This little 2D drawing application is the result of some frustration with React and (unit) testing applications built in it.
It uses the ideas from the book "Grokking Simplicity" to extract all interesting behaviour / logic / business rules / pick-your-fancy-word into pure functions (called calculations in the book) which are called from 'shallow'/'skeletonal' actions in the UI code (the React code).
It's written in typescript.
Use mouse left-clicks to draw rectangles on canvas!
npm install
npm start
npm test