Fix submitted projects n plus 1

.vscode/tasks.json

@@ -0,0 +1,41 @@
+{
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "label": "Run test file (RSpec)",
+      "type": "shell",
+      "command": "./bin/rspec",
+      "args": [
+        "${file}"
+      ],
+      "options": {
+        "cwd": "${workspaceFolder}"
+      },
+      "group": "test",
+      "presentation": {
+        "reveal": "always",
+        "panel": "dedicated",
+        "clear": true
+      },
+      "problemMatcher": []
+    },
+    {
+      "label": "Run test at current line (RSpec)",
+      "type": "shell",
+      "command": "./bin/rspec",
+      "args": [
+        "${file}:${lineNumber}"
+      ],
+      "options": {
+        "cwd": "${workspaceFolder}"
+      },
+      "group": "test",
+      "presentation": {
+        "reveal": "always",
+        "panel": "dedicated",
+        "clear": true
+      },
+      "problemMatcher": []
+    }
+  ]
+}

app/controllers/api/lessons_controller.rb

@@ -11,13 +11,15 @@ class LessonsController < ApiController
     def index
       accessible_lessons = filtered_lessons_scope
                            .accessible_by(current_ability)
-                           .includes(project: :remixes)
-      @lessons_with_users = accessible_lessons.with_users
 
       if current_user&.school_teacher?(school) || current_user&.school_owner?(school)
+        accessible_lessons = accessible_lessons.includes(project: { remixes: %i[submitted_school_project] })
+        @lessons_with_users = accessible_lessons.with_users
         render :teacher_index, formats: [:json], status: :ok
       else
         remixes = user_remixes(accessible_lessons)
+        accessible_lessons = accessible_lessons.includes(project: :remixes)
+        @lessons_with_users = accessible_lessons.with_users
         @lessons_with_users_and_remixes = @lessons_with_users.zip(remixes)
         render :student_index, formats: [:json], status: :ok
       end

app/models/lesson.rb

@@ -35,7 +35,7 @@ def with_user
   def submitted_count
     return 0 unless project
 
-    project.remixes.count { |remix| remix.school_project&.submitted? }
+    project.remixes.count(&:submitted_school_project)
   end
 
   private

app/models/project.rb

@@ -19,6 +19,7 @@ module Types
   has_many_attached :videos
   has_many_attached :audio
   has_one :school_project, dependent: :destroy
+  has_one :submitted_school_project, -> { in_state(:submitted) }, class_name: 'SchoolProject', dependent: :destroy, inverse_of: :project
 
   accepts_nested_attributes_for :components
   accepts_nested_attributes_for :scratch_component

bin/rspec

@@ -0,0 +1,16 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+#
+# This file was generated by Bundler.
+#
+# The application 'rspec' is installed as part of a gem, and
+# this file is here to facilitate running it.
+#
+
+ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../Gemfile", __dir__)
+
+require "rubygems"
+require "bundler/setup"
+
+load Gem.bin_path("rspec-core", "rspec")

spec/features/lesson/listing_lessons_spec.rb

@@ -86,14 +86,20 @@
   end
 
   it 'includes the submitted_count for each lesson' do
+    student_2 = create(:student, school:)
+    create(:class_student, school_class:, student_id: student_2.id)
+
     lesson.update!(school_class_id: school_class.id)
-    remix = create(:project, school:, remixed_from_id: lesson.project.id, user_id: student.id)
-    remix.school_project.transition_status_to!(:submitted, student.id)
+
+    [student, student_2].each do |student|
+      remix = create(:project, school:, remixed_from_id: lesson.project.id, user_id: student.id)
+      remix.school_project.transition_status_to!(:submitted, student.id)
+    end
 
     get("/api/lessons?school_class_id=#{school_class.id}", headers:)
     data = JSON.parse(response.body, symbolize_names: true)
 
-    expect(data.first[:submitted_count]).to eq(1)
+    expect(data.first[:submitted_count]).to eq(2)
   end
 
   context 'when filtering by project_identifier' do