WIP: deleting drafts journey

app/controllers/forms/delete_confirmation_controller.rb

@@ -22,14 +22,25 @@ def destroy
         return redirect_to @back_url
       end
 
-      success_url = current_form.group.present? ? group_path(current_form.group) : root_path
+      if current_form.draft?
+        success_url = current_form.group.present? ? group_path(current_form.group) : root_path
 
-      unless FormRepository.destroy(current_form)
-        flash[:message] = "Deletion unsuccessful"
-        return redirect_to @back_url
-      end
+        unless FormRepository.destroy(current_form)
+          flash[:message] = "Deletion unsuccessful"
+          return redirect_to @back_url
+        end
+
+        redirect_to success_url, status: :see_other, success: t(".success", form_name: current_form.name)
+      elsif current_form.live_with_draft?
+        success_url = live_form_path(current_form.id)
 
-      redirect_to success_url, status: :see_other, success: t(".success", form_name: current_form.name)
+        unless RevertDraftFormService.new(current_form).revert_draft_to_live
+          flash[:message] = "Deletion unsuccessful"
+          return redirect_to @back_url
+        end
+
+        redirect_to success_url, status: :see_other, success: t(".success", form_name: current_form.name)
+      end
     end
 
   private

app/services/revert_draft_form_service.rb

@@ -0,0 +1,124 @@
+# This service reverts a draft form to its last live version,
+# effectively discarding all draft changes.
+class RevertDraftFormService
+  attr_reader :form
+
+  # A list of attributes on the Form model that should be reverted
+  FORM_ATTRIBUTES_TO_REVERT = %w[
+    available_languages
+    declaration_section_completed
+    declaration_text
+    external_id
+    form_slug
+    language
+    name
+    payment_url
+    privacy_policy_url
+    question_section_completed
+    s3_bucket_aws_account_id
+    s3_bucket_name
+    s3_bucket_region
+    share_preview_completed
+    submission_email
+    submission_type
+    support_email
+    support_phone
+    support_url
+    support_url_text
+    what_happens_next_markdown
+  ].freeze
+
+  def initialize(form)
+    @form = form
+  end
+
+  # Discards draft changes by reverting the form and its associations
+  # to the state of the last live version
+  # Returns true on success, false on failure
+  def revert_draft_to_live
+    # Return early if there's no draft to discard
+    return true unless form.live_with_draft?
+
+    live_form_data = form.live_form_document.content
+
+    ActiveRecord::Base.transaction do
+      revert_form_attributes(live_form_data)
+      revert_pages_and_nested_associations(live_form_data["steps"])
+
+      form.delete_draft_from_live_form
+      form.save!
+    end
+
+    true
+  rescue ActiveRecord::RecordInvalid => e
+    Rails.logger.error("Failed to discard draft for form #{form.id}: #{e.message}")
+    false
+  end
+
+private
+
+  # revert the top-level attributes of the Form object
+  def revert_form_attributes(live_data)
+    attributes_to_update = live_data.slice(*FORM_ATTRIBUTES_TO_REVERT)
+    form.assign_attributes(attributes_to_update)
+  end
+
+  # synchronize all pages and their nested routing conditions
+  def revert_pages_and_nested_associations(live_steps_data)
+    # ensure we have the latest version of pages
+    form.pages.reload
+
+    live_step_ids = live_steps_data.pluck("id")
+
+    # delete any pages on the form that are not present in the live version
+    form.pages.where.not(id: live_step_ids).destroy_all
+
+    # iterate through the live data to create or update pages
+    live_steps_data.each do |step_data|
+      page = form.pages.find_or_initialize_by(id: step_data["id"])
+
+      assign_page_attributes(page, step_data)
+      synchronize_routing_conditions_for_page(page, step_data["routing_conditions"] || [])
+
+      page.save!
+    end
+  end
+
+  # steps in a formDocument store the page attributes under "data"
+  def assign_page_attributes(page, step_data)
+    page_data = step_data["data"]
+    page.assign_attributes(
+      position: step_data["position"],
+      question_text: page_data["question_text"],
+      hint_text: page_data["hint_text"],
+      answer_type: page_data["answer_type"],
+      is_optional: page_data["is_optional"],
+      answer_settings: page_data["answer_settings"],
+      page_heading: page_data["page_heading"],
+      guidance_markdown: page_data["guidance_markdown"],
+      is_repeatable: page_data["is_repeatable"],
+    )
+  end
+
+  # synchronize the routing conditions for a single page
+  def synchronize_routing_conditions_for_page(page, live_conditions_data)
+    live_condition_ids = live_conditions_data.pluck("id")
+
+    # remove any conditions which have been added to the draft but are not in the live data
+    page.routing_conditions.where.not(id: live_condition_ids).destroy_all
+
+    # create or update conditions from the live data
+    live_conditions_data.each do |condition_data|
+      condition = Condition.find_by(id: condition_data["id"]) ||
+        page.routing_conditions.build(id: condition_data["id"])
+
+      condition.assign_attributes(
+        answer_value: condition_data["answer_value"],
+        routing_page_id: condition_data["routing_page_id"],
+        check_page_id: condition_data["check_page_id"],
+        goto_page_id: condition_data["goto_page_id"],
+      )
+      condition.save!
+    end
+  end
+end

app/state_machines/form_state_machine.rb

@@ -58,6 +58,10 @@ module FormStateMachine
         transitions from: :live, to: :archived
         transitions from: :live_with_draft, to: :archived_with_draft
       end
+
+      event :delete_draft_from_live_form do
+        transitions from: :live_with_draft, to: :live
+      end
     end
   end
 end

app/views/forms/delete_confirmation/delete.html.erb

@@ -3,11 +3,13 @@
 
 <div class="govuk-grid-row">
   <div class="govuk-grid-column-two-thirds">
+    <% hint_text = t(".hint_for_live_draft") if @current_form&.live_with_draft? %>
     <%= render(
       @delete_confirmation_input,
       url: @url,
       caption_text: @item_name,
       legend_text: t(".title"),
+      hint_text: hint_text,
     ) %>
   </div>
 </div>

app/views/forms/show.html.erb

@@ -41,6 +41,8 @@
                                            sections: @task_list)
     %>
 
-    <%= govuk_button_link_to(t("forms.delete_form"), delete_form_path(current_form.id), warning: true) if current_form.state.to_sym == :draft %>
+  <% if current_form.draft? or current_form.live_with_draft? %>
+    <%= govuk_button_link_to(t("forms.delete_form"), delete_form_path(current_form.id), warning: true) %>
+  <% end %>
   </div>
 </div>

app/views/input_objects/_delete_confirmation_input.html.erb

@@ -3,9 +3,18 @@
     <%= f.govuk_error_summary %>
   <% end %>
   <span class="govuk-caption-l"><%= caption_text %></span>
+  <%
+    options = {
+      legend: { text: legend_text, size: 'l', tag: 'h1' }
+    }
+
+    if local_assigns.key?(:hint_text) && hint_text.present?
+      options[:hint] = { text: hint_text }
+    end
+  %>
   <%= f.govuk_collection_radio_buttons :confirm,
                                        delete_confirmation_input.values, ->(option) { option }, ->(option) { t('helpers.label.confirm_action_input.options.' + "#{option}") },
-                                       legend: { text: legend_text, size: 'l', tag: 'h1' }
+                                       **options
                                        %>
 
   <%= f.govuk_submit local_assigns.fetch(:submit_text, t(:continue)) %>

config/locales/en.yml

@@ -347,6 +347,7 @@ en:
   forms:
     delete_confirmation:
       delete:
+        hint_for_live_draft: Deleting this draft will not remove the live form.
         title: Are you sure you want to delete this draft?
       destroy:
         success: The draft form, ‘%{form_name}’, has been deleted

spec/services/revert_draft_form_service_spec.rb

@@ -0,0 +1,134 @@
+require "rails_helper"
+# require "helpers/revert_to_live_state_matcher"
+
+RSpec::Matchers.define :be_reverted_to_live_state do
+  match do |form|
+    # reload the form to get the latest state from the database
+    reloaded_form = form.reload
+
+    # the form should be live
+    is_live = reloaded_form.live?
+
+    # We convert the form to a form document and compare the content
+    # to the live form document content and check they match baring the live_at times
+    # this is the closest we can get to saying there is no changes to the form
+    document_matches = reloaded_form.as_form_document.except("live_at") == form.live_form_document.content.except("live_at")
+
+    is_live && document_matches
+  end
+end
+
+describe RevertDraftFormService do
+  subject(:revert_draft_to_live_form_service) { described_class.new(form) }
+
+  let(:form) { create(:form, :live_with_draft) }
+
+  delegate :revert_draft_to_live, to: :revert_draft_to_live_form_service
+
+  # we use `freeze_time` to freeze the timestamps of the form and its pages
+  # reverting a draft will not keep the timestamps from the live version
+  around { |example| freeze_time { example.run } }
+
+  context "when the draft has no changes" do
+    it "reverts the form to its live state" do
+      revert_draft_to_live
+      expect(form).to be_reverted_to_live_state
+    end
+  end
+
+  context "when a form attribute is changed in the draft" do
+    before do
+      form.update!(name: "A new draft name")
+    end
+
+    it "reverts the attribute change" do
+      revert_draft_to_live
+      expect(form).to be_reverted_to_live_state
+    end
+  end
+
+  context "when a page attribute is changed in the draft" do
+    before do
+      form.pages.first.update!(question_text: "A new draft question text")
+    end
+
+    it "reverts the page change" do
+      revert_draft_to_live
+      expect(form).to be_reverted_to_live_state
+    end
+  end
+
+  context "when a page is added to the draft" do
+    before do
+      form.pages.create!(answer_type: "text", question_text: "A new page added to the draft", is_optional: false)
+    end
+
+    it "removes the added page" do
+      revert_draft_to_live
+      expect(form).to be_reverted_to_live_state
+    end
+  end
+
+  context "when a page is removed from the draft" do
+    before do
+      form.pages.last.destroy!
+    end
+
+    it "re-adds the removed page" do
+      revert_draft_to_live
+      expect(form).to be_reverted_to_live_state
+    end
+  end
+
+  context "with routing conditions" do
+    let(:form) { create(:form, :ready_for_live, pages_count: 2) }
+
+    before do
+      # live version with a routing condition
+      form.pages.first.routing_conditions.create!(
+        answer_value: "Yes",
+        goto_page_id: form.pages.last.id,
+        routing_page_id: form.pages.first.id,
+      )
+      FormDocument.create!(form:, tag: "live", content: form.as_form_document(live_at: form.updated_at))
+      form.update!(state: :live_with_draft)
+    end
+
+    context "when a routing condition is added to the draft" do
+      before do
+        form.pages.first.routing_conditions.create!(
+          answer_value: "No",
+          goto_page_id: form.pages.last.id,
+          routing_page_id: form.pages.first.id,
+        )
+      end
+
+      it "removes the added routing condition" do
+        revert_draft_to_live
+        expect(form).to be_reverted_to_live_state
+      end
+    end
+
+    context "when a routing condition is removed from the draft" do
+      before do
+        form.pages.first.routing_conditions.first.destroy!
+      end
+
+      it "re-adds the removed routing condition" do
+        revert_draft_to_live
+        expect(form).to be_reverted_to_live_state
+      end
+    end
+
+    context "when a routing condition is changed in the draft" do
+      before do
+        form.pages.first.routing_conditions.first.update!(answer_value: "Maybe")
+      end
+
+      it "reverts the changed routing condition" do
+        revert_draft_to_live
+        expect(form).to be_reverted_to_live_state
+      end
+    end
+  end
+end

spec/views/input_objects/_delete_confirmation_input.html.erb_spec.rb

@@ -1,13 +1,15 @@
 require "rails_helper"
 
 RSpec.describe "input_objects/_delete_confirmation_input" do
+  let(:hint_text) { nil }
+
   before do
     delete_confirmation_input = DeleteConfirmationInput.new
     url = "/delete"
     caption_text = "Thing"
     legend_text = "Are you sure you want to delete this thing?"
 
-    render locals: { delete_confirmation_input:, url:, caption_text:, legend_text: }
+    render locals: { delete_confirmation_input:, url:, caption_text:, legend_text:, hint_text: }
   end
 
   it "posts the confirm value to the destroy action" do
@@ -28,4 +30,18 @@
   it "has a submit button" do
     expect(rendered).to have_button "Continue", class: "govuk-button"
   end
+
+  context "when no hint_text is provided" do
+    it "doesn't have a hint" do
+      expect(rendered).not_to have_css "fieldset legend:has(~ .govuk-hint)"
+    end
+  end
+
+  context "when hint_text is provided" do
+    let(:hint_text) { "This is a hint" }
+
+    it "has a hint" do
+      expect(rendered).to have_css ".govuk-hint", text: "This is a hint"
+    end
+  end
 end