React Offline Test

TLDR

This README describes the test - read it
Everything you need to know is in this readme
Definitely read the 'What are you looking for in the solution?' bit

What is this?

We ask our JavaScript candidates to take this test as part of our recruitment process. This is step one. If we like your submission we will invite you in for (probably one) technical interview where we will have a chat and ask you to do some pair programming.

What should it do?

Your task is to write a React application that displays the current mix of energy generation in the UK (i.e. how much nuclear, wind, solar etc.).

We have provided an empty React app to get you started - it is pre-configured with Babel and Webpack to get you up and running with no fuss. Details of an API that you can call to load the data that you should display are provided below.

How should it work?

Definitely using React!

How you decide to load and show the data is entirely up to you. You are free to use any libraries that you want (via npm) and you can choose how you wish to display the data. Some suggestions are:

Huge numbers
Tiled icons and numbers
A chart of some kind
Relative sized colour bands in a giant unicorn's rainbow puke

Getting started

If you haven't already, fork our GitHub project
Get the dependencies - npm install
Run the app - npm start - it will be available at http://localhost:8080
Write your code, starting with app.tsx

Where can I find the UK energy generation data?

Here: https://api.carbonintensity.org.uk/generation

An example response is in example_api_response.json, where you can see that the data includes the relative percentage values of a variety of fuels for 1 settlement period (half hour block). A live call to the API will give you the data for the latest complete settlement period. This is absolutely fine for the purposes of this test - you do not need to worry about any larger time periods.

An existing website that shows this data is here: https://gridwatch.co.uk/

What are you looking for in the solution?

A simple, readable, well-factored solution - not the fanciest charting library or middleware components you can find
Automated tests
Some form of visual styling - we don't care what technology you use for this but an un-styled ul is not going to cut it

Anything else I should know?

You can use any JavaScript features
You can use TypeScript if you prefer (the project is already configured for this)
You can use any libraries that you want
npm start will start a Webpack hot-reload dev server so you can make live changes
We really like TDD
We like TypeScript too
We like simplicity - a more complicated solution is rarely better than a simple one
Some types of chart seem like a really obvious fit but are not actually very good at showing small values in a data set

Finishing

If you have made any changes that require us to do more than just an npm install and npm start to run your solution then please make this clear in the readme
Let your agent know that you're done and we will take a look at your fork in GitHub (no pull requests please)

anthonyrenard / react-offline-test