A simple RESTful API designed to collect and store location information using PostgreSQL

See the getting started

We want to design a system that can tell us the distance between our location and some other locations which we expect to be supplied to us.

Design a RESTful API which can collect the information on the different locations for us and also determine the distance between the locations and a configurable location which can be changed or supplied. The formula for calculating distance between two points can be gotten here https://en.wikipedia.org/wiki/Great-circle_distance.

Define a set of data models that include:

A location entity with at least the following structure, you can add more to it at your discretion

• Id
• Location name
• Description
• Website (Optional)
• Phone
• Contact Person
• Coordinates

You can make use of any database but we recommend PostgreSQL.

The following RESTful API must be implemented

• Create new location
• Edit Location
• Delete Location
• Fetch All Locations
• Fetch Specific Location
• Calculate distance

This task should be completed using

• NestJs Framework
• The data model should also be defined using Grpc (This is optional but using it will earn you extra points)
• An ORM like Type ORM can also be used

Clone this repo from git bash or GitHub desktop or you can just fork it and clone your forked copy to your development machine.

git clone [email protected]:calebpitan/autochek-assessment.git

# or fork it to have a copy and clone

git clone [email protected]:<username>/autochek-assessment.git

When done with cloning switch to the new autochek-assessment folder in the directory you cloned into

cd autochek-assessment

Install dependencies using Yarn

yarn install

Before starting the server make sure you have PostgreSQL installed and also PostGIS. You can install PostGIS using the stackbulilder application that comes with the PostgreSQL server you just installed (check your installation directory). You can checkout this tutorial that shows how to install PostGIS using stackbuilder.

I used PostGIS to store location coordinates (latitude and longitude), which stores it in a very efficient data format that doesn't come out of the box with the PostgreSQL application.

You can learn more about PostGIS.

When all this necessary installations are complete, make sure your PostgreSQL server is running as a background service (or at least running).

yarn start:dev

There's an .env.example file in this repo that exposes the ENV_VARS required to run this application. They are to be created into an .env file in the same directory as the .env.example with actual values.

• PORT: the application port (e.g, 5000)
• PG_HOST: the host on which the database is running (e.g, localhost)
• PG_PORT: the port on which the databse is listening (e.g, 5432)
• PG_USER: the database user (e.g, 'postgres')
• PG_PASSWORD: the database user's password (e.g, 'root')
• PG_DATABASE: the name of the database to use (e.g, autochek_assessment). If this database doesn't exit, you should create it first.

Returns a list of all found location

• query
  • limit (number) - the amount of results to be returned
  • offset (number) - the amount records to skip before starting to select records

curl http://localhost:5000/location

• response

  {
    "data": {
      "location": [
        {
          "id": 1,
          "location_name": "Lagos",
          "description": "Lagos in Nigeria",
          "website": "https://www.lagos.ng",
          "phone": "07066001122",
          "contact_person": "Jide Sanwolu",
          "coordinates": {
            "type": "Point",
            "coordinates": [6.4550575, 3.3941795]
          }
        },
        {
          "id": 2,
          "location_name": "Abuja",
          "description": "Abuja in Nigeria",
          "website": "https://www.abuja.ng",
          "phone": "07088001122",
          "contact_person": "Office of the President",
          "coordinates": {
            "type": "Point",
            "coordinates": [9.4550575, 4.3941795]
          }
        }
      ]
    }
  }

Returns a list of all found location

curl http://localhost:5000/location/1

• response

  {
    "data": {
      "location": {
        "id": 1,
        "location_name": "Lagos",
        "description": "Lagos in Nigeria",
        "website": "https://www.lagos.ng",
        "phone": "07066001122",
        "contact_person": "Jide Sanwolu",
        "coordinates": {
          "type": "Point",
          "coordinates": [6.4550575, 3.3941795]
        }
      }
    }
  }

Creates a new location

curl -d '{ "location_name": "Lagos", "description": "Lagos in Nigeria", "website": "https://www.lagos.ng", "phone": "07066001122", "contact_person": "Jide Sanwolu", "coordinates": [ 6.4550575, 3.3941795 ] }' -X POST http://localhost:5000/location

• response

  {
    "data": {
      "location": {
        "id": 1,
        "location_name": "Lagos",
        "description": "Lagos in Nigeria",
        "website": "https://www.lagos.ng",
        "phone": "07066001122",
        "contact_person": "Jide Sanwolu",
        "coordinates": {
          "type": "Point",
          "coordinates": [6.4550575, 3.3941795]
        }
      },
      "message": "...",
      "success": true
    }
  }

Updates a location found by its id

curl -d '{ "contact_person": "Raji Fashola" }' -X PUT http://localhost:5000/location/1

• response

  {
    "data": {
      "location": {
        "id": 1,
        "location_name": "Lagos",
        "description": "Lagos in Nigeria",
        "website": "https://www.lagos.ng",
        "phone": "07066001122",
        "contact_person": "Raji Fashola",
        "coordinates": {
          "type": "Point",
          "coordinates": [6.4550575, 3.3941795]
        }
      },
      "message": "...",
      "success": true
    }
  }

Deletes a location found by its id

curl -X DELETE http://localhost:5000/location/1

• response

  {
    "data": {
      "id": 1
    },
    "message": "...",
    "success": true
  }

Get the great circle distance between two locations

• query
  • loc_1 (string) - the latitued and longitudes separated by a comma
  • loc_2 (string) - the latitued and longitudes separated by a comma

curl -X GET http://localhost:5000/location/distance?loc_1=6.4550575,3.3941795&loc_2=9.4550575,5.3941795

• response

  {
    "data": {
      "location": {
        "distance": 399721.083,
        "unit": "meter"
      }
    }
  }