Function createRoot

packages/react-noop-renderer/src/root.ts:15–107

()

let idCounter = 0;

export function createRoot() {
	const container: Container = {
		rootID: idCounter++,
		children: []
	};

	// @ts-ignore
	const root = createContainer(container);

	function getChildren(parent: Container | Instance) {
		if (parent) {
			return parent.children;
		}
		return null;
	}

	function getChildrenAsJSX(root: Container) {
		const children = childToJSX(getChildren(root));
		if (Array.isArray(children)) {
			return {
				$$typeof: REACT_ELEMENT_TYPE,
				type: REACT_FRAGMENT_TYPE,
				key: null,
				ref: null,
				props: { children },
				__mark: 'KaSong'
			};
		}
		return children;
	}

	function childToJSX(child: any): any {
		if (typeof child === 'string' || typeof child === 'number') {
			return child;
		}

		if (Array.isArray(child)) {
			if (child.length === 0) {
				return null;
			}
			if (child.length === 1) {
				return childToJSX(child[0]);
			}
			const children = child.map(childToJSX);

			if (
				children.every(
					(child) => typeof child === 'string' || typeof child === 'number'
				)
			) {
				return children.join('');
			}
			// [TextInstance, TextInstance, Instance]
			return children;
		}

		// Instance
		if (Array.isArray(child.children)) {