model: Exercise.model_name.human)
+
+      expect(page).to have_text 'Exercise has successfully been created.'
+
+      # Exercise is created with expected attributes
+      expect(page).to have_text(title)
+      expect(page).to have_text(internal_title)
+      expect(page).to have_text(submission_deadline.to_s)
+      expect(page).to have_text(late_submission_deadline.to_s)
+      expect(page).to have_text(ruby.name)
+
+      description.lines.each do |line|
+        expect(page).to have_text(line.delete("\n"))
+      end
+
+      # Exercise includes the code
+      find('span', text: 'main.rb').click
+
+      code.lines.each do |code_line|
+        expect(page).to have_text(code_line.delete("\n"))
+      end
+    end
+  end
+
+  context 'when an exercise is updated' do
+    let!(:exercise) { create(:fibonacci) }
+    let(:teacher) { exercise.user }
+    let(:deleted_file_name) { 'reference.rb' }
+    let(:updated_file_name) { 'exercise.rb' }
+
+    before do
+      visit(exercises_path)
+    end
+
+    it 'updates an exercise with nested data' do
+      click_on exercise.title
+      click_on 'Edit'
+      click_on I18n.t('shared.edit')
+
+      fill_in Exercise.human_attribute_name(:difficulty), with: 5
+
+      find('span', text: updated_file_name).click
+
+      within('.card', text: updated_file_name) do
+        fill_in CodeOcean::File.human_attribute_name(:name), with: 'main_exercise'
+      end
+
+      find('span', text: deleted_file_name).click
+
+      within('.card', text: deleted_file_name) do
+        accept_confirm do
+          find('div.btn', text: I18n.t('shared.destroy')).click
+        end
+      end
+
+      click_button I18n.t('shared.update', model: Exercise.model_name.human)
+
+      expect(page).to have_text("#{Exercise.human_attribute_name(:difficulty)}\n5")
+      expect(page).to have_text('main_exercise.rb')
+      expect(page).to have_no_text(deleted_file_name)
+    end
+  end
+
+  def chosen_select(name, value)
+    id = first('label', text: name)[:for]
+
+    set_value_for_chosen_element(id, value)
+  end
+
+  def chosen_date_time_select(name, date)
+    id = first('label', text: name)[:for]
+
+    set_value_for_chosen_element("#{id}_1i", date.year.to_s)
+    set_value_for_chosen_element("#{id}_2i", date.strftime('%B'))
+    set_value_for_chosen_element("#{id}_3i", date.day.to_s)
+    set_value_for_chosen_element("#{id}_4i", date.hour.to_s)
+    set_value_for_chosen_element("#{id}_5i", date.min.to_s)
+  end
+
+  def set_value_for_chosen_element(id, value)
+    element = find_by_id("#{id}_chosen")
+    element.click
+
+    within(element) do
+      first('.chosen-results li', text: value).click
+    end
+  end
+end