EasyGeneratorAssignment

Easy Generator Assignment

Setup

Solution

The solution is a full stack web application which utilizes docker for containerization, NestJS for backend, MongoDB for database, React with Vite as frontend and Nginx as web server.

The API documentation can be found at Swaggerdocs

/auth/signup
requires username, name and password

/auth/signin
requires username and password

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Database structure

User Table : To store the user infomation

Column	Type	Description	Constraints
username	String	Unique username of the user.	Required, Unique
name	String	Full name of the user.	Required
password	String	Hashed password for the user.	Required

UserSession Table: To store the session level information

Column	Type	Description	Constraints
username	String	Username associated with the session.	Required
token	String	Unique token for the session.	Required, Unique
createdAt	Date	Timestamp when the session was created.	Required, Default: Current Time
updatedAt	Date	Timestamp when the session was last updated.	Required, Default: Current Time
expireAfterSeconds	Integer	Time-to-live (TTL) index on updatedAt for automatic expiration.	Expires 1 hour after updatedAt

Database Considerations

1. Unique index to disallow duplicates
2. Session table incase we want to have multi device login, we can manage sessions to renew etc seperately.
3. TTL ensures that session information i.e. token is deleted once used

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Backend Considerations

1. Input validation is added to minimize errors
2. Nestjs Rate limiting is being used to enable ratelimiting for apis. Currently, its in memory, but we have the provision to plugin a persistence strategy for it.
3. Logging has been implemented to track activity

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Frontend

Frontend is built in react and vite and nextui. The boilerplate has been obtained from nextui-cli

For state management we have used Zustand as its a lightweight library for state management.

Sign Up

Log In

Logout

Frontend Considerations

1. We have created only 2 pages one for auth and one for index
2. By default if user is not loggedin they will be redirected to auth screen to signin/signup
3. If user is logged in then they won't be directed to sigin/signup directly to home page
4. Once logged in state is maintained to reuse in application

How to run

The application is dockerized, simply clone and run the following command in root

docker-compose up --build

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Limitations and todos

Due to time constraints we have some limitations for the application

1. Logout api is not created due to which we don't destroy session on backend.
2. The reason for maintaining session is that when we get a jwt token to validate, in addition to checking its signature we also need to check if its a valid token via db. This is because in a scenario, we logout the user, the jwt in theory will be active till its ttl, which can be misused, thus we need to check in db as well. Optimizations would include checking before ttl and keeping ttl in db to remove expired tokens.
3. Code coverage can be improve only basic tests are considered.
4. Salt for hashing the passwords can be implemented, currently we only have length based one-way hash
5. urc based logs, currently we are having basic logs, we can enhance to improve logs by passing unique reference code from request header