Fix previewing quick actions for epics

- added args to preview_markdown path for groups
- changed epic.id to epic.iid for the path (same as other types)
- added Epic as supported type
- added feature specs covering basic quick action for epic

app/controllers/concerns/preview_markdown.rb

@@ -5,7 +5,7 @@ module PreviewMarkdown
 
   # rubocop:disable Gitlab/ModuleWithInstanceVariables
   def preview_markdown
-    result = PreviewMarkdownService.new(@project, current_user, params).execute
+    result = PreviewMarkdownService.new(@project, current_user, markdown_service_params).execute
 
     markdown_params =
       case controller_name
@@ -26,6 +26,8 @@ module PreviewMarkdown
   end
   # rubocop:enable Gitlab/ModuleWithInstanceVariables
 
+  private
+
   def projects_filter_params
     {
       issuable_state_filter_enabled: true,
@@ -33,10 +35,12 @@ module PreviewMarkdown
     }
   end
 
-  private
-
   # Override this method to customise the markdown for your controller
   def preview_markdown_params
     {}
   end
+
+  def markdown_service_params
+    params
+  end
 end

app/controllers/groups_controller.rb

@@ -6,6 +6,7 @@ class GroupsController < Groups::ApplicationController
   include ParamsBackwardCompatibility
   include PreviewMarkdown
   include RecordUserLastActivity
+  extend ::Gitlab::Utils::Override
 
   respond_to :html
 
@@ -233,6 +234,11 @@ class GroupsController < Groups::ApplicationController
       @group.self_and_descendants.public_or_visible_to_user(current_user)
     end
   end
+
+  override :markdown_service_params
+  def markdown_service_params
+    params.merge(group: group)
+  end
 end
 
 GroupsController.prepend_if_ee('EE::GroupsController')

app/helpers/gitlab_routing_helper.rb

@@ -66,7 +66,7 @@ module GitlabRoutingHelper
   end
 
   def preview_markdown_path(parent, *args)
-    return group_preview_markdown_path(parent) if parent.is_a?(Group)
+    return group_preview_markdown_path(parent, *args) if parent.is_a?(Group)
 
     if @snippet.is_a?(PersonalSnippet)
       preview_markdown_snippets_path

app/services/preview_markdown_service.rb

@@ -16,8 +16,12 @@ class PreviewMarkdownService < BaseService
 
   private
 
+  def quick_action_types
+    %w(Issue MergeRequest Commit)
+  end
+
   def explain_quick_actions(text)
-    return text, [] unless %w(Issue MergeRequest Commit).include?(target_type)
+    return text, [] unless quick_action_types.include?(target_type)
 
     quick_actions_service = QuickActions::InterpretService.new(project, current_user)
     quick_actions_service.explain(text, find_commands_target)
@@ -51,7 +55,7 @@ class PreviewMarkdownService < BaseService
 
   def find_commands_target
     QuickActions::TargetService
-      .new(project, current_user)
+      .new(project, current_user, group: params[:group])
       .execute(target_type, target_id)
   end
 
@@ -63,3 +67,5 @@ class PreviewMarkdownService < BaseService
     params[:target_id]
   end
 end
+
+PreviewMarkdownService.prepend_if_ee('EE::PreviewMarkdownService')

app/services/quick_actions/target_service.rb

@@ -32,3 +32,5 @@ module QuickActions
     end
   end
 end
+
+QuickActions::TargetService.prepend_if_ee('EE::QuickActions::TargetService')

changelogs/unreleased/8199-epic-quick-actions-preview.yml

+---
+title: Fix previewing quick actions for epics
+merge_request: 19042
+author:
+type: fixed

ee/app/serializers/epic_entity.rb

@@ -40,6 +40,6 @@ class EpicEntity < IssuableEntity
   end
 
   expose :preview_note_path do |epic|
-    preview_markdown_path(epic.group, target_type: 'Epic', target_id: epic.id)
+    preview_markdown_path(epic.group, target_type: 'Epic', target_id: epic.iid)
   end
 end

ee/app/services/ee/preview_markdown_service.rb

+# frozen_string_literal: true
+
+module EE
+  module PreviewMarkdownService
+    def quick_action_types
+      super.push('Epic')
+    end
+  end
+end

ee/app/services/ee/quick_actions/target_service.rb

+# frozen_string_literal: true
+
+module EE
+  module QuickActions
+    module TargetService
+      def execute(type, type_id)
+        return epic(type_id) if type.casecmp('epic').zero?
+
+        super
+      end
+
+      private
+
+      # rubocop: disable CodeReuse/ActiveRecord
+      def epic(type_id)
+        group = params[:group]
+        EpicsFinder.new(current_user, group_id: group.id).find_by(iid: type_id) || group.epics.build
+      end
+      # rubocop: enable CodeReuse/ActiveRecord
+    end
+  end
+end

ee/spec/features/discussion_comments/epic_quick_actions_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'Epic quick actions', :js do
+  include Spec::Support::Helpers::Features::NotesHelpers
+
+  let(:user) { create(:user) }
+  let(:group) { create(:group) }
+  let(:epic) { create(:epic, group: group) }
+
+  before do
+    stub_licensed_features(epics: true)
+    group.add_developer(user)
+
+    sign_in(user)
+    visit group_epic_path(group, epic)
+  end
+
+  context 'note with a quick action' do
+    it 'previews a note with quick action' do
+      preview_note('/title New Title')
+
+      expect(page).to have_content('Changes the title to "New Title".')
+    end
+
+    it 'executes the quick action' do
+      add_note('/title New Title')
+
+      expect(page).to have_content('Changed the title to "New Title".')
+      expect(epic.reload.title).to eq('New Title')
+
+      visit group_epic_path(group, epic)
+
+      expect(page).to have_content('New Title')
+    end
+  end
+end

ee/spec/services/ee/preview_markdown_service_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe PreviewMarkdownService do
+  context 'preview epic text with quick action' do
+    let(:user) { create(:user) }
+    let(:group) { create(:group) }
+    let(:epic) { create(:epic, group: group) }
+    let(:params) do
+      {
+        text: '/title new title',
+        target_type: 'Epic',
+        target_id: epic.iid,
+        group: epic.group
+      }
+    end
+    let(:service) { described_class.new(nil, user, params) }
+
+    before do
+      stub_licensed_features(epics: true)
+      group.add_developer(user)
+    end
+
+    it 'explains quick actions effect' do
+      result = service.execute
+
+      expect(result[:commands]).to eq 'Changes the title to "new title".'
+    end
+  end
+end

ee/spec/services/ee/quick_actions/target_service_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe QuickActions::TargetService do
+  let(:group) { create(:group) }
+  let(:project) { create(:project, group: group) }
+  let(:user) { create(:user) }
+  let(:service) { described_class.new(project, user, group: group) }
+
+  before do
+    group.add_maintainer(user)
+    stub_licensed_features(epics: true)
+  end
+
+  describe '#execute' do
+    context 'for epic' do
+      let(:type) { 'Epic' }
+
+      it 'finds target with valid id' do
+        epic = create(:epic, group: group)
+
+        target = service.execute(type, epic.iid)
+
+        expect(target).to eq(epic)
+      end
+
+      it 'builds a new target if id from a different group passed' do
+        epic = create(:epic)
+
+        target = service.execute(type, epic.iid)
+
+        expect(target).to be_new_record
+        expect(target.group).to eq(group)
+      end
+    end
+  end
+end

spec/helpers/gitlab_routing_helper_spec.rb

@@ -75,6 +75,12 @@ describe GitlabRoutingHelper do
       expect(preview_markdown_path(group)).to eq("/groups/#{group.path}/preview_markdown")
     end
 
+    it 'returns group preview markdown path for a group parent with args' do
+      group = create(:group)
+
+      expect(preview_markdown_path(group, { type_id: 5 })).to eq("/groups/#{group.path}/preview_markdown?type_id=5")
+    end
+
     it 'returns project preview markdown path for a project parent' do
       expect(preview_markdown_path(project)).to eq("/#{project.full_path}/preview_markdown")
     end