novinary / kiwi-t9

Kiwi.com full-stack task (React Native, NodeJS)

Kiwi T9

Assignment

Implement a number to word list converter as a Node backend and React fronted. The backend should provide a rest endpoint that converts a given numeric string into a list of corresponding words in the style of T9 or Phonewords. For example, given the input 23 the output should be: ad, ae, af, bd, be, bf, cd, ce, cf The frontend should allow the user to enter a number, query the backend for the corresponding expansions, and display them.

The solution should be shared with us in a git repository with real history included. It's OK not to deliver 100%, but the more working parts the better. For example if you struggle with the backend, focus on frontend and just mock the API calls.

Take this task as a chance to present your skills. If you are good in UI, let us see that. If you are more into the backend, it's OK to have simple FE.

If you know what tests are for, don't keep it for yourself, show it in the code.

Ways to go beyond the minimal solution could include for example:

• phone keyboard -like UI
• great project setup
• mobile app in React Native
• filtering to include only real words based on a suitable word list

The task should contain unit tests.

Demo

Installation and run

Prerequisites

Install:

• NodeJS: https://nodejs.org
• Expo: https://docs.expo.io/versions/v30.0.0/introduction/installation
• Yarn: https://yarnpkg.com/lang/en/docs/install/#mac-stable

Clone repository:

git clone https://github.com/jvaclavik/kiwi-t9
cd kiwi-t9

Install Server

cd server       # List proper directory
yarn            # Install dependencies
yarn start      # Start NodeJS server

Server will run on: http://localhost:3000

Install Client

cd client       # List proper directory
yarn            # Install dependencies
expo start      # Start Expo

Scan QR code or click on Run on iOS simulator

Project structure

• Server is based on NodeJS, Express, Nodemon and Supertest
• Client is a mobile app based on React Native, Expo, Jest and Flow.

├── README.md
├── client
│   ├── App.js              # Mobile app entry point
│   ├── app.json            # Expo app configuration
│   ├── assets              # Icon and Splash screen assets
│   ├── package.json
│   ├── src                 # Mobile app source code
│   │   ├── components      # Components
│   │   ├── config          # Basic app configs
│   │   ├── containers      # Contains RootContainer (main screen)
│   │   ├── services        # Defines API
│   │   ├── themes          # Defines colors, metrics and fonts
│   │   ├── types
│   │   └── utils           # Component independent utils
│   └── yarn.lock
├── demo.gif
└── server
    ├── __tests__
    ├── app.js              # Server entry point
    ├── bin
    ├── package.json
    ├── public
    ├── routes              # Defines routes and main logic
    ├── utils               # Custom utils
    ├── views
    └── yarn.lock

Testing

Run server tests

cd server
yarn test

Run client tests

cd client
yarn test

API docs

Words [/words]

Retrieve words [GET]

Retrieves words based on T9 number combination.

• Parameters
  • input: (number) - T9 number combination (^[23456789]{1,11}$)

• Response 200 (application/json)

  • Body

        [
            "ad",
            "ae",
            "af",
            "bd",
            "be",
            "bf",
            "cd",
            "ce",
            "cf"
        ]
    

• Response 400 (application/json)

  • Body

        {
            "errors": [
                "Bad input. Allowed pattern is: ^[23456789]{1,11}$"
            ]
        }
    

• Response 400 (application/json)

  • Body

        {
            "errors": [
                "No input."
            ]
        }
    

Future improvements

• Use real word dictionary
• Use frequency analysis to mark proper word relevance
• Solve upper case characters, diacritic and special characters
• Think about better UX
• Test app on Android phones