feat(marketplace): add read-only listing and question preview

app/controllers/components/course/assessment_marketplace_component.rb

@@ -11,7 +11,7 @@ def sidebar_items
 
     [
       key: :admin_marketplace,
-      icon: :duplication,
+      icon: :marketplace,
       type: :admin,
       weight: 6,
       path: course_marketplace_path(current_course)

app/controllers/components/course/gradebook_component.rb

@@ -16,26 +16,22 @@ def main_sidebar_items
     return [] unless can?(:read_gradebook, current_course)
 
     [
-      {
-        key: self.class.key,
-        icon: :gradebook,
-        type: :normal,
-        weight: 9,
-        path: course_gradebook_path(current_course)
-      }
+      key: self.class.key,
+      icon: :gradebook,
+      type: :normal,
+      weight: 9,
+      path: course_gradebook_path(current_course)
     ]
   end
 
   def settings_sidebar_items
     return [] unless can?(:manage_gradebook_settings, current_course)
 
     [
-      {
-        key: self.class.key,
-        type: :settings,
-        weight: 14,
-        path: course_admin_gradebook_path(current_course)
-      }
+      key: self.class.key,
+      type: :settings,
+      weight: 14,
+      path: course_admin_gradebook_path(current_course)
     ]
   end
 end

app/controllers/course/assessment/marketplace/controller.rb

@@ -1,5 +1,9 @@
 # frozen_string_literal: true
 class Course::Assessment::Marketplace::Controller < Course::ComponentController
+  # display_graded_test_types is defined in Course::Assessment::AssessmentsHelper; the marketplace
+  # preview views reuse it, but Rails only auto-includes a controller's own matching helper.
+  helper Course::Assessment::AssessmentsHelper
+
   private
 
   def component

app/controllers/course/assessment/marketplace/listings_controller.rb

@@ -4,18 +4,14 @@ class Course::Assessment::Marketplace::ListingsController < Course::Assessment::
 
   def index
     ActsAsTenant.without_tenant do
-      @listings = Course::Assessment::Marketplace::Listing.published.includes(:assessment).to_a
-      listing_ids = @listings.map(&:id)
-      assessment_ids = @listings.map(&:assessment_id)
-      @adoption_counts = Course::Assessment::Marketplace::Adoption.
-                         where(listing_id: listing_ids).group(:listing_id).
-                         distinct.count(:destination_course_id)
-      # reorder(nil) strips QuestionAssessment's `default_scope { order(weight: :asc) }`; without it
-      # the injected `ORDER BY weight` breaks the grouped aggregate (PG::GroupingError — weight is
-      # neither grouped nor aggregated).
-      @question_counts = Course::QuestionAssessment.
-                         where(assessment_id: assessment_ids).reorder(nil).group(:assessment_id).
-                         distinct.count(:question_id)
+      # Preload `lesson_plan_item` — `title` is not a column on Course::Assessment; it lives on
+      # the acting-as record. The source course is deliberately NOT preloaded: the MVP exposes no
+      # attribution, so nothing in the view reaches for it.
+      @listings = Course::Assessment::Marketplace::Listing.published.
+                  includes(assessment: :lesson_plan_item).to_a
+      @adoption_counts = adoption_counts(@listings.map(&:id))
+      @question_counts = question_counts(@listings.map(&:assessment_id))
+      @destination_tabs = destination_tabs
     end
   end
 
@@ -28,12 +24,46 @@ def duplicate
     render partial: 'jobs/submitted', locals: { job: job }
   end
 
+  def show
+    ActsAsTenant.without_tenant do
+      @listing = Course::Assessment::Marketplace::Listing.published.includes(:assessment).find_by(id: params[:id])
+      raise CanCan::AccessDenied unless @listing
+
+      @assessment = @listing.assessment
+      authorize!(:preview_in_marketplace, @assessment)
+      render 'show'
+    end
+  end
+
   private
 
   def authorize_access!
     authorize!(:access_marketplace, current_course)
   end
 
+  def adoption_counts(listing_ids)
+    Course::Assessment::Marketplace::Adoption.
+      where(listing_id: listing_ids).group(:listing_id).
+      distinct.count(:destination_course_id)
+  end
+
+  def question_counts(assessment_ids)
+    # reorder(nil) strips QuestionAssessment's `default_scope { order(weight: :asc) }`; without it
+    # the injected `ORDER BY weight` breaks the grouped aggregate (PG::GroupingError — weight is
+    # neither grouped nor aggregated).
+    Course::QuestionAssessment.
+      where(assessment_id: assessment_ids).reorder(nil).group(:assessment_id).
+      distinct.count(:question_id)
+  end
+
+  def destination_tabs
+    current_course.assessment_categories.includes(:tabs).flat_map do |category|
+      category.tabs.map do |tab|
+        { id: tab.id, title: tab.title, category_id: category.id, category_title: category.title }
+      end
+    end
+  end
+
   def authorized_listings
     listings = ActsAsTenant.without_tenant do
       Course::Assessment::Marketplace::Listing.published.where(id: duplicate_params[:listing_ids]).includes(:assessment)

app/controllers/course/assessment/marketplace/questions_controller.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+class Course::Assessment::Marketplace::QuestionsController < Course::Assessment::Marketplace::Controller
+  before_action :authorize_access!
+
+  def show
+    ActsAsTenant.without_tenant do
+      listing = Course::Assessment::Marketplace::Listing.published.includes(:assessment).
+                find_by(id: params[:listing_id])
+      raise CanCan::AccessDenied unless listing
+
+      @assessment = listing.assessment
+      authorize!(:preview_in_marketplace, @assessment)
+
+      @question = @assessment.questions.includes(:actable).find(params[:id])
+      @question_assessment = @question.question_assessments.find_by!(assessment: @assessment)
+      render 'show' # rendered inside without_tenant so actable associations resolve cross-instance
+    end
+  end
+
+  private
+
+  def authorize_access!
+    authorize!(:access_marketplace, current_course)
+  end
+end

app/controllers/course/statistics/aggregate_controller.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 # This is named aggregate controller as naming this as course controller leads to name conflict issues
-class Course::Statistics::AggregateController < Course::Statistics::Controller
+class Course::Statistics::AggregateController < Course::Statistics::Controller # rubocop:disable Metrics/ClassLength
   before_action :preload_levels, only: [:all_students, :course_performance]
   include Course::Statistics::TimesConcern
   include Course::Statistics::GradesConcern
@@ -169,7 +169,7 @@ def correctness_hash
         id
     SQL
                                   )
-    query.map { |u| [u.id, u.correctness] }.to_h
+    query.to_h { |u| [u.id, u.correctness] }
   end
 
   def fetch_all_assessment_related_statistics_hash

app/views/course/assessment/marketplace/listings/index.json.jbuilder

@@ -11,3 +11,9 @@ json.listings @listings do |listing|
   json.previewUrl course_listing_path(current_course, listing)
   json.duplicateUrl duplicate_course_listings_path(current_course)
 end
+json.destinationTabs @destination_tabs do |tab|
+  json.id tab[:id]
+  json.title tab[:title]
+  json.categoryId tab[:category_id]
+  json.categoryTitle tab[:category_title]
+end

app/views/course/assessment/marketplace/listings/show.json.jbuilder

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+json.id @assessment.id
+json.title @assessment.title
+json.description format_ckeditor_rich_text(@assessment.description)
+
+json.gradingMode @assessment.autograded? ? 'autograded' : 'manual'
+json.baseExp @assessment.base_exp if @assessment.base_exp > 0
+json.bonusExp @assessment.time_bonus_exp if @assessment.time_bonus_exp > 0
+json.showMcqMrqSolution @assessment.show_mcq_mrq_solution
+json.showRubricToStudents @assessment.show_rubric_to_students
+json.gradedTestCases display_graded_test_types(@assessment)
+
+questions = @assessment.questions.includes(:actable)
+
+# Group by the human-readable type (e.g. "Multiple Choice", "Text Response Question") so the
+# breakdown matches the per-question chips and the wording of the real assessment show page,
+# instead of raw actable class names ("MultipleResponse").
+json.typeCounts questions.group_by(&:question_type_readable).transform_values(&:size)
+
+json.questions questions do |question|
+  json.id question.id
+  json.title question.title
+  json.description format_ckeditor_rich_text(question.description)
+  json.staffOnlyComments format_ckeditor_rich_text(question.staff_only_comments)
+  json.maximumGrade question.maximum_grade
+  # Human-readable label for the type chip, mirroring _question_assessment.json.jbuilder. The
+  # renderer dispatch lives on the detail endpoint (which keeps the demodulized discriminator).
+  json.type question.question_type_readable
+  json.unautogradable !question.auto_gradable?
+
+  if question.actable_type == 'Course::Assessment::Question::MultipleResponse'
+    mrq = question.actable
+    json.mcqMrqType mrq.multiple_choice? ? 'mcq' : 'mrq' # multiple_choice? is aliased to any_correct?
+    json.options mrq.options do |option|
+      json.id option.id
+      json.option format_ckeditor_rich_text(option.option)
+      json.correct option.correct
+    end
+  end
+end

app/views/course/assessment/marketplace/questions/details/_forum_post_response.json.jbuilder

@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+json.maxPosts question.max_posts
+json.hasTextResponse question.has_text_response

app/views/course/assessment/marketplace/questions/details/_multiple_response.json.jbuilder

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+json.gradingScheme question.grading_scheme
+json.options question.options do |option|
+  json.id option.id
+  json.option format_ckeditor_rich_text(option.option)
+  json.correct option.correct
+  json.explanation format_ckeditor_rich_text(option.explanation)
+  json.weight option.weight
+end

app/views/course/assessment/marketplace/questions/details/_programming.json.jbuilder

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+json.languageName question.language&.name
+json.memoryLimit question.memory_limit
+json.timeLimit question.time_limit
+
+json.templateFiles question.template_files do |file|
+  json.filename file.filename
+  json.content file.content
+end
+
+grouped = question.test_cases.group_by(&:test_case_type)
+{ 'publicTestCases' => 'public_test',
+  'privateTestCases' => 'private_test',
+  'evaluationTestCases' => 'evaluation_test' }.each do |key, type|
+  json.set! key, (grouped[type] || []) do |tc|
+    json.identifier tc.identifier
+    json.expression tc.expression
+    json.expected tc.expected
+    json.hint tc.hint
+  end
+end

app/views/course/assessment/marketplace/questions/details/_rubric_based_response.json.jbuilder

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+json.categories question.categories do |category|
+  json.name category.name
+  json.isBonus category.is_bonus_category
+  json.criteria category.criterions do |criterion|
+    json.grade criterion.grade
+    json.explanation format_ckeditor_rich_text(criterion.explanation)
+  end
+end

app/views/course/assessment/marketplace/questions/details/_scribing.json.jbuilder

@@ -0,0 +1,4 @@
+# frozen_string_literal: true
+# Verified against app/views/course/assessment/question/scribing/_scribing_question.json.jbuilder:
+# scribing exposes its image via `attachment_reference.generate_public_url`, guarded by presence.
+json.imageUrl question.attachment_reference&.generate_public_url

app/views/course/assessment/marketplace/questions/details/_text_response.json.jbuilder

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+json.hideText question.hide_text
+json.isAttachmentRequired question.is_attachment_required
+json.maxAttachments question.max_attachments
+json.maxAttachmentSize question.max_attachment_size
+json.isComprehension question.is_comprehension
+json.solutions question.solutions do |solution|
+  json.solutionType solution.solution_type
+  json.solution format_ckeditor_rich_text(solution.solution)
+  json.grade solution.grade
+  json.explanation format_ckeditor_rich_text(solution.explanation)
+end

app/views/course/assessment/marketplace/questions/details/_voice_response.json.jbuilder

@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+# Voice questions have no type-specific setup fields; the base prompt is shown by the shell.
+# `json.merge!({})` forces the enclosing `json.detail do … end` block to serialize as an empty
+# object `{}`. Without it the block's scope stays blank and jbuilder emits `null` instead.
+json.merge!({})

app/views/course/assessment/marketplace/questions/show.json.jbuilder

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+detail_partials = {
+  'Course::Assessment::Question::MultipleResponse' => 'multiple_response',
+  'Course::Assessment::Question::Programming' => 'programming',
+  'Course::Assessment::Question::TextResponse' => 'text_response',
+  'Course::Assessment::Question::RubricBasedResponse' => 'rubric_based_response',
+  'Course::Assessment::Question::ForumPostResponse' => 'forum_post_response',
+  'Course::Assessment::Question::VoiceResponse' => 'voice_response',
+  'Course::Assessment::Question::Scribing' => 'scribing'
+}
+
+json.id @question.id
+json.title @question.title
+json.defaultTitle @question_assessment.default_title(@question_assessment.question_number)
+json.description format_ckeditor_rich_text(@question.description)
+json.staffOnlyComments format_ckeditor_rich_text(@question.staff_only_comments)
+json.maximumGrade @question.maximum_grade
+# `type` is the demodulized discriminator that drives the frontend renderer dispatch; keep it stable.
+json.type @question.actable_type.demodulize
+# `displayType` is the human-readable label shown in the detail header chip (mirrors the card).
+json.displayType @question.question_type_readable
+
+partial = detail_partials[@question.actable_type]
+if partial
+  json.detail do
+    json.partial! "course/assessment/marketplace/questions/details/#{partial}", question: @question.actable
+  end
+else
+  json.detail nil
+end

client/app/api/course/Marketplace.ts

@@ -1,6 +1,6 @@
 import { AxiosResponse } from 'axios';
 
-import { MarketplaceListing } from 'course/marketplace/types';
+import { DestinationTab, MarketplaceListing } from 'course/marketplace/types';
 
 import BaseCourseAPI from './Base';
 
@@ -22,7 +22,11 @@ export default class MarketplaceAPI extends BaseCourseAPI {
   }
 
   index(): Promise<
-    AxiosResponse<{ listings: MarketplaceListing[]; canAccess: boolean }>
+    AxiosResponse<{
+      listings: MarketplaceListing[];
+      destinationTabs: DestinationTab[];
+      canAccess: boolean;
+    }>
   > {
     return this.client.get(this.#urlPrefix);
   }
@@ -36,4 +40,14 @@ export default class MarketplaceAPI extends BaseCourseAPI {
       ...(destinationTabId ? { destination_tab_id: destinationTabId } : {}),
     });
   }
+
+  fetchListing(id: number): Promise<AxiosResponse> {
+    return this.client.get(`${this.#urlPrefix}/listings/${id}`);
+  }
+
+  fetchQuestion(listingId: number, questionId: number): Promise<AxiosResponse> {
+    return this.client.get(
+      `${this.#urlPrefix}/listings/${listingId}/questions/${questionId}`,
+    );
+  }
 }