This project was built using:

• Debian GNU/Linux 12 (bookworm)
• PostgreSQL v15.13
• Ruby v3.2.2
• Ruby on Rails v8.0.2
• Node v22.13.0

Download this repository into your local computer.

git clone https://github.com/KarlHeitmann/task_management_system

Open a terminal and navigate to the backend folder:

cd library_management_system_backend/

Install dependencies:

bundle install

Create, migrate and seed the database:

bundle exec rails db:create
bundle exec rails db:migrate; RAILS_ENV=test bundle exec rails db:migrate
bundle exec rails db:seed

NOTE: you need to setup the jwt_secret value. Run this command in your terminal:

bundle exec rails secret

Copy the output string into your clipboard, run this command:

bin/rails credentials:edit

And add the key-value pair in your editor

jwt_secret: <your random generated secret>

Save and exit, you're ready to continue

NOTE you may have notices I use bundle exec, I have it aliased to be command so it is not long to type. I've seen people often use bin/rails, but I have not seen any problems with this old fashioned method.

bundle exec rspec spec

You should see everything is OK. Now it is time to run the rails server

bundle exec rails server

Backend server is up and running on port 3000

Pro tip: use nvm to manage your node versions like me :)

Open a terminal and navigate to the frontend folder:

cd library_management_system_only_react/

Install dependencies

npm install

Run the project

npx nx dev library_management_system_only_react

Frontend development server is up and running on port 4200

Visit http://localhost:4200/ on your web browser. If you run into any errors, just refresh the page. It may be a cookie it is bothering. The credentials are:

• To login as a member: email: "[email protected]", password: "asdasd"
• To login as a librarian: email: "[email protected]", password: "asdasd" NOTE: You can corroborate it by viewing the credentials inside the seed file: library_management_system_backend/db/seeds.rb, line 12 and 15

The frontend don't use any router at all. Is everything literally built into a single page app, with all the specifications written in the exercice. I think the seeded data and the web interface makes the application very intuitive. If you log in as a member or as a librarian you will see the member or librarian dashboard with the lists and stats written on the specs at the top of the page. Both types of users will see a books list below.

Members will have all buttons disabled, they will only be able to borrow a book from the list. Librarians will have all CRUD actions enabled, they will have disabled the "borrow" buttons, but they will have enable the "return" button for the books they can return.

The first days of the challenge I was struggling with authorization: should I use omniauth? Or devise? I attempted to do something, but there were a lot of decisions to made. I think they are beyond the scope of this exercise. So I dropped this approach and decided to go with a simple encrypted Bearer token on the header. I know this is very insecure, but the instructions don't say anything about security. However, this insecure method is useful to show the way I fix the authorization problems by myself.

The philosophy behind all this exercise is: use as few dependencies as possible.

About the tests, I'd have liked to have had time to do tests on Cypress. Sadly, it was not possible to do. I don't have any tests at all for the frontend. But the backend is well tested.

My books_controller is very important for the application, it does a lot of things, and it is responsible to call the right methods to borrow and return books depending on whether the user is a member or a librarian. That's the reason its corresponding test file: library_management_system_backend/spec/requests/books_spec.rb has nearly 500 lines. This test file contains shared examples, and simulates requests done by members, librarians and anonymous people.

I have followed a "fractal" approach to develop the frontend code. By inspecting the code, you'll discover the codebase not only grows vertically (in number of files), but it grows horizontally: it has folders and nested folders. You can know more about this fractal approach by reading this article I wrote on an old blog entry of my blog

TODO: Right now I don't have much time left, but if possible I will record a screencast doing a walkthrough of the app and will paste the link here.