Scratch projects create action for remixing

This is based on the similar endpoint in Experience CS.

Having this will allowed me to test the behaviour of Scratch remixing locally and it will allow us to start work implementing remixing on the frontend before the API is fully implemented.

I considered re-using our existing endpoint for remixing, but this is not possible because Scratch does not support updating an unsaved project's id (see [1] for more).

[1] - RaspberryPiFoundation/digital-editor-issues#1189 (comment)

Author: zetter-rpf

app/controllers/api/scratch/projects_controller.rb

@@ -7,16 +7,30 @@ class ProjectsController < ScratchController
       skip_before_action :check_scratch_feature, only: [:show]
       before_action :load_project, only: %i[show update]
 
+      before_action :ensure_create_is_a_remix, only: %i[create]
+
       def show
         render json: @project.scratch_component.content
       end
 
+      def create
+        render json: { status: 'ok', 'content-name': 'new-project-id' }, status: :ok
+      end
+
       def update
         scratch_content = params.permit!.slice(:meta, :targets, :monitors, :extensions)
         @project.scratch_component&.content = scratch_content.to_unsafe_h
         @project.save!
         render json: { status: 'ok' }, status: :ok
       end
+
+      private
+
+      def ensure_create_is_a_remix
+        return if params[:is_remix] == '1'
+
+        render json: { error: 'Only remixing existing projects is allowed' }, status: :forbidden
+      end
     end
   end
 end

config/routes.rb

@@ -34,7 +34,7 @@
 
   namespace :api do
     namespace :scratch do
-      resources :projects, only: %i[show update]
+      resources :projects, only: %i[show update create]
       get '/assets/internalapi/asset/:id(.:format)/get/' => 'assets#show'
       post '/assets/:id' => 'assets#create'
     end

spec/features/scratch/creating_a_scratch_project_spec.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe 'Creating a Scratch project (remixing)', type: :request do
+  let(:school) { create(:school) }
+  let(:teacher) { create(:teacher, school:) }
+  let(:cookie_headers) { { 'Cookie' => "scratch_auth=#{UserProfileMock::TOKEN}" } }
+  let(:params) { { original_id: 'original-project-id', project: { targets: [] }, is_remix: '1' } }
+
+  before do
+    Flipper.disable :cat_mode
+    Flipper.disable_actor :cat_mode, school
+  end
+
+  it 'responds 401 Unauthorized when no cookie is provided' do
+    post '/api/scratch/projects', params: params
+
+    expect(response).to have_http_status(:unauthorized)
+  end
+
+  it 'responds 404 Not Found when cat_mode is not enabled' do
+    authenticated_in_hydra_as(teacher)
+
+    post '/api/scratch/projects', params: params, headers: cookie_headers
+
+    expect(response).to have_http_status(:not_found)
+  end
+
+  it 'responds 403 Forbidden when not remixing' do
+    authenticated_in_hydra_as(teacher)
+    Flipper.enable_actor :cat_mode, school
+
+    post '/api/scratch/projects', params: params.merge(is_remix: '0'), headers: cookie_headers
+
+    expect(response).to have_http_status(:forbidden)
+  end
+
+  it 'return new project id when cat_mode is enabled and a cookie is provided' do
+    authenticated_in_hydra_as(teacher)
+    Flipper.enable_actor :cat_mode, school
+
+    post '/api/scratch/projects', params: params, headers: cookie_headers
+
+    expect(response).to have_http_status(:ok)
+
+    data = JSON.parse(response.body, symbolize_names: true)
+    expect(data[:status]).to eq('ok')
+    expect(data[:'content-name']).to eq('new-project-id')
+  end
+end