withastro · florian-lefebvre · Oct 3, 2024 · Oct 3, 2024
diff --git a/.changeset/beige-students-compete.md b/.changeset/beige-students-compete.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/vue': patch
+---
+
+Fixes a case where IDs generated by `useId()` (introduced in Vue 3.5) would not be unique between islands
diff --git a/packages/integrations/vue/client.js b/packages/integrations/vue/client.js
@@ -40,6 +40,7 @@ export default (element) =>
 					return content;
 				},
 			});
+			app.config.idPrefix = element.getAttribute('prefix');
 			await setup(app);
 			app.mount(element, isHydrate);
 			appMap.set(element, appInstance);

diff --git a/packages/integrations/vue/context.js b/packages/integrations/vue/context.js
@@ -0,0 +1,24 @@
+const contexts = new WeakMap();
+
+const ID_PREFIX = 'v';
+
+function getContext(rendererContextResult) {
+	if (contexts.has(rendererContextResult)) {
+		return contexts.get(rendererContextResult);
+	}
+	const ctx = {
+		currentIndex: 0,
+		get id() {
+			return ID_PREFIX + this.currentIndex.toString();
+		},
+	};
+	contexts.set(rendererContextResult, ctx);
+	return ctx;
+}
+
+export function incrementId(rendererContextResult) {
+	const ctx = getContext(rendererContextResult);
+	const id = ctx.id;
+	ctx.currentIndex++;
+	return id;
+}
diff --git a/packages/integrations/vue/server.js b/packages/integrations/vue/server.js
@@ -2,12 +2,19 @@ import { setup } from 'virtual:@astrojs/vue/app';
 import { createSSRApp, h } from 'vue';
 import { renderToString } from 'vue/server-renderer';
 import StaticHtml from './static-html.js';
+import { incrementId } from './context.js';
 
 function check(Component) {
 	return !!Component['ssrRender'] || !!Component['__ssrInlineRender'];
 }
 
 async function renderToStaticMarkup(Component, inputProps, slotted, metadata) {
+	let prefix;
+	if (this && this.result) {
+		prefix = incrementId(this.result);
+	}
+	const attrs = { prefix };
+
 	const slots = {};
 	const props = { ...inputProps };
 	delete props.slot;
@@ -21,9 +28,10 @@ async function renderToStaticMarkup(Component, inputProps, slotted, metadata) {
 			});
 	}
 	const app = createSSRApp({ render: () => h(Component, props, slots) });
+	app.config.idPrefix = prefix;
 	await setup(app);
 	const html = await renderToString(app);
-	return { html };
+	return { html, attrs };
 }
 
 export default {

diff --git a/packages/integrations/vue/test/basics.test.js b/packages/integrations/vue/test/basics.test.js
@@ -30,4 +30,13 @@ describe('Basics', () => {
 		assert.notEqual(img, undefined);
 		assert.equal(img.getAttribute('src'), '/light_walrus.avif');
 	});
+
+	it('Should generate unique ids when using useId()', async () => {
+		const data = await fixture.readFile('/index.html');
+		const { document } = parseHTML(data);
+
+		const els = document.querySelectorAll('.vue-use-id');
+		assert.equal(els.length, 2);
+		assert.notEqual(els[0].getAttribute('id'), els[1].getAttribute('id'));
+	});
 });
diff --git a/packages/integrations/vue/test/fixtures/basics/src/components/WithId.vue b/packages/integrations/vue/test/fixtures/basics/src/components/WithId.vue
@@ -0,0 +1,9 @@
+<script setup>
+import { useId } from "vue"
+
+const id = useId()
+</script>
+
+<template>
+    <p class="vue-use-id" :id="id">{{ id }}</p>
+</template>
diff --git a/packages/integrations/vue/test/fixtures/basics/src/pages/index.astro b/packages/integrations/vue/test/fixtures/basics/src/pages/index.astro
@@ -1,6 +1,7 @@
 ---
 import Bar from '../components/Foo.vue';
 import Parent from '../components/Parent.astro';
+import WithId from '../components/WithId.vue';
 ---
 <html>
 	<head>
@@ -10,5 +11,7 @@ import Parent from '../components/Parent.astro';
 		<Parent>
 			<Bar slot="footer" />
 		</Parent>
+		<WithId client:idle />
+		<WithId client:idle />
 	</body>
 </html>