Add Reviews to Subjects

app/assets/stylesheets/_rating.scss

@@ -0,0 +1,26 @@
+.rating-container {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  width: 100%;
+  gap: 12px;
+}
+
+.rating-item {
+  display: flex;
+  align-items: center;
+}
+
+.interactive-star {
+  transition: transform 0.25s ease;
+
+  &:hover {
+    transform: scale(1.3);
+  }
+}
+
+.login-container {
+  display: flex;
+  gap: 4px;
+  align-items: center;
+}

app/controllers/reviews_controller.rb

@@ -0,0 +1,28 @@
+class ReviewsController < ApplicationController
+  before_action :authenticate_user!
+  before_action :set_review, only: [:update, :destroy]
+
+  def create
+    @review = current_user.reviews.create!(subject_id: params[:subject_id], rating: params[:rating])
+
+    redirect_to subject_path(@review.subject)
+  end
+
+  def update
+    @review.update!(rating: params[:rating])
+
+    redirect_to subject_path(@review.subject)
+  end
+
+  def destroy
+    @review.destroy!
+
+    redirect_to subject_path(@review.subject)
+  end
+
+  private
+
+  def set_review
+    @review = current_user.reviews.find(params[:id])
+  end
+end

app/controllers/subjects_controller.rb

@@ -7,6 +7,8 @@ def index
   end
 
   def show
+    @user_review = current_user.reviews.find_by(subject:) if current_user
+
     respond_to do |format|
       format.html { subject }
     end

app/models/review.rb

@@ -0,0 +1,16 @@
+class Review < ApplicationRecord
+  belongs_to :user
+  belongs_to :subject
+
+  validates :user_id, uniqueness: { scope: :subject_id, message: "You can only review a subject once." }
+  validates :rating, presence: true, inclusion: { in: 1..5 }
+
+  after_commit :update_subject_rating, if: :saved_change_to_rating?
+  after_destroy :update_subject_rating
+
+  private
+
+  def update_subject_rating
+    subject.update_rating
+  end
+end

app/models/subject.rb

@@ -2,6 +2,7 @@ class Subject < ApplicationRecord
   has_one :course, -> { where is_exam: false }, class_name: 'Approvable', dependent: :destroy, inverse_of: :subject
   has_one :exam, -> { where is_exam: true }, class_name: 'Approvable', dependent: :destroy, inverse_of: :subject
   belongs_to :group, class_name: 'SubjectGroup', optional: true
+  has_many :reviews, dependent: :destroy
 
   validates :name, presence: true
   validates :credits, presence: true
@@ -47,5 +48,9 @@ def hidden_by_default?
     revalid? || inactive? || outside_montevideo? || extension_module?
   end
 
+  def update_rating
+    update(average_rating: reviews.average(:rating))
+  end
+
   delegate :available?, to: :course
 end

app/models/user.rb

@@ -5,6 +5,8 @@ class User < ApplicationRecord
 
   serialize :approvals, type: Array, coder: YAML
 
+  has_many :reviews, dependent: :destroy
+
   def self.from_omniauth(auth, cookie)
     # check that user with same email exists
     existing_user = User.find_by(email: auth.info.email)

app/views/subjects/_rating.html.erb

@@ -0,0 +1,33 @@
+<label class="mdc-deprecated-list-item">
+  Puntuación:
+  <div class="rating-container">
+    <div class="rating-item">
+      <button class="material-icons mdc-icon-button">star</button>
+      <%= @subject.average_rating.present? ? @subject.average_rating : "Sin calificar" %>
+    </div>
+    <% if current_user %>
+      <div class="rating-item">
+        <% for value in 1..5 %>
+          <% filled = @user_review.present? && @user_review.rating >= value %>
+          <% selected = @user_review.present? && @user_review.rating == value %>
+          <% url = selected || @user_review.present? ? review_path(@user_review) : reviews_path %>
+          <% method = selected ? :delete : (@user_review.present? ? :put : :post) %>
+          <%= form_with(url:, method:, local: true) do |f| %>
+            <%= f.hidden_field :subject_id, value: @subject.id %>
+            <%= f.hidden_field :rating, value: %>
+            <%= f.button filled ? 'star' : 'star_outline', class: "material-icons mdc-icon-button interactive-star" %>
+          <% end %>
+        <% end %>
+      </div>
+    <% else %>
+      <%= link_to new_user_session_path do %>
+        <div class="login-container">
+          Inicia sesión para calificar
+          <span class="material-symbols-outlined">
+            login
+          </span>
+        </div>
+      <% end %>
+    <% end %>
+  </div>
+</label>

app/views/subjects/show.html.erb

@@ -19,6 +19,8 @@
         Grupo: Desconocido
       <% end %>
     </label>
+
+    <%= render 'rating' %>
   </div>
   <hr class="mdc-deprecated-list-divider">
 

config/routes.rb

@@ -29,4 +29,5 @@
   resource :user_onboardings, only: :update
 
   resources :current_optional_subjects, only: :index
+  resources :reviews, only: [:create, :update, :destroy]
 end

db/migrate/20240305231624_create_reviews.rb

@@ -0,0 +1,13 @@
+class CreateReviews < ActiveRecord::Migration[7.1]
+  def change
+    create_table :reviews do |t|
+      t.references :user, null: false, foreign_key: true
+      t.references :subject, null: false, foreign_key: true
+      t.integer :rating
+
+      t.timestamps
+    end
+
+    add_index :reviews, [:user_id, :subject_id], unique: true
+  end
+end

db/migrate/20240316053425_add_average_rating_to_subjects.rb

@@ -0,0 +1,5 @@
+class AddAverageRatingToSubjects < ActiveRecord::Migration[7.1]
+  def change
+    add_column :subjects, :average_rating, :float
+  end
+end

spec/controllers/reviews_controller_spec.rb

@@ -0,0 +1,60 @@
+require 'rails_helper'
+
+RSpec.describe ReviewsController, type: :request do
+  let(:user) { create(:user) }
+  let(:subject) { create(:subject) }
+  let(:review) { create(:review, user: user, subject: subject) }
+
+  before do
+    # https://github.com/heartcombo/devise/issues/5705
+    Rails.application.reload_routes_unless_loaded
+  end
+
+  before do
+    sign_in user
+  end
+
+  describe 'POST #create' do
+    it 'creates a new review' do
+      expect {
+        post reviews_path, params: { subject_id: subject.id, rating: 5 }
+      }.to change(Review, :count).by(1)
+    end
+
+    it 'redirects to the subject page' do
+      post reviews_path, params: { subject_id: subject.id, rating: 5 }
+
+      expect(response).to redirect_to(subject_path(subject))
+    end
+  end
+
+  describe 'PATCH #update' do
+    it 'updates the review' do
+      patch review_path(review), params: { rating: 4 }
+
+      expect(review.reload.rating).to eq(4)
+    end
+
+    it 'redirects to the subject page' do
+      patch review_path(review), params: { rating: 4 }
+
+      expect(response).to redirect_to(subject_path(review.subject))
+    end
+  end
+
+  describe 'DELETE #destroy' do
+    it 'deletes the review' do
+      review
+
+      expect {
+        delete review_path(review)
+      }.to change(Review, :count).by(-1)
+    end
+
+    it 'redirects to the subject page' do
+      delete review_path(review)
+
+      expect(response).to redirect_to(subject_path(review.subject))
+    end
+  end
+end

spec/factories/reviews.rb

@@ -0,0 +1,7 @@
+FactoryBot.define do
+  factory :review do
+    user
+    subject
+    rating { 3 }
+  end
+end

spec/models/review_spec.rb

@@ -0,0 +1,49 @@
+require 'rails_helper'
+
+RSpec.describe Review, type: :model do
+  describe 'associations' do
+    it { is_expected.to belong_to(:user) }
+    it { is_expected.to belong_to(:subject) }
+  end
+
+  describe 'validations' do
+    subject { create :review }
+
+    it {
+      is_expected.to validate_uniqueness_of(:user_id)
+        .scoped_to(:subject_id)
+        .with_message("You can only review a subject once.")
+    }
+    it { is_expected.to validate_presence_of(:rating) }
+    it { is_expected.to validate_inclusion_of(:rating).in_range(1..5) }
+  end
+
+  describe 'callbacks' do
+    context 'calls update_rating on subject after commit' do
+      let(:review) { build :review }
+
+      it 'calls update_rating on subject after create' do
+        expect(review.subject).to receive(:update_rating)
+        review.save!
+      end
+
+      it 'calls update_rating on subject after update' do
+        review.save!
+        expect(review.subject).to receive(:update_rating)
+        review.update!(rating: 5)
+      end
+
+      it 'calls update_rating on subject after destroy' do
+        review.save!
+        expect(review.reload.subject).to receive(:update_rating)
+        review.destroy!
+      end
+
+      it 'does not call update_rating on subject if rating was not changed' do
+        review.save!
+        expect(review.subject).not_to receive(:update_rating)
+        review.update!(rating: review.rating)
+      end
+    end
+  end
+end

spec/models/subject_spec.rb

@@ -119,4 +119,25 @@
       expect(Subject.current_semester_optionals).to eq([s1])
     end
   end
+
+  describe '#update_rating' do
+    let(:subject) { create :subject }
+
+    context 'when there are no reviews' do
+      it 'updates average rating' do
+        subject.update_rating
+        expect(subject.average_rating).to eq(nil)
+      end
+    end
+
+    context 'when there are reviews' do
+      let!(:review) { create :review, subject: subject, rating: 5 }
+      let!(:another_review) { create :review, subject: subject, rating: 3 }
+
+      it 'updates average rating' do
+        subject.update_rating
+        expect(subject.average_rating).to eq(4)
+      end
+    end
+  end
 end

spec/rails_helper.rb

@@ -60,6 +60,8 @@
   config.filter_rails_from_backtrace!
   # arbitrary gems may also be filtered via:
   # config.filter_gems_from_backtrace("gem name")
+
+  config.include Devise::Test::IntegrationHelpers, type: :request
 end
 
 Shoulda::Matchers.configure do |config|