[Vue] add support for `appEntrypoint` (#5075)

* feat(vue): add support for appEntrypoint

* chore: add changeset

* test(vue): add tests for app entrypoint

* docs(vue): update README to include app entrypoint

* fix(vue): prefer resolvedVirtualModuleId

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

1 files changed, 34 insertions, 0 deletions

diff --git a/packages/integrations/vue/test/app-entrypoint.test.js b/packages/integrations/vue/test/app-entrypoint.test.js
new file mode 100644
index 000000000..1b53fbd21
--- /dev/null
+++ b/packages/integrations/vue/test/app-entrypoint.test.js
@@ -0,0 +1,34 @@
+import { loadFixture } from './test-utils.js';
+import { expect } from 'chai';
+import { parseHTML } from 'linkedom';
+
+describe('App Entrypoint', () => {
+	/** @type {import('./test-utils').Fixture} */
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: './fixtures/app-entrypoint/'
+		});
+		await fixture.build();
+	});
+
+	it('loads during SSR', async () => {
+		const data = await fixture.readFile('/index.html')
+		const { document } = parseHTML(data);
+		const bar = document.querySelector('#foo > #bar');
+		expect(bar).not.to.be.undefined;
+		expect(bar.textContent).to.eq('works');
+	});
+
+	it('setup included in renderer bundle', async () => {
+		const data = await fixture.readFile('/index.html')
+		const { document } = parseHTML(data);
+		const island = document.querySelector('astro-island');
+		const client = island.getAttribute('renderer-url');
+		expect(client).not.to.be.undefined;
+
+		const js = await fixture.readFile(client);
+		expect(js).to.match(/\w+\.component\(\"Bar\"/gm)
+	});
+});