Enable named slots in renderers (#3652)

* feat: pass all slots to renderers

* refactor: pass `slots` as top-level props

* test: add named slot test for frameworks

* fix: nested hydration, slots that are not initially rendered

* test: add nested-recursive e2e test

* fix: render unmatched custom element children

* chore: update lockfile

* fix: unrendered slots for client:only

* fix(lit): ensure lit integration uses new slots API

* chore: add changeset

* chore: add changesets

* fix: lit slots

* feat: convert dash-case or snake_case slots to camelCase for JSX

* feat: remove tmpl special logic

* test: add slot components-in-markdown test

* refactor: prefer Object.entries.map() to for/of loop

Co-authored-by: Nate Moore <nate@astro.build>

.changeset/clever-pumpkins-begin.md

@@ -0,0 +1,7 @@
+---
+'@astrojs/lit': minor
+---
+
+Adds support for passing named slots from `.astro` => Lit components.
+
+All slots are treated as Light DOM content.

.changeset/lovely-bulldogs-admire.md

@@ -0,0 +1,29 @@
+---
+'@astrojs/preact': minor
+'@astrojs/react': minor
+'@astrojs/solid-js': minor
+---
+
+Add support for passing named slots from `.astro` => framework components.
+
+Each `slot` is be passed as a top-level prop. For example:
+
+```jsx
+// From .astro
+<Component>
+  <h2 slot="title">Hello world!</h2>
+  <h2 slot="slot-with-dash">Dash</h2>
+  <div>Default</div>
+</Component>
+
+// For .jsx
+export default function Component({ title, slotWithDash, children }) {
+  return (
+    <>
+      <div id="title">{title}</div>
+      <div id="slot-with-dash">{slotWithDash}</div>
+      <div id="main">{children}</div>
+    </>
+  )
+}
+```

.changeset/mean-ears-mate.md

@@ -0,0 +1,7 @@
+---
+'astro': patch
+---
+
+Add renderer support for passing named slots to framework components.
+
+**BREAKING**: integrations using the `addRenderer()` API are now passed all named slots via `Record<string, string>` rather than `string`. Previously only the default slot was passed.

.changeset/tough-ants-rest.md

@@ -0,0 +1,8 @@
+---
+'@astrojs/svelte': minor
+'@astrojs/vue': minor
+---
+
+Adds support for passing named slots from `.astro` => framework components.
+
+Inside your components, use the built-in `slot` API as you normally would.

packages/astro/e2e/fixtures/nested-recursive/astro.config.mjs

@@ -0,0 +1,12 @@
+import { defineConfig } from 'astro/config';
+import preact from '@astrojs/preact';
+import react from '@astrojs/react';
+import svelte from '@astrojs/svelte';
+import vue from '@astrojs/vue';
+import solid from '@astrojs/solid-js';
+
+// https://astro.build/config
+export default defineConfig({
+	// Enable many frameworks to support all different kinds of components.
+	integrations: [preact(), react(), svelte(), vue(), solid()],
+});

packages/astro/e2e/fixtures/nested-recursive/package.json

@@ -0,0 +1,24 @@
+{
+  "name": "@e2e/nested-recursive",
+  "version": "0.0.0",
+  "private": true,
+  "devDependencies": {
+    "@astrojs/preact": "workspace:*",
+    "@astrojs/react": "workspace:*",
+    "@astrojs/solid-js": "workspace:*",
+    "@astrojs/svelte": "workspace:*",
+    "@astrojs/vue": "workspace:*",
+    "astro": "workspace:*"
+  },
+  "dependencies": {
+    "preact": "^10.7.3",
+    "react": "^18.1.0",
+    "react-dom": "^18.1.0",
+    "solid-js": "^1.4.3",
+    "svelte": "^3.48.0",
+    "vue": "^3.2.36"
+  },
+  "scripts": {
+    "dev": "astro dev"
+  }
+}

packages/astro/e2e/fixtures/nested-recursive/src/components/PreactCounter.tsx

@@ -0,0 +1,17 @@
+import { useState } from 'preact/hooks';
+
+/** a counter written in Preact */
+export default function PreactCounter({ children, id }) {
+	const [count, setCount] = useState(0);
+	const add = () => setCount((i) => i + 1);
+	const subtract = () => setCount((i) => i - 1);
+
+	return (
+		<div id={id} class="counter">
+			<button class="decrement" onClick={subtract}>-</button>
+			<pre id={`${id}-count`}>{count}</pre>
+			<button id={`${id}-increment`} class="increment" onClick={add}>+</button>
+			<div class="children">{children}</div>
+		</div>
+	);
+}

packages/astro/e2e/fixtures/nested-recursive/src/components/ReactCounter.jsx

@@ -0,0 +1,17 @@
+import { useState } from 'react';
+
+/** a counter written in React */
+export default function ReactCounter({ children, id }) {
+	const [count, setCount] = useState(0);
+	const add = () => setCount((i) => i + 1);
+	const subtract = () => setCount((i) => i - 1);
+
+	return (
+		<div id={id} className="counter">
+			<button className="decrement" onClick={subtract}>-</button>
+			<pre id={`${id}-count`}>{count}</pre>
+			<button id={`${id}-increment`} className="increment" onClick={add}>+</button>
+			<div className="children">{children}</div>
+		</div>
+	);
+}

packages/astro/e2e/fixtures/nested-recursive/src/components/SolidCounter.tsx

@@ -0,0 +1,17 @@
+import { createSignal } from 'solid-js';
+
+/** a counter written with Solid */
+export default function SolidCounter({ children, id }) {
+	const [count, setCount] = createSignal(0);
+	const add = () => setCount(count() + 1);
+	const subtract = () => setCount(count() - 1);
+
+	return (
+			<div id={id} class="counter">
+				<button class="decrement" onClick={subtract}>-</button>
+				<pre id={`${id}-count`}>{count()}</pre>
+				<button id={`${id}-increment`} class="increment" onClick={add}>+</button>
+				<div class="children">{children}</div>
+			</div>
+	);
+}

packages/astro/e2e/fixtures/nested-recursive/src/components/SvelteCounter.svelte

@@ -0,0 +1,29 @@
+
+<script>
+	export let id;
+  let children;
+  let count = 0;
+
+  function add() {
+		count += 1;
+	}
+
+  function subtract() {
+		count -= 1;
+	}
+</script>
+
+<div {id} class="counter">
+  <button class="decrement" on:click={subtract}>-</button>
+  <pre id={`${id}-count`}>{ count }</pre>
+  <button id={`${id}-increment`} class="increment" on:click={add}>+</button>
+	<div class="children">
+		<slot />
+	</div>
+</div>
+
+<style>
+	.counter {
+		background: white;
+	}
+</style>

packages/astro/e2e/fixtures/nested-recursive/src/components/VueCounter.vue

@@ -0,0 +1,34 @@
+<template>
+	<div :id="id" class="counter">
+		<button class="decrement" @click="subtract()">-</button>
+		<pre :id="`${id}-count`">{{ count }}</pre>
+		<button :id="`${id}-increment`" class="increment" @click="add()">+</button>
+		<div class="children">
+			<slot />
+		</div>
+	</div>
+</template>
+
+<script>
+import { ref } from 'vue';
+export default {
+	props: {
+		id: {
+			type: String,
+			required: true
+		}
+  },
+	setup(props) {
+		const count = ref(0);
+		const add = () => (count.value = count.value + 1);
+		const subtract = () => (count.value = count.value - 1);
+
+		return {
+			id: props.id,
+			count,
+			add,
+			subtract,
+		};
+	},
+};
+</script>

packages/astro/e2e/fixtures/nested-recursive/src/pages/index.astro

@@ -0,0 +1,28 @@
+---
+import ReactCounter from '../components/ReactCounter.jsx';
+import PreactCounter from '../components/PreactCounter.tsx';
+import SolidCounter from '../components/SolidCounter.tsx';
+import VueCounter from '../components/VueCounter.vue';
+import SvelteCounter from '../components/SvelteCounter.svelte';
+---
+
+<html lang="en">
+	<head>
+		<meta charset="utf-8" />
+		<meta name="viewport" content="width=device-width" />
+		<link rel="icon" type="image/x-icon" href="/favicon.ico" />
+	</head>
+	<body>
+		<main>
+			<ReactCounter id="react-counter" client:idle>
+				<PreactCounter id="preact-counter" client:idle>
+					<SolidCounter id="solid-counter" client:idle>
+						<SvelteCounter id="svelte-counter" client:idle>
+							<VueCounter id="vue-counter" client:idle />
+						</SvelteCounter>
+					</SolidCounter>
+				</PreactCounter>
+			</ReactCounter>
+		</main>
+	</body>
+</html>

packages/astro/e2e/nested-recursive.test.js

@@ -0,0 +1,96 @@
+import { test as base, expect } from '@playwright/test';
+import { loadFixture } from './test-utils.js';
+
+const test = base.extend({
+	astro: async ({}, use) => {
+		const fixture = await loadFixture({ root: './fixtures/nested-recursive/' });
+		await use(fixture);
+	},
+});
+
+let devServer;
+
+test.beforeEach(async ({ astro }) => {
+	devServer = await astro.startDevServer();
+});
+
+test.afterEach(async () => {
+	await devServer.stop();
+});
+
+test.describe('Recursive Nested Frameworks', () => {
+	test('React counter', async ({ astro, page }) => {
+		await page.goto('/');
+
+		const counter = await page.locator('#react-counter');
+		await expect(counter, 'component is visible').toBeVisible();
+
+		const count = await counter.locator('#react-counter-count');
+		await expect(count, 'initial count is 0').toHaveText('0');
+
+		const increment = await counter.locator('#react-counter-increment');
+		await increment.click();
+
+		await expect(count, 'count incremented by 1').toHaveText('1');
+	});
+
+	test('Preact counter', async ({ astro, page }) => {
+		await page.goto('/');
+
+		const counter = await page.locator('#preact-counter');
+		await expect(counter, 'component is visible').toBeVisible();
+
+		const count = await counter.locator('#preact-counter-count');
+		await expect(count, 'initial count is 0').toHaveText('0');
+
+		const increment = await counter.locator('#preact-counter-increment');
+		await increment.click();
+
+		await expect(count, 'count incremented by 1').toHaveText('1');
+	});
+
+	test('Solid counter', async ({ astro, page }) => {
+		await page.goto('/');
+
+		const counter = await page.locator('#solid-counter');
+		await expect(counter, 'component is visible').toBeVisible();
+
+		const count = await counter.locator('#solid-counter-count');
+		await expect(count, 'initial count is 0').toHaveText('0');
+
+		const increment = await counter.locator('#solid-counter-increment');
+		await increment.click();
+
+		await expect(count, 'count incremented by 1').toHaveText('1');
+	});
+
+	test('Vue counter', async ({ astro, page }) => {
+		await page.goto('/');
+
+		const counter = await page.locator('#vue-counter');
+		await expect(counter, 'component is visible').toBeVisible();
+
+		const count = await counter.locator('#vue-counter-count');
+		await expect(count, 'initial count is 0').toHaveText('0');
+
+		const increment = await counter.locator('#vue-counter-increment');
+		await increment.click();
+
+		await expect(count, 'count incremented by 1').toHaveText('1');
+	});
+
+	test('Svelte counter', async ({ astro, page }) => {
+		await page.goto('/');
+
+		const counter = await page.locator('#svelte-counter');
+		await expect(counter, 'component is visible').toBeVisible();
+
+		const count = await counter.locator('#svelte-counter-count');
+		await expect(count, 'initial count is 0').toHaveText('0');
+
+		const increment = await counter.locator('#svelte-counter-increment');
+		await increment.click();
+
+		await expect(count, 'count incremented by 1').toHaveText('1');
+	});
+});

packages/astro/src/@types/astro.ts

@@ -737,7 +737,7 @@ export interface AstroConfig extends z.output<typeof AstroConfigSchema> {
 export type AsyncRendererComponentFn<U> = (
 	Component: any,
 	props: any,
-	children: string | undefined,
+	slots: Record<string, string>,
 	metadata?: AstroComponentMetadata
 ) => Promise<U>;
 

packages/astro/src/runtime/server/astro-island.ts

@@ -64,23 +64,24 @@ declare const Astro: {
 					if (!this.hydrator || this.parentElement?.closest('astro-island[ssr]')) {
 						return;
 					}
-					let innerHTML: string | null = null;
-					let fragment = this.querySelector('astro-fragment');
-					if (fragment == null && this.hasAttribute('tmpl')) {
-						// If there is no child fragment, check to see if there is a template.
-						// This happens if children were passed but the client component did not render any.
-						let template = this.querySelector('template[data-astro-template]');
-						if (template) {
-							innerHTML = template.innerHTML;
-							template.remove();
-						}
-					} else if (fragment) {
-						innerHTML = fragment.innerHTML;
+					const slotted = this.querySelectorAll('astro-slot');
+					const slots: Record<string, string> = {};
+					// Always check to see if there are templates.
+					// This happens if slots were passed but the client component did not render them.
+					const templates = this.querySelectorAll('template[data-astro-template]');
+					for (const template of templates) {
+						if (!template.closest(this.tagName)?.isSameNode(this)) continue;
+						slots[template.getAttribute('data-astro-template') || 'default'] = template.innerHTML;
+						template.remove();
+					}
+					for (const slot of slotted) {
+						if (!slot.closest(this.tagName)?.isSameNode(this)) continue;
+						slots[slot.getAttribute('name') || 'default'] = slot.innerHTML;
 					}
 					const props = this.hasAttribute('props')
 						? JSON.parse(this.getAttribute('props')!, reviver)
 						: {};
-					this.hydrator(this)(this.Component, props, innerHTML, {
+					this.hydrator(this)(this.Component, props, slots, {
 						client: this.getAttribute('client'),
 					});
 					this.removeAttribute('ssr');