OLX Challenge - Phone Number Validator

South African mobile numbers validation.

Project overview

Motivation

Backend Engineer Assessment Exercise to perform validation of South African mobile numbers, provided through a CSV file.

Documentation

Project API Swagger file can be found here.

Quick Start

Running Locally

Database

This service requires access to a database. For that purpose, a docker-compose.yaml was included to allow for any dependency to be started locally, mainly a Postgres DB available at port 5432. To get them up-and running just run the up command on the root of the repository:

docker-compose up

Build

The build task will build the jar and run unit tests. To do so, simply run:

./gradlew clean build

Run

To run the application locally, default Spring profile can be used. Application properties sets the data source to the local database started with docker-compose, running at port 5432.

./gradlew clean bootRun

Usage

For usage details, check API documentation.

Design Decisions

Mainly due to time constrains which affected development of solution, mind the following implementation rationales and shortcomings/areas of improvement:

• Support libraries
  • Spring Boot + Web/Data/Test starters to help accelerate development.
  • Flyway DB migration tool to help define DDL/DB schemas.
• Number validation:
  • SA mobile number format validation was based on work by Warwick Chapman (URL).
  • Fixing of incorrect phone numbers was only based on quick analysis of provided dataset and assuming fixable values would be the ones with valid format plus a giving suffix (e.g. '27735405794_DELETED_1488987214').
• API implementation
  • No security implemented to restrict access to endpoints.
  • File validation issues (empty content, invalid mime type...) will abort upload process and return a BAD_REQUEST/400 HTTP error code.
  • More consistent error handling, including more fine grained definition of different error situations, is needed.
  • No listing/search functionality to get processed file results
  • Logging is missing
• Testing
  • Only a small number were tests were written, hence coverage is low. Main tests cover JPA repository functioning and phone number format validation (the core feature of the project).