1 files changed, 41 insertions, 0 deletions
diff --git a/packages/astro/test/astro-preview-headers.test.js b/packages/astro/test/astro-preview-headers.test.js
new file mode 100644
index 000000000..d33f46376
--- /dev/null
+++ b/packages/astro/test/astro-preview-headers.test.js
@@ -0,0 +1,41 @@
+import assert from 'node:assert/strict';
+import { after, before, describe, it } from 'node:test';
+import { loadFixture } from './test-utils.js';
+
+describe('Astro preview headers', () => {
+	let fixture;
+	let previewServer;
+	const headers = {
+		astro: 'test',
+	};
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: './fixtures/astro-preview-headers/',
+			server: {
+				headers,
+			},
+		});
+		await fixture.build();
+		previewServer = await fixture.preview();
+	});
+
+	// important: close preview server (free up port and connection)
+	after(async () => {
+		await previewServer.stop();
+	});
+
+	describe('preview', () => {
+		it('returns custom headers for valid URLs', async () => {
+			const result = await fixture.fetch('/');
+			assert.equal(result.status, 200);
+			assert.equal(Object.fromEntries(result.headers).astro, headers.astro);
+		});
+
+		it('does not return custom headers for invalid URLs', async () => {
+			const result = await fixture.fetch('/bad-url');
+			assert.equal(result.status, 404);
+			assert.equal(Object.fromEntries(result.headers).hasOwnProperty('astro'), false);
+		});
+	});
+});