khomohzie / demo-credit

This is the API and backend server for the Demo Credit mobile application.

• Application Name: demo-credit
• Start Date: January 2nd, 2023

About

Demo Credit is a mobile lending app that features a wallet functionality. Borrowers can use their wallet to receive the loans they have been granted and also send the money for repayments.

Summary

Demo Credit is a mobile lending app that requires wallet functionality. This is needed as borrowers need a wallet to receive the loans they have been granted and also send the money for repayments.

This proposes an MVP (Minimum viable product) wallet service:

1. A user can create an account
2. A user can fund their account
3. A user can transfer funds to another user’s account
4. A user can withdraw funds from their account.

Backend setup

• Clone this repo git clone https://github.com/khomohzie/demo-credit.git
• Install dependencies yarn
• Create .env with your values. Check .env.sample for more information.
• Run MySQL server.
• Run Redis server locally. You can also configure it to use cloud. To use cloud, use process.env.NODE_ENV === 'production' or refer to redis configuration for more information.
• Migrate the database npm run migrate.
• Run seed files npm run seed (optional for development but necessary to run tests).
• Start server with yarn run dev or npm run dev
• Server will be running on http://localhost:4000 or otherwise as configured in your .env file.

E-R Diagram

https://dbdesigner.page.link/vQmhAkVMzdGntF558

Edit configurations (Optional)

Knex configuration

• Path to knex configuration - src/config/knex.config.ts
• To create migration file npx knex migrate:make <file-name> --knexfile ./src/config/knex.config.ts
• To run migration npm run migrate
• To rollback migration npm run rollback
• To run seedfiles npm run seed

• Note: You do not need to edit the src/config/db.ts file. You may only refer to it for understanding.
• Migrations and seeds are saved in src/db/migrations and src/db/seeds respectively.

Redis configuration

If you so desire to change the default configuration for the various environments e.g development to use cloud redis instead, refer to src/utils/redis.util.ts file and change:

const redisClient: redis.RedisClientType =
	process.env.NODE_ENV === "development"
		? redis.createClient()
		: process.env.NODE_ENV === "test"
		? redis.createClient()
		: redis.createClient({ url: process.env.REDIS_URL });

to

const redisClient: redis.RedisClientType =
	process.env.NODE_ENV === "development"
		? redis.createClient({ url: process.env.REDIS_URL })
		: process.env.NODE_ENV === "test"
		? redis.createClient()
		: redis.createClient({ url: process.env.REDIS_URL });

Tests

Before running tests, ensure the following:

1. NODE_ENV=test is present in your environment variables. Change from development or production to test.
2. Redis is started and running locally or on the cloud. If using cloud, refer to redis configuration to edit the configuration for test environments.

  npm run test

• Note: I specified the order of test files in the __tests__/index.test.ts file. All other *.test.ts files are ignored except start.test.ts. This is because succeeding tests need preceding tests to pass.

Error codes

1. • code: ACC_ERR_01
   • alias: acc_not_found
   • reason: account not found
2. • code: ACC_ERR_02
   • alias: acc_not_verified
   • reason: account not verified
3. • code: ACC_ERR_03
   • alias: acc_not_admin
   • reason: account not admin
4. • code: ACC_ERR_05
   • alias: wall_not_found
   • reason: id not associated with any wallet