fix(react): make children undefined with experimentalReactChildren (

#9141)

* add test script

* make children `undefined` with self-closing tags

* add changeset

* refactor: simplify

.changeset/three-timers-arrive.md

@@ -0,0 +1,5 @@
+---
+'@astrojs/react': patch
+---
+
+Fixes an issue where slotting self-closing elements (img, br, hr) into react components with `experimentalReactChildren` enabled led to an error.

packages/integrations/react/package.json

@@ -42,7 +42,8 @@
   "scripts": {
     "build": "astro-scripts build \"src/**/*.ts\" && tsc",
     "build:ci": "astro-scripts build \"src/**/*.ts\"",
-    "dev": "astro-scripts dev \"src/**/*.ts\""
+    "dev": "astro-scripts dev \"src/**/*.ts\"",
+    "test": "mocha --exit --timeout 20000"
   },
   "dependencies": {
     "@vitejs/plugin-react": "^4.0.4",
@@ -57,7 +58,8 @@
     "cheerio": "1.0.0-rc.12",
     "react": "^18.1.0",
     "react-dom": "^18.1.0",
-    "vite": "^4.4.9"
+    "vite": "^4.4.9",
+    "mocha": "^10.2.0"
   },
   "peerDependencies": {
     "@types/react": "^17.0.50 || ^18.0.21",

packages/integrations/react/test/parsed-react-children.test.js

@@ -0,0 +1,15 @@
+import { expect } from 'chai';
+import convert from "../vnode-children.js";
+
+describe('experimental react children', () => {
+    it('has undefined as children for direct children', () => {
+        const [ imgVNode ] = convert('<img src="abc"></img>');
+        expect(imgVNode.props).to.deep.include({ children: undefined });
+    })
+
+    it('has undefined as children for nested children', () => {
+        const [ divVNode ] = convert('<div><img src="xyz"></img></div>');
+        const [ imgVNode ] = divVNode.props.children;
+        expect(imgVNode.props).to.deep.include({ children: undefined });
+    })
+})

packages/integrations/react/vnode-children.js

@@ -8,24 +8,20 @@ export default function convert(children) {
 	let key = 0;
 
 	function createReactElementFromNode(node) {
-		const childVnodes = Array.isArray(node.children)
+		const childVnodes = Array.isArray(node.children) && node.children.length
 			? node.children
-					.map((child) => {
-						if (child.type === ELEMENT_NODE) {
-							return createReactElementFromNode(child);
-						} else if (child.type === TEXT_NODE) {
-							// 0-length text gets omitted in JSX
-							return child.value.trim() ? child.value : undefined;
-						}
-					})
-					.filter((n) => !!n)
+					.map((child) => createReactElementFromNode(child))
+					.filter(Boolean)
 			: undefined;
 
 		if (node.type === DOCUMENT_NODE) {
 			return createElement(Fragment, {}, childVnodes);
 		} else if (node.type === ELEMENT_NODE) {
 			const { class: className, ...props } = node.attributes;
 			return createElement(node.name, { ...props, className, key: `${id}-${key++}` }, childVnodes);
+		} else if (node.type === TEXT_NODE) {
+			// 0-length text gets omitted in JSX
+			return node.value.trim() ? node.value : undefined;
 		}
 	}