Setup Code

1. Create .env from .env-example file and provide your database connection string. e.g: DATABASE_URL=postgres://postgres:password@localhost:5432/dbname
2. Run below command

npm init

This will create tables and fill the data in it.

npm server

This will run experss server on http://localhost:4000

npm start

Start server on production.

Application use

Overview

The primary REST service for a "Subscription as a Service" startup. REST service will be used by companies that will define subscriptions plans to which the users of the platform can subscribe to.

API Service

The primary aspect of this programming challenge is to implement the following two APIs:

/user
/subscription

The details of each of these APIs are as follows:

/user

This is a simple CRUD API that adds a user to DB.

PUT /user/

creates a user with specified username in the DB.

Sample Input: PUT /user/jay Required Output: Just a HTTP status: 200 on success, other appropriate code for failures

GET /user/< username>

Sample Input: GET /user/jay

Sample Output:

{
"user\_name": "jay",
"created\_at": "2020-02-29 19:30:00"
}

/subscription

This is the primary API being tested in this challenge.
This will need to provide mechanisms to:
Register a new subscription for an existing user, with a specified plan and
start date

POST /subscription/

Inputs:

{
"username": < username >,
"planId": < planId >,
"startDate": < date in YYYY-MM-DD format >
}

Sample Input

{ "userName": "jay", "planId": "PRO_1M", "startDate": "2020-03-03" }

Expected Output:

{ "status": <["SUCCESS"|"FAILIURE"]>, "amount": <+/- amount
credited/debited> }

Sample Output:

{ "status": "SUCCESS", "amount": -200.0 }

Additional Details

On success, return 2 00 HTTP status. For failures, pick an appropriate HTTP code.
The timestamp indicates the start date for the new plan, and it will be valid for the
number of days shown in the table below
planId can be one of those listed in the table below:

GET /subscription/< username >/< date >

Sample Input: /subscription/jay/2020-02-01

Note that the date in the above is optional: /subscription/jay

Expected Output:

When input date is specified

planId that will be active for user at specified date.
Number of days left in plan from the specified input date
Sample output
{ "planId": "PRO_1M", "daysLeft": 3 }

When input date is NOT specified

List all subscription entries available in database for user with start and valid
till dates.

Sample output

[
  {
    "planId": "TRIAL",
    "start_date": "2020-02-22",
    "valid_till": "2020-02-28"
  },
  {
    "planId": "PRO_1M",
    "start_date": "2020-02-29",
    "valid_till": "2020-03-30"
  }
]