- You need to have the latest version of Node. Preferably, you're using 9.8.0, but the latest LTS should work as well.
- You should have
npx
installed usingnpm install -g npx
. - Install the React Developer Tools.
All libraries have subtle rules that you have to follow for them to work well. Often these are implied and undocumented rules that you have to learn as you go. This is an attempt to document the rules of React renders. Ideally a type system could enforce it.
A number of methods in React are assumed to be "pure".
On classes that's the constructor, getDerivedStateFromProps, shouldComponentUpdate and render.