withastro · bluwy · Nov 28, 2022 · Nov 26, 2022
diff --git a/.changeset/swift-papayas-kiss.md b/.changeset/swift-papayas-kiss.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fix astro preview not working on Windows
diff --git a/packages/astro/src/core/preview/index.ts b/packages/astro/src/core/preview/index.ts
@@ -1,5 +1,6 @@
 import type { AstroTelemetry } from '@astrojs/telemetry';
 import { createRequire } from 'module';
+import { pathToFileURL } from 'url';
 import type { AstroSettings, PreviewModule, PreviewServer } from '../../@types/astro';
 import { runHookConfigDone, runHookConfigSetup } from '../../integrations/index.js';
 import type { LogOptions } from '../logger/core';
@@ -41,9 +42,11 @@ export default async function preview(
 	// don't treat this as a dependency of Astro itself. This correctly resolves the
 	// preview entrypoint of the integration package, relative to the user's project root.
 	const require = createRequire(settings.config.root);
-	const previewEntrypoint = require.resolve(settings.adapter.previewEntrypoint);
+	const previewEntrypointUrl = pathToFileURL(
+		require.resolve(settings.adapter.previewEntrypoint)
+	).href;
 
-	const previewModule = (await import(previewEntrypoint)) as Partial<PreviewModule>;
+	const previewModule = (await import(previewEntrypointUrl)) as Partial<PreviewModule>;
 	if (typeof previewModule.default !== 'function') {
 		throw new Error(`[preview] ${settings.adapter.name} cannot preview your app.`);
 	}

diff --git a/packages/astro/test/fixtures/ssr-preview/package.json b/packages/astro/test/fixtures/ssr-preview/package.json
@@ -0,0 +1,8 @@
+{
+  "name": "@test/ssr-preview",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "astro": "workspace:*"
+  }
+}
diff --git a/packages/astro/test/fixtures/ssr-preview/preview.mjs b/packages/astro/test/fixtures/ssr-preview/preview.mjs
@@ -0,0 +1,8 @@
+export default () => {
+	// noop
+	return {
+		port: 3000,
+		closed() {},
+		stop() {}
+	}
+}
diff --git a/packages/astro/test/fixtures/ssr-preview/src/pages/index.astro b/packages/astro/test/fixtures/ssr-preview/src/pages/index.astro
@@ -0,0 +1,8 @@
+<html lang="en">
+	<head>
+		<title>Astro</title>
+	</head>
+	<body>
+		Hello
+	</body>
+</html>
diff --git a/packages/astro/test/ssr-preview.test.js b/packages/astro/test/ssr-preview.test.js
@@ -0,0 +1,22 @@
+import { loadFixture } from './test-utils.js';
+import testAdapter from './test-adapter.js';
+
+describe('SSR Preview', () => {
+	/** @type {import('./test-utils').Fixture} */
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: './fixtures/ssr-preview/',
+			output: 'server',
+			adapter: testAdapter({ extendAdapter: { previewEntrypoint: './preview.mjs' } }),
+		});
+		await fixture.build();
+	});
+
+	it('preview server works', async () => {
+		/** @type {import('./test-utils').PreviewServer} */
+		const previewServer = await fixture.preview();
+		await previewServer.stop();
+	});
+});
diff --git a/packages/astro/test/test-adapter.js b/packages/astro/test/test-adapter.js
@@ -4,7 +4,7 @@ import { viteID } from '../dist/core/util.js';
  *
  * @returns {import('../src/@types/astro').AstroIntegration}
  */
-export default function ({ provideAddress } = { provideAddress: true }) {
+export default function ({ provideAddress = true, extendAdapter } = { provideAddress: true }) {
 	return {
 		name: 'my-ssr-adapter',
 		hooks: {
@@ -66,6 +66,7 @@ export default function ({ provideAddress } = { provideAddress: true }) {
 					name: 'my-ssr-adapter',
 					serverEntrypoint: '@my-ssr',
 					exports: ['manifest', 'createApp'],
+					...extendAdapter,
 				});
 			},
 		},

diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml