Turno, formerly TurnboverBnB - BnbBank Test

This is a test proposed by Turno to build a simplified Bank System using PHP/Laravel and ReactJS.

Original Test Repository https://github.com/TidyDaily/developer-test/tree/main

Application: https://bnb-bank.andreciornavei.com.br

This project contains the entire application splitted in folders/subprojects (frontend, backend and docs) and make use of GitHub Pipeline CI to deploy each subproject as needed.

Still, AWS infrastructure is being used to release the project and all its resources is provisioned by IaC using serverless framework on each subproject (backend/frontend) folders.

MongoDB is being used for database.

Requirements met

Application stories requirements

Customer

• ✅ A user can create a new account with username and password
• ✅ A user starts with 0 balance
• ✅ A user can deposit more money to his account by uploading a picture of a check and entering the amount of the check. if the check is approved by an admin, the money is added to the bank account.
• ✅ To buy something, the user enters the amount and description; a user can only buy something if she has enough money to cover the cost.
• ✅ A user can see a list of balance changes including time and description.

Admin

• ✅ An admin account is already created with a hard coded username and password.
• ✅ An admin can see a list of pending check deposit pictures with amount and picture and click to approve or deny the deposit.

Simplifying Assumptions

• ✅ An admin can’t be also a customer

Backend requirements

• ✅ Automated Tests / Test Coverage
• ✅ API Access Control (Policies, Gates, etc.)
• • In addition to the Authenticate middleware, was created two new middlewares to handle user role policies, where them its attached to the correct routes for each role.
• ✅ Implement a design pattern (DDD, Repository Pattern, etc.)
• • With special attention on backend/app/Domain and backend/app/Infrastructure. Them follow the SOLID principles and implements the Clean Architecture;
• • Domain Usecases always expects an interface of an implementation. Thats implementations is Injected by Controllers.
• • Infrastructure folder implements the data access for repositories and providers;
• ✅ Make a good and cohesive database design

Frontend requirements

• ✅ TypeScript
• ✅ Front-end cache
• • The frontend is cached using CloudFront. Always a deploy happens, the cloudfront cache is invalidated by CI.
• ✅ Code structure and organization
• • Give an special attention to page structure, each page contains a conjunction of (context, controller, view, types, styles & index) files, where each one has its own responsability, improving readability;
• ✅ Performance and monitoring tools
• • Was made use of package use-context-selector that improves the context providing. Also, for specific cases, was created an isolated component that inherit neededs data thought context, avoiding the re-render of entire screen.

Stategic Decisions

1 - Docker + Bref (https://bref.sh/docs/deploy/docker)

Small applications does not need to consume paid services on AWS, in this case, the API was packaged on a Docker Image and deployed inside a Lambda Function with help of Bref, so the API will always be available for anyone who try to dispach a request against it, and of corse, using the Always Free Tier limit.

2 - Uploads with AWS Presigned Url

Backend applications should not have to handle hard proccess like uploads, it could use a lot of cpu, memory and time, for that, was used uploads with presigned urls, where the backend just ask to AWS for a URL where upload can be made.

3 - AWS S3 Bucket LifecycleConfiguration

./backend/serverless -> resources.Resources.UploadBucket

As users can abort deposit operations at any moment, it is important to remove temporary check uploads from bucket. For that, all temporary uploads are made on ./tmp folder on bucket, it contains a LifecycleConfiguration to remove the file in 24h. Once the deposit operation is finished successfully, the check file is moved from .tmp/ to ./deposits folder, where it will not be deleted anymore.

Localhost Commands

Backend

For short commands on backend, it is using the backend/package.json to store scripts, where you can execute some usually commands.

cd backend
yarn test # to run unit tests on application
yarn develop # to execute application in development mode
yarn migrate # to run initial seed migrations