This repository includes the implementation of Yape Code Challenge (instructions here), that consists on a GraphQL API that manages Transactions and a Anti-Fraud service used to validate all created Transactions.

• Typescript
• Node.js + Express.js
• Prisma ORM + Postgres
• Kafka
• GraphQL
• Docker

The project structure is organized in the following directories:

.
├── anti-fraud-service      # Anti-Fraud Express app
    ├── src                 # Source files of the solution
    └── test                # Tests for solution services
├── transactions-service    # Transactions Express app
    ├── src                 # Source files of the solution
    ├── prisma              # Prisma ORM schema definition and migrations
    └── test                # Tests for solution services
├── .gitignore
├── docker-compose.yml
└── README.md

The project has 2 main environment variables:

KAFKA_HOST_URL   # Host where the Kafka cluster is running
DATABASE_URL     # Postgres SQL database connection url

Here we could find guides to test, build and execute the solution.

In order to run the project unit tests, we first need to go to transactions-service directory.

cd transactions-service

Then, we need to install the project's dependencies.

yarn install 
# or
npm install

Finally, to execute the unit test we run:

yarn test
# or
npm test

Tests run will be shown on CLI and a jest coverage report will be displayed and saved on a coverage directory.

We would follow the same steps to run the unit tests from the Anti-Fraud service, but this time with the anti-fraud-service directory.

cd anti-fraud-service
yarn install  or  npm install
yarn test  or  npm test

In order to generate a deployment ready build, we would follow the next steps for both applications:

cd transactions-service
#or
cd anti-fraud-service

Then, we need to install the project's dependencies.

yarn install 
# or
npm install

Finally, to create the build run the following command:

yarn build
# or
npm build

This will first execute the following steps:

• Run project's tests
• Create a Typescript build using the tsconfig.build.json file
• Copy the GraphQL schema file to dist folder using copyfiles package (Only for transactions-service)

Before starting the execution process:

• Make sure that you have docker already installed (it could be docker-desktop or docker-engine).
• Make sure you have docker Compose plugin installed (install compose-plugin). IMPORTANT: If you have a docker-desktop installation, the Compose plugin is already included.

First, we need to be on project root directory. There, we need to run the following command to build the services specified on the docker-compose.yml file:

docker compose -f "docker-compose.yml" up -d --build 

The compose file will create and run the following:

- Zookeeper             (PORT:'2182')
- Kafka cluster         (PORT:'9092')
- Postgres DB           (PORT:'5432', USER:'postgres', PASSWORD:'postgres')
- PgAdmin               (PORT:'5050', EMAIL:'[email protected]', PASSWORD:'root')
- Transactions Service  (PORT:'3000')
- Anti-Fraud Service    (PORT:'3005')

The file will also create a service that would be in charge of creating the needed topics for producers and consumers communication

After the execution is completed, there is one last step to start using the application. We will call a seed function to populate the Transaction Type table with some pre-defined values:

yarn prisma db seed
# or
npm prisma db seed

This seed will create the following rows:

[
  { id: 1, name: 'Transaction 1' },
  { id: 2, name: 'Transaction 2' },
  { id: 3, name: 'Transaction 3' }
]

Now you can go to the Transaction Service GraphQL Playground to start using the app.

• Stop all the services

docker compose -f "docker-compose.yml" down 

• Restart all the services (It would execute down and up sequentially)

docker compose -f "docker-compose.yml" down 
docker compose -f "docker-compose.yml" up -d --build 

A ready-to-use playground is created for the transactions-service on the /graphql endpoint.

Documentation of schema, queries and mutations can also be found inside the playground.