Fix namespaced component usage in MDX (#4272)

* fix(#4209): handle namespaced JSX and MDX

* chore: add changeset

* chore: update lockfile

* fix: throw error when componentExport is unresolved

* chore: bump compiler

* chore: bump compiler

* chore: revert example changes

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

6 files changed, 109 insertions, 0 deletions

diff --git a/packages/integrations/mdx/test/fixtures/mdx-namespace/astro.config.mjs b/packages/integrations/mdx/test/fixtures/mdx-namespace/astro.config.mjs
new file mode 100644
index 000000000..4671227d3
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/mdx-namespace/astro.config.mjs
@@ -0,0 +1,6 @@
+import mdx from '@astrojs/mdx';
+import react from '@astrojs/react';
+
+export default {
+	integrations: [react(), mdx()]
+}
diff --git a/packages/integrations/mdx/test/fixtures/mdx-namespace/package.json b/packages/integrations/mdx/test/fixtures/mdx-namespace/package.json
new file mode 100644
index 000000000..7917f372d
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/mdx-namespace/package.json
@@ -0,0 +1,8 @@
+{
+  "name": "@test/mdx-namespace",
+  "dependencies": {
+    "astro": "workspace:*",
+    "@astrojs/mdx": "workspace:*",
+    "@astrojs/react": "workspace:*"
+  }
+}
diff --git a/packages/integrations/mdx/test/fixtures/mdx-namespace/src/components/Component.jsx b/packages/integrations/mdx/test/fixtures/mdx-namespace/src/components/Component.jsx
new file mode 100644
index 000000000..19a3d9c19
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/mdx-namespace/src/components/Component.jsx
@@ -0,0 +1,6 @@
+const Component = () => {
+  return <p id="component">Hello world</p>;
+};
+export const ns = {
+	Component
+}
diff --git a/packages/integrations/mdx/test/fixtures/mdx-namespace/src/pages/object.mdx b/packages/integrations/mdx/test/fixtures/mdx-namespace/src/pages/object.mdx
new file mode 100644
index 000000000..6f3990137
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/mdx-namespace/src/pages/object.mdx
@@ -0,0 +1,3 @@
+import * as mod from '../components/Component.jsx';
+
+<mod.ns.Component client:load />
diff --git a/packages/integrations/mdx/test/fixtures/mdx-namespace/src/pages/star.mdx b/packages/integrations/mdx/test/fixtures/mdx-namespace/src/pages/star.mdx
new file mode 100644
index 000000000..b3af5422c
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/mdx-namespace/src/pages/star.mdx
@@ -0,0 +1,3 @@
+import { ns } from '../components/Component.jsx';
+
+<ns.Component client:load />
diff --git a/packages/integrations/mdx/test/mdx-namespace.test.js b/packages/integrations/mdx/test/mdx-namespace.test.js
new file mode 100644
index 000000000..ad9587640
--- /dev/null
+++ b/packages/integrations/mdx/test/mdx-namespace.test.js
@@ -0,0 +1,83 @@
+import { expect } from 'chai';
+import { parseHTML } from 'linkedom';
+import { loadFixture } from '../../../astro/test/test-utils.js';
+
+describe('MDX Namespace', () => {
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: new URL('./fixtures/mdx-namespace/', import.meta.url),
+		});
+	});
+
+	describe('build', () => {
+		before(async () => {
+			await fixture.build();
+		});
+
+		it('works for object', async () => {
+			const html = await fixture.readFile('/object/index.html');
+			const { document } = parseHTML(html);
+
+			const island = document.querySelector('astro-island');
+			const component = document.querySelector('#component');
+
+			expect(island).not.undefined;
+			expect(component.textContent).equal('Hello world')
+		});
+
+		it('works for star', async () => {
+			const html = await fixture.readFile('/star/index.html');
+			const { document } = parseHTML(html);
+
+			const island = document.querySelector('astro-island');
+			const component = document.querySelector('#component');
+
+			expect(island).not.undefined;
+			expect(component.textContent).equal('Hello world')
+		});
+	});
+
+	describe('dev', () => {
+		let devServer;
+
+		before(async () => {
+			devServer = await fixture.startDevServer();
+		});
+
+		after(async () => {
+			await devServer.stop();
+		});
+
+		it('works for object', async () => {
+			const res = await fixture.fetch('/object');
+
+			expect(res.status).to.equal(200);
+
+			const html = await res.text();
+			const { document } = parseHTML(html);
+
+			const island = document.querySelector('astro-island');
+			const component = document.querySelector('#component');
+
+			expect(island).not.undefined;
+			expect(component.textContent).equal('Hello world')
+		});
+
+		it('works for star', async () => {
+			const res = await fixture.fetch('/star');
+
+			expect(res.status).to.equal(200);
+
+			const html = await res.text();
+			const { document } = parseHTML(html);
+
+			const island = document.querySelector('astro-island');
+			const component = document.querySelector('#component');
+
+			expect(island).not.undefined;
+			expect(component.textContent).equal('Hello world')
+		});
+	});
+});