The right way to declare element attributes with TypeScript and React

Let's say you have a button component in your React application and you want to provide users with optional props that are available in common buttons like onClick. This is one way to do:

interface ButtonProps {
  onClick?: () => void

const Button: React.FC = function Button(props: ButtonProps) {
  return <button {...props}></button>

The problem with the approach above is that anything that isn't specified in the interface wouldn't be available, so if somebody wanted to use onMouseOver, it would error. One way to "solve" it is by adding every event that comes to your mind, but you would end up with dozens of extra lines.

The ideal solution is to extend the interface using ComponentProps, like below.

interface ButtonProps extends React.ComponentProps<'button'> {
  // custom props here
// the rest is identical

This way, your component now accepts everything a normal button would and you can still extend with your own custom props.