preact/src/vdom/functional-component.js

import { EMPTY } from '../constants';
import { getNodeProps } from './index';
import { isFunction } from '../util';


/** Check if a VNode is a reference to a stateless functional component.
 *	A function component is represented as a VNode whose `nodeName` property is a reference to a function.
 *	If that function is not a Component (ie, has no `.render()` method on a prototype), it is considered a stateless functional component.
 *	@param {VNode} vnode	A VNode
 *	@private
 */
export function isFunctionalComponent(vnode) {
	let nodeName = vnode && vnode.nodeName;
	return nodeName && isFunction(nodeName) && !(nodeName.prototype && nodeName.prototype.render);
}



/** Construct a resultant VNode from a VNode referencing a stateless functional component.
 *	@param {VNode} vnode	A VNode with a `nodeName` property that is a reference to a function.
 *	@private
 */
export function buildFunctionalComponent(vnode, context) {
	return vnode.nodeName(getNodeProps(vnode), context || EMPTY);
}