Derive unmount error routing from vnode._parent, dropping the options.unmount parentVNode arg

Author: JoviDeCroock

compat/src/suspense.js

@@ -29,15 +29,15 @@ options._catchError = (error, newVNode, oldVNode, errorInfo) => {
 };
 
 const oldUnmount = options.unmount;
-options.unmount = (vnode, parentVNode) => {
+options.unmount = vnode => {
 	/** @type {import('./internal').Component} */
 	const component = vnode._component;
 	if (component) component._unmounted = true;
 	if (component && component._onResolve) {
 		component._onResolve();
 	}
 
-	if (oldUnmount) oldUnmount(vnode, parentVNode);
+	if (oldUnmount) oldUnmount(vnode);
 };
 
 function detachedClone(vnode, detachedParent, parentDom) {

hooks/src/index.js

@@ -124,18 +124,23 @@ options._commit = (vnode, commitQueue) => {
 	if (oldCommit) oldCommit(vnode, commitQueue);
 };
 
-/** @type {(vnode: import('./internal').VNode, parentVNode?: import('./internal').VNode) => void} */
-options.unmount = (vnode, parentVNode) => {
-	if (oldBeforeUnmount) oldBeforeUnmount(vnode, parentVNode);
+/** @type {(vnode: import('./internal').VNode) => void} */
+options.unmount = vnode => {
+	if (oldBeforeUnmount) oldBeforeUnmount(vnode);
 
 	const c = vnode._component;
 	if (c && c.__hooks) {
 		let hasErrored,
-			errorParent = parentVNode && parentVNode._parent;
+			errorParent = vnode._parent;
 		// The removed subtree is detached (`_parent` nulled) by flush time, so
 		// grab the nearest surviving component now; its current vnode can still
-		// route deferred cleanup errors to a mounted error boundary.
-		while (errorParent && !errorParent._component) {
+		// route deferred cleanup errors to a mounted error boundary. Unmounting
+		// is pre-order and nulls each component's `_parentDom` before its
+		// children unmount, so removed ancestors are already recognizable here.
+		while (
+			errorParent &&
+			!(errorParent._component && errorParent._component._parentDom)
+		) {
 			errorParent = errorParent._parent;
 		}
 		c.__hooks._list.some(s => {

src/diff/index.js

@@ -752,7 +752,7 @@ export function applyRef(ref, value, vnode) {
  */
 export function unmount(vnode, parentVNode, skipRemove) {
 	let r;
-	if (options.unmount) options.unmount(vnode, parentVNode);
+	if (options.unmount) options.unmount(vnode);
 
 	if ((r = vnode.ref) && (!r.current || r.current == vnode._dom)) {
 		applyRef(r, NULL, parentVNode);

src/index.d.ts

@@ -306,7 +306,7 @@ export interface Options {
 	/** Attach a hook that is invoked whenever a VNode is created. */
 	vnode?(vnode: VNode): void;
 	/** Attach a hook that is invoked immediately before a vnode is unmounted. */
-	unmount?(vnode: VNode, parentVNode?: VNode): void;
+	unmount?(vnode: VNode): void;
 	/** Attach a hook that is invoked after a vnode has rendered. */
 	diffed?(vnode: VNode): void;
 	event?(e: Event): any;