internal-transfers-api

A REST API for money transfers between accounts.

Built With

• Kotlin
• Ktor - Web Framework
• Gradle - Build Tool

Other libraries used

• Koin - Dependency Injection Framework
• JaCoCo - code coverage
• hibernate-validator - request validation
• JUnit5 - testing
• kotlinx-coroutines-core - validating/testing concurrency
• mockito - mocking in tests
• assertJ - assertions in tests
• gson - json parser for tests

Running on local

Building

Run the below command on terminal to build the jar:

./gradlew clean build

A fat-jar will be created in location ./build/libs/internal-transfers-api-1.0.0-all.jar

Running

Once you have built the jar using above step, you can start the application by any of the below commands:

Gradle Command

./gradlew run

Direct Command

java -jar ./build/libs/internal-transfers-api-1.0.0-all.jar

Running on Docker

Make sure docker is running on your machine and then trigger the docker.sh script located in the resources/scripts path.

./resources/scripts/docker.sh

The above script will run the application on post 8090 and will also run the swagger-ui docker container for api-spec on port 8091.

Testing and Reports

Run the below command on terminal to test the application and generate a test report and a JaCoCo code coverage report:

./gradlew clean test

Test reports can be found at ./build/reports/tests/test/index.html

Code Coverage reports can be found at ./build/reports/jacoco/test/html/index.html

Available Endpoints

This api doesn't have a Swagger/OpenAPI integration because of the lack of an official/cleaner OpenAPI support for Ktor Framework.

OpenAPI spec for this service is available under docs directory in api-spec.yml file. Also, the available end-points information has been added below.

Account Endpoints

1) Get All Accounts

GET localhost:8090/accounts - Returns all the accounts available. (For the ease of testability, I have created 10 random accounts already)

Sample Request

curl --request GET \
  --url http://localhost:8090/accounts

Sample Response

[
    {
        "id": "833fb7f0-9549-4dbd-b570-2d9e4be2b0ef",
        "balance": 605.43
    },
    {
        "id": "89861c9e-5ca8-4814-a5c0-a284ea23d9e3",
        "balance": 86.84
    }
]

2) Create Account

POST localhost:8090/accounts - Creates a new account.

Sample Request

curl --request POST \
  --url http://localhost:8090/accounts \
  --header 'content-type: application/json' \
  --data '{
    "balance": "123"
}'

Sample Response

{
    "id": "3c8754aa-6fbe-4b72-ad08-dcbf29501ea3",
    "balance": 123
}

Internal Transfer Endpoints

1) Transfer Money

POST localhost:8090/internal/transfer/ - Transfers Money from one account to another

Sample Request

curl --request POST \
  --url http://localhost:8090/internal/transfer/ \
  --header 'content-type: application/json' \
  --data '{
    "senderAccountId": "833fb7f0-9549-4dbd-b570-2d9e4be2b0ef",
    "receiverAccountId": "3c8754aa-6fbe-4b72-ad08-dcbf29501ea3",
    "amount": 12
}'

Sample Response

No json response for this endpoint, just HTTP status gets returned.