7 files changed, 85 insertions, 7 deletions
diff --git a/.changeset/wet-beds-act.md b/.changeset/wet-beds-act.md
new file mode 100644
index 000000000..da9367a9d
--- /dev/null
+++ b/.changeset/wet-beds-act.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Updates component hydration scripts to use absolute paths for script imports
diff --git a/packages/astro/src/core/app/index.ts b/packages/astro/src/core/app/index.ts
index a53c1c062..c630e3de3 100644
--- a/packages/astro/src/core/app/index.ts
+++ b/packages/astro/src/core/app/index.ts
@@ -18,7 +18,7 @@ import {
 	createLinkStylesheetElementSet,
 	createModuleScriptElementWithSrcSet,
 } from '../render/ssr-element.js';
-import { prependForwardSlash } from '../path.js';
+import { joinPaths, prependForwardSlash } from '../path.js';
 
 export const pagesVirtualModuleId = '@astrojs-pages-virtual-entry';
 export const resolvedPagesVirtualModuleId = '\0' + pagesVirtualModuleId;
@@ -108,7 +108,7 @@ export class App {
 					throw new Error(`Unable to resolve [${specifier}]`);
 				}
 				const bundlePath = manifest.entryModules[specifier];
-				return bundlePath.startsWith('data:') ? bundlePath : prependForwardSlash(bundlePath);
+				return bundlePath.startsWith('data:') ? bundlePath : prependForwardSlash(joinPaths(manifest.base, bundlePath));
 			},
 			route: routeData,
 			routeCache: this.#routeCache,
diff --git a/packages/astro/src/core/app/types.ts b/packages/astro/src/core/app/types.ts
index 063f33b7f..6c6e879d5 100644
--- a/packages/astro/src/core/app/types.ts
+++ b/packages/astro/src/core/app/types.ts
@@ -22,6 +22,7 @@ export type SerializedRouteInfo = Omit<RouteInfo, 'routeData'> & {
 export interface SSRManifest {
 	routes: RouteInfo[];
 	site?: string;
+	base?: string;
 	markdown: MarkdownRenderingOptions;
 	pageMap: Map<ComponentPath, ComponentInstance>;
 	renderers: SSRLoadedRenderer[];
diff --git a/packages/astro/src/core/build/generate.ts b/packages/astro/src/core/build/generate.ts
index d68f8faf3..d0dec38be 100644
--- a/packages/astro/src/core/build/generate.ts
+++ b/packages/astro/src/core/build/generate.ts
@@ -219,9 +219,7 @@ async function generatePath(
 				}
 				throw new Error(`Cannot find the built path for ${specifier}`);
 			}
-			const relPath = npath.posix.relative(pathname, '/' + hashedFilePath);
-			const fullyRelativePath = relPath[0] === '.' ? relPath : './' + relPath;
-			return fullyRelativePath;
+			return prependForwardSlash(npath.posix.join(astroConfig.base, hashedFilePath));
 		},
 		request: createRequest({ url, headers: new Headers(), logging, ssr }),
 		route: pageData.route,
diff --git a/packages/astro/src/core/build/vite-plugin-ssr.ts b/packages/astro/src/core/build/vite-plugin-ssr.ts
index 35d95e6a2..2b2915ff0 100644
--- a/packages/astro/src/core/build/vite-plugin-ssr.ts
+++ b/packages/astro/src/core/build/vite-plugin-ssr.ts
@@ -136,6 +136,7 @@ function buildManifest(
 	const ssrManifest: SerializedSSRManifest = {
 		routes,
 		site: astroConfig.site,
+		base: astroConfig.base,
 		markdown: astroConfig.markdown,
 		pageMap: null as any,
 		renderers: [],
diff --git a/packages/astro/test/astro-client-only.test.js b/packages/astro/test/astro-client-only.test.js
index 5e2cc6ce8..527932a01 100644
--- a/packages/astro/test/astro-client-only.test.js
+++ b/packages/astro/test/astro-client-only.test.js
@@ -22,7 +22,39 @@ describe('Client only components', () => {
 		const script = $script.html();
 
 		// test 2: svelte renderer is on the page
-		expect(/import\(".\/entry.*/g.test(script)).to.be.ok;
+		expect(/import\("\/entry.*/g.test(script)).to.be.ok;
+	});
+
+	it('Adds the CSS to the page', async () => {
+		const html = await fixture.readFile('/index.html');
+		const $ = cheerioLoad(html);
+		expect($('link[rel=stylesheet]')).to.have.lengthOf(2);
+	});
+});
+
+describe('Client only components subpath', () => {
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			site: 'https://site.com',
+			base: '/blog',
+			root: './fixtures/astro-client-only/',
+		});
+		await fixture.build();
+	});
+
+	it('Loads pages using client:only hydrator', async () => {
+		const html = await fixture.readFile('/index.html');
+		const $ = cheerioLoad(html);
+
+		// test 1: <astro-root> is empty
+		expect($('astro-root').html()).to.equal('');
+		const $script = $('script');
+		const script = $script.html();
+
+		// test 2: svelte renderer is on the page
+		expect(/import\("\/blog\/entry.*/g.test(script)).to.be.ok;
 	});
 
 	it('Adds the CSS to the page', async () => {
diff --git a/packages/astro/test/astro-dynamic.test.js b/packages/astro/test/astro-dynamic.test.js
index 1b8b323ee..9e90f073a 100644
--- a/packages/astro/test/astro-dynamic.test.js
+++ b/packages/astro/test/astro-dynamic.test.js
@@ -37,6 +37,47 @@ describe('Dynamic components', () => {
 		// test 2: correct script is being loaded.
 		// because of bundling, we don't have access to the source import,
 		// only the bundled import.
-		expect($('script').html()).to.include(`import setup from '../entry`);
+		expect($('script').html()).to.include(`import setup from '/entry`);
+	});
+});
+
+describe('Dynamic components subpath', () => {
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			site: 'https://site.com',
+			base: '/blog',
+			root: './fixtures/astro-dynamic/',
+		});
+		await fixture.build();
+	});
+
+	it('Loads packages that only run code in client', async () => {
+		const html = await fixture.readFile('/index.html');
+
+		const $ = cheerio.load(html);
+		expect($('script').length).to.eq(2);
+	});
+
+	it('Loads pages using client:media hydrator', async () => {
+		const root = new URL('http://example.com/media/index.html');
+		const html = await fixture.readFile('/media/index.html');
+		const $ = cheerio.load(html);
+
+		// test 1: static value rendered
+		expect($('script').length).to.equal(2); // One for each
+	});
+
+	it('Loads pages using client:only hydrator', async () => {
+		const html = await fixture.readFile('/client-only/index.html');
+		const $ = cheerio.load(html);
+
+		// test 1: <astro-root> is empty.
+		expect($('<astro-root>').html()).to.equal('');
+		// test 2: correct script is being loaded.
+		// because of bundling, we don't have access to the source import,
+		// only the bundled import.
+		expect($('script').html()).to.include(`import setup from '/blog/entry`);
 	});
 });