fix: async loader missing undefined check (#1763)

* fix: Bail from `getPreviousSibling` if VNode undefined

Co-authored-by: psabharwal123 <puneet.sabharwal@hotmail.com>
Co-authored-by: Sparrowhawk <sparrowhawk-ea@hotmail.com>

* docs: Adding changeset

* test: Update build hashes

Co-authored-by: psabharwal123 <puneet.sabharwal@hotmail.com>
Co-authored-by: Sparrowhawk <sparrowhawk-ea@hotmail.com>

.changeset/odd-cups-invent.md

@@ -0,0 +1,5 @@
+---
+'@preact/async-loader': patch
+---
+
+Fix for possible type error in `async-loader`

packages/async-loader/async.js

@@ -5,7 +5,7 @@ const PENDING = {};
 // Given a VNode, finds its previous element sibling
 function getPreviousSibling(vnode, inner) {
 	// in an element parent with no preceeding siblings means we're the first child
-	if (typeof vnode.type === 'string') return null;
+	if (!vnode || typeof vnode.type === 'string') return null;
 	const parent = vnode.__;
 	if (!parent) return;
 	let children = parent.__k;
@@ -16,7 +16,7 @@ function getPreviousSibling(vnode, inner) {
 		if (end === -1) end = children.length;
 		for (let i = end; i--; ) {
 			const child = children[i];
-			const dom = (child && child.__e) || getPreviousSibling(child, true);
+			const dom = child && (child.__e || getPreviousSibling(child, true));
 			if (dom) return dom;
 		}
 	}

packages/cli/tests/images/build.js

@@ -17,8 +17,8 @@ exports.default = Object.assign({}, common, {
 	'ssr-build/ssr-bundle.js.map': 52686,
 	'ssr-build/asset-manifest.json': 178,
 	'bundle.259c5.css': 901,
-	'bundle.f79fb.js': 21429,
-	'bundle.f79fb.js.map': 111801,
+	'bundle.85124.js': 21429,
+	'bundle.85124.js.map': 111801,
 	'favicon.ico': 15086,
 	'index.html': 2034,
 	'manifest.json': 455,