Add a way to reach specific training modules and slides via ID numbers

app/controllers/training_controller.rb

@@ -5,6 +5,7 @@
 require_dependency "#{Rails.root}/lib/training/training_resource_query_object"
 
 class TrainingController < ApplicationController
+  include TrainingHelper
   layout 'training'
   before_action :init_query_object, only: :index
 
@@ -59,6 +60,15 @@ def reload
     render plain: e.message
   end
 
+  def find_slide
+    training_slide = TrainingSlide.find(params[:slide_id])
+    training_module = find_module_from_slide_slug(training_slide.slug)
+    raise ActionController::RoutingError, 'module not found' unless training_module
+    training_library = find_library_from_module_slug(training_module.slug)
+    raise ActionController::RoutingError, 'library not found' unless training_library
+    redirect_to "/training/#{training_library.slug}/#{training_module.slug}/#{training_slide.slug}"
+  end
+
   private
 
   def add_training_root_breadcrumb

app/controllers/training_modules_controller.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 class TrainingModulesController < ApplicationController
+  include TrainingHelper
   respond_to :json
 
   def index
@@ -11,4 +12,11 @@ def index
   def show
     @training_module = TrainingModule.find_by(slug: params[:module_id])
   end
+
+  def find
+    training_module = TrainingModule.find(params[:module_id])
+    training_library = find_library_from_module_slug(training_module.slug)
+    raise ActionController::RoutingError, 'library not found' unless training_library
+    redirect_to "/training/#{training_library.slug}/#{training_module.slug}"
+  end
 end

app/helpers/training_helper.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+#= Helpers for training views
+module TrainingHelper
+  # Given a module slug, it returns the first library that has a
+  # category including that module slug. It returns nil if no such
+  # library is found.
+  def find_library_from_module_slug(module_slug)
+    TrainingLibrary.all.find_each do |library|
+      library.categories.each do |category|
+        next unless category.key?('modules')
+        category['modules'].each do |mod|
+          return library if mod['slug'] == module_slug
+        end
+      end
+    end
+  end
+
+  # Given a slide slug, it returns the first module including it.
+  # It returns nil if no such module is found.
+  def find_module_from_slide_slug(slide_slug_to_find)
+    TrainingModule.all.find_each do |mod|
+      mod.slide_slugs.each do |slide_slug|
+        return mod if slide_slug == slide_slug_to_find
+      end
+    end
+  end
+end

config/routes.rb

@@ -328,6 +328,11 @@
   get 'training_modules' => 'training_modules#index'
   get 'training_module' => 'training_modules#show'
 
+  # To find training modules by id
+  get 'find_training_module/:module_id' => 'training_modules#find'
+
+  # To find individual slides by id
+  get 'find_training_slide/:slide_id' => 'training#find_slide'
 
   # Misc
   # get 'courses' => 'courses#index'

spec/controllers/training_controller_spec.rb

@@ -140,4 +140,72 @@
       end
     end
   end
+
+  describe '#find' do
+    subject { get "/find_training_module/#{module_id}" }
+
+    context 'module_id is found' do
+      let(:module_id) { 12 }
+
+      it 'redirects to a training module page' do
+        subject
+        expect(response).to redirect_to('/training/students/peer-review')
+      end
+    end
+
+    context 'module_id is found but it is in no library' do
+      let(:module_id) { 2 }
+
+      it 'raises a routing error' do
+        expect { subject }.to raise_error ActionController::RoutingError
+      end
+    end
+
+    context 'module_id is not found' do
+      let(:module_id) { 128456 }
+
+      it 'raises a module not found error' do
+        expect { subject }.to raise_error ActiveRecord::RecordNotFound
+      end
+    end
+  end
+
+  describe '#find_slide' do
+    subject { get "/find_training_slide/#{slide_id}" }
+
+    context 'slide_id is found' do
+      let(:slide_id) { 332 }
+
+      it 'redirects to a training slide page' do
+        subject
+        expect(response).to redirect_to('/training/instructors/new-instructor-orientation/' \
+                                        'new-instructor-orientation-complete')
+      end
+    end
+
+    context 'slide_id is found but it is in no module' do
+      let(:slide) { create(:training_slide) }
+      let(:slide_id) { slide.id }
+
+      it 'raises a routing error' do
+        expect { subject }.to raise_error ActionController::RoutingError, 'module not found'
+      end
+    end
+
+    context 'slide_id is found but its module is in no library' do
+      let(:slide_id) { 201 }
+
+      it 'raises a routing error' do
+        expect { subject }.to raise_error ActionController::RoutingError, 'library not found'
+      end
+    end
+
+    context 'slide_id is not found' do
+      let(:slide_id) { 128456 }
+
+      it 'raises a module not found error' do
+        expect { subject }.to raise_error ActiveRecord::RecordNotFound
+      end
+    end
+  end
 end

spec/factories/training_slides.rb

@@ -19,5 +19,8 @@
 
 FactoryBot.define do
   factory :training_slide do
+    id { 456875 }
+    title { 'How to create a slide' }
+    slug { 'how-to-create-a-slide' }
   end
 end