preact/compat/src/Children.js

Fast 4kb React-compatible Virtual DOM library.

import { toChildArray } from 'preact';

const mapFn = (children, fn, context) => {
	if (children == null) return null;
	return toChildArray(toChildArray(children).map(fn.bind(context)));
};

// This API is completely unnecessary for Preact, so it's basically passthrough.
export const Children = {
	map: mapFn,
	forEach: mapFn,
	count(children) {
		return children ? toChildArray(children).length : 0;
	},
	only(children) {
		const normalized = toChildArray(children);
		if (normalized.length != 1) throw 'Children.only';
		return normalized[0];
	},
	toArray: toChildArray
};