Unmount framework components when islands are destroyed (#8264)

* fix(view-transitions): update persistence logic for improved unmount behavior

* feat(astro): add `astro:unmount` event

* feat(vue): automatically unmount islands

* feat(react): automatically unmount islands

* feat(react): automatically unmount islands

* feat(solid): automatically dispose of islands

* feat(svelte): automatically destroy of islands

* feat(svelte): automatically destroy of islands

* feat(solid): automatically dispose of islands

* feat(preact): automatically unmount islands

* chore: update changeset

* fix: rebase issue

* chore: add clarifying comment

* chore: remove duplicate changeset

* chore: add changeset

10 files changed, 63 insertions, 43 deletions

diff --git a/.changeset/ninety-boats-brake.md b/.changeset/ninety-boats-brake.md
new file mode 100644
index 000000000..30c13a820
--- /dev/null
+++ b/.changeset/ninety-boats-brake.md
@@ -0,0 +1,9 @@
+---
+'@astrojs/react': patch
+'@astrojs/preact': patch
+'@astrojs/vue': patch
+'@astrojs/solid-js': patch
+'@astrojs/svelte': patch
+---
+
+Automatically unmount islands when `astro:unmount` is fired
diff --git a/.changeset/perfect-socks-hammer.md b/.changeset/perfect-socks-hammer.md
new file mode 100644
index 000000000..baae63ffe
--- /dev/null
+++ b/.changeset/perfect-socks-hammer.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fire `astro:unmount` event when island is disconnected
diff --git a/packages/astro/components/ViewTransitions.astro b/packages/astro/components/ViewTransitions.astro
index 33741d535..15bad445d 100644
--- a/packages/astro/components/ViewTransitions.astro
+++ b/packages/astro/components/ViewTransitions.astro
@@ -163,18 +163,20 @@ const { fallback = 'animate' } = Astro.props as Props;
 			// Everything left in the new head is new, append it all.
 			document.head.append(...doc.head.children);
 
-			// Move over persist stuff in the body
+			// Persist elements in the existing body
 			const oldBody = document.body;
-			document.body.replaceWith(doc.body);
 			for (const el of oldBody.querySelectorAll(`[${PERSIST_ATTR}]`)) {
 				const id = el.getAttribute(PERSIST_ATTR);
-				const newEl = document.querySelector(`[${PERSIST_ATTR}="${id}"]`);
+				const newEl = doc.querySelector(`[${PERSIST_ATTR}="${id}"]`);
 				if (newEl) {
 					// The element exists in the new page, replace it with the element
 					// from the old page so that state is preserved.
 					newEl.replaceWith(el);
 				}
 			}
+			// Only replace the existing body *AFTER* persistent elements are moved over
+			// This avoids disconnecting `astro-island` nodes multiple times
+			document.body.replaceWith(doc.body);
 
 			// Simulate scroll behavior of Safari and
 			// Chromium based browsers (Chrome, Edge, Opera, ...)
diff --git a/packages/astro/src/runtime/server/astro-island.ts b/packages/astro/src/runtime/server/astro-island.ts
index 7be630d06..e0e09eaec 100644
--- a/packages/astro/src/runtime/server/astro-island.ts
+++ b/packages/astro/src/runtime/server/astro-island.ts
@@ -51,6 +51,12 @@ declare const Astro: {
 				public Component: any;
 				public hydrator: any;
 				static observedAttributes = ['props'];
+				disconnectedCallback() {
+					document.addEventListener('astro:after-swap', () => {
+						// If element wasn't persisted, fire unmount event
+						if (!this.isConnected) this.dispatchEvent(new CustomEvent('astro:unmount'))
+					}, { once: true })
+				}
 				connectedCallback() {
 					if (!this.hasAttribute('await-children') || this.firstChild) {
 						this.childrenConnectedCallback();
diff --git a/packages/integrations/preact/src/client.ts b/packages/integrations/preact/src/client.ts
index f90614398..ad24e886b 100644
--- a/packages/integrations/preact/src/client.ts
+++ b/packages/integrations/preact/src/client.ts
@@ -1,6 +1,6 @@
-import { h, render, type JSX } from 'preact';
-import StaticHtml from './static-html.js';
 import type { SignalLike } from './types';
+import { h, render, hydrate } from 'preact';
+import StaticHtml from './static-html.js';
 
 const sharedSignalMap = new Map<string, SignalLike>();
 
@@ -8,7 +8,8 @@ export default (element: HTMLElement) =>
 	async (
 		Component: any,
 		props: Record<string, any>,
-		{ default: children, ...slotted }: Record<string, any>
+		{ default: children, ...slotted }: Record<string, any>,
+		{ client }: Record<string, string>
 	) => {
 		if (!element.hasAttribute('ssr')) return;
 		for (const [key, value] of Object.entries(slotted)) {
@@ -27,23 +28,13 @@ export default (element: HTMLElement) =>
 			}
 		}
 
-		// eslint-disable-next-line @typescript-eslint/no-shadow
-		function Wrapper({ children }: { children: JSX.Element }) {
-			let attrs = Object.fromEntries(
-				Array.from(element.attributes).map((attr) => [attr.name, attr.value])
-			);
-			return h(element.localName, attrs, children);
-		}
-
-		let parent = element.parentNode as Element;
+		const bootstrap = client !== 'only' ? hydrate : render;
 
-		render(
-			h(
-				Wrapper,
-				null,
-				h(Component, props, children != null ? h(StaticHtml, { value: children }) : children)
-			),
-			parent,
-			element
+		bootstrap(
+			h(Component, props, children != null ? h(StaticHtml, { value: children }) : children),
+			element,
 		);
+		
+		// Preact has no "unmount" option, but you can use `render(null, element)`
+		element.addEventListener('astro:unmount', () => render(null, element), { once: true })
 	};
diff --git a/packages/integrations/react/client-v17.js b/packages/integrations/react/client-v17.js
index 443109603..70bddc353 100644
--- a/packages/integrations/react/client-v17.js
+++ b/packages/integrations/react/client-v17.js
@@ -1,5 +1,5 @@
 import { createElement } from 'react';
-import { render, hydrate } from 'react-dom';
+import { render, hydrate, unmountComponentAtNode } from 'react-dom';
 import StaticHtml from './static-html.js';
 
 export default (element) =>
@@ -12,8 +12,9 @@ export default (element) =>
 			props,
 			children != null ? createElement(StaticHtml, { value: children }) : children
 		);
-		if (client === 'only') {
-			return render(componentEl, element);
-		}
-		return hydrate(componentEl, element);
+
+		const isHydrate = client !== 'only';
+		const bootstrap = isHydrate ? hydrate : render;
+		bootstrap(componentEl, element);
+		element.addEventListener('astro:unmount', () => unmountComponentAtNode(element), { once: true });
 	};
diff --git a/packages/integrations/react/client.js b/packages/integrations/react/client.js
index d8948e7bb..dbd32c0c5 100644
--- a/packages/integrations/react/client.js
+++ b/packages/integrations/react/client.js
@@ -31,10 +31,14 @@ export default (element) =>
 		}
 		if (client === 'only') {
 			return startTransition(() => {
-				createRoot(element).render(componentEl);
+				const root = createRoot(element);
+				root.render(componentEl);
+				element.addEventListener('astro:unmount', () => root.unmount(), { once: true });
 			});
 		}
-		return startTransition(() => {
-			hydrateRoot(element, componentEl, renderOptions);
+		startTransition(() => {
+			const root = hydrateRoot(element, componentEl, renderOptions);
+			root.render(componentEl);
+			element.addEventListener('astro:unmount', () => root.unmount(), { once: true });
 		});
 	};
diff --git a/packages/integrations/solid/src/client.ts b/packages/integrations/solid/src/client.ts
index 730db0f51..66b3767ea 100644
--- a/packages/integrations/solid/src/client.ts
+++ b/packages/integrations/solid/src/client.ts
@@ -9,7 +9,7 @@ export default (element: HTMLElement) =>
 		}
 		if (!element.hasAttribute('ssr')) return;
 
-		const fn = client === 'only' ? render : hydrate;
+		const boostrap = client === 'only' ? render : hydrate;
 
 		let _slots: Record<string, any> = {};
 		if (Object.keys(slotted).length > 0) {
@@ -30,7 +30,7 @@ export default (element: HTMLElement) =>
 		const { default: children, ...slots } = _slots;
 		const renderId = element.dataset.solidRenderId;
 
-		fn(
+		const dispose = boostrap(
 			() =>
 				createComponent(Component, {
 					...props,
@@ -42,4 +42,6 @@ export default (element: HTMLElement) =>
 				renderId,
 			}
 		);
+
+		element.addEventListener('astro:unmount', () => dispose(), { once: true })
 	};
diff --git a/packages/integrations/svelte/client.js b/packages/integrations/svelte/client.js
index 0d07ff2ba..99612a580 100644
--- a/packages/integrations/svelte/client.js
+++ b/packages/integrations/svelte/client.js
@@ -14,7 +14,7 @@ export default (target) => {
 		try {
 			if (import.meta.env.DEV) useConsoleFilter();
 
-			new Component({
+			const component = new Component({
 				target,
 				props: {
 					...props,
@@ -24,6 +24,8 @@ export default (target) => {
 				hydrate: client !== 'only',
 				$$inline: true,
 			});
+			
+			element.addEventListener('astro:unmount', () => component.$destroy(), { once: true })
 		} catch (e) {
 		} finally {
 			if (import.meta.env.DEV) finishUsingConsoleFilter();
diff --git a/packages/integrations/vue/client.js b/packages/integrations/vue/client.js
index ca61116b2..8b2a5eede 100644
--- a/packages/integrations/vue/client.js
+++ b/packages/integrations/vue/client.js
@@ -21,15 +21,13 @@ export default (element) =>
 			content = h(Suspense, null, content);
 		}
 
-		if (client === 'only') {
-			const app = createApp({ name, render: () => content });
-			await setup(app);
-			app.mount(element, false);
-		} else {
-			const app = createSSRApp({ name, render: () => content });
-			await setup(app);
-			app.mount(element, true);
-		}
+		const isHydrate = client !== 'only';
+		const boostrap = isHydrate ? createSSRApp : createApp;
+		const app = boostrap({ name, render: () => content });
+		await setup(app);
+		app.mount(element, isHydrate);
+
+		element.addEventListener('astro:unmount', () => app.unmount(), { once: true });
 	};
 
 function isAsync(fn) {