cheatmenot/mynt-cost-api

Design

1. Simple RulesEngine com.example.myntcostapi.engine.RulesEngine implementation:
   • adding rules by creating java class which extends Rule com.example.myntcostapi.interfaces.Rule interface, and add it on Beans com.example.myntcostapi.configuration.Beans, take note that the order is defined when adding it.
   • removing rules by just remove it on Beans and you can also remove the java file
   • priority update on rules by just adjusting the order how rule will be added
   • update of condition and other stuff on rules can be achieved by updating in the specific rule implementation
   • (Future plans) - rules can be external or maybe some portion of it.
2. ControllerAdvice - this will handle all the exceptions and create error responses
3. Validation - validations on the request body
4. Dependency Injection - uses spring's dependency injection for auto initialization and dependency injection of classes

Testing

API URL

POST http://localhost:8080/api/v1/deliveryCost
{
    "weight": 49,
    "height": 10,
    "width": 10,
    "length": 10,
    "voucherCode": "MYNT"
}

Sample Responses:

1. Success with no voucher code

{
    "weight": 49.0,
    "volume": 1000.0,
    "cost": 980.0
}

2. Success with voucher code

{
    "weight": 49.0,
    "volume": 1000.0,
    "cost": 967.75,
    "originalCost": 980.0,
    "discount": 12.25,
    "discounted": true
}

3. Validation errors on fields

{
    "code": "VALIDATION_EXCEPTION",
    "message": "[width must not be null; length must not be null; weight must not be null; height must not be null]"
}

4. If weight field exceed 50

{
    "code": "RUNTIME_EXCEPTION",
    "message": "Rejected - Parcel exceed 50kgs"
}

5. Error on fetching from voucher client

{
    "code": "RUNTIME_EXCEPTION",
    "message": "Error on getting voucher details: I/O error on GET request for \"https://mynt-exam.mocklab.ioa/voucher/MYNT\": mynt-exam.mocklab.ioa; nested exception is java.net.UnknownHostException: mynt-exam.mocklab.ioa"
}

Unit Test

Haven't added it since it would take more time, but if you let me I am capable of doing unit testing in Mockito and Powermock