This is a Next.js project bootstrapped with create-next-app.

Getting Started

First, run the development server:

npm run dev
# or
yarn dev
# or
pnpm dev

Open http://localhost:3000 with your browser to see the result.

Or go to https://waterfall-chart.vercel.app/

Approach

1. Determine how to fetch the data.

   • getStaticProps is used to fetch the data before the page is rendered.
   • The data is converted to a string, then parsed using react-papaparse. The data returned is an array of arrays.

2. Process the data by building an object for each item.

   • This returns useful information for each piece of data.
   • The buildDataObj calculates the cumulative and previous values for the cost and carbon intensity. These values are used to create a waterfall effect later in the BarChart.
   • getTotal calculates the final total for OPEX and CAPEX subcategories. The object returned from getTotal is pushed into the _obj placeholder array. The _obj array is returned from buildDataObj.

3. Build the UI using Material UI and the bar graph using Recharts

   • The Radio groups and element groupings use Material UI to display the options.
   • The Bar Chart is used to create the waterfall effect using the cumulative and previous values for the cost and carbon intensity.
   • Options and WaterfallChart are the main components.

4. Assumptions:

   • As noted in the instructions, Cost and Carbon Intensity may be changed or other fields are added in the future. In the interest of time, the code assumes only Cost and Carbon Intensity are the only options available. Further refactoring would be required if other options are added.

Time spent

> 5 hours because I thought this was a fun and interesting challenge. I used this as an opportunity to learn a bit about waterfall charts and using Recharts.