ReactJs: What should the PropTypes be for this.props.children?

Try something like this utilizing oneOfType or PropTypes.node

import PropTypes from 'prop-types'...static propTypes = {    children: PropTypes.oneOfType([        PropTypes.arrayOf(PropTypes.node),        PropTypes.node    ]).isRequired}

or

static propTypes = {    children: PropTypes.node.isRequired,}

For me it depends on the component. If you know what you need it to be populated with then you should try to specify exclusively, or multiple types using:

PropTypes.oneOfType 

If you want to refer to a React component then you will be looking for

PropTypes.element

Although,

PropTypes.node

describes anything that can be rendered - strings, numbers, elements or an array of these things. If this suits you then this is the way.

With very generic components, who can have many types of children, you can also use the below - though bare in mind that eslint and ts may not be happy with this lack of specificity:

PropTypes.any

The PropTypes documentation has the following

// Anything that can be rendered: numbers, strings, elements or an array// (or fragment) containing these types.optionalNode: PropTypes.node,

So, you can use PropTypes.node to check for objects or arrays of objects

static propTypes = {   children: PropTypes.node.isRequired,}