Fall back to requestUrl.origin in RemoteRuntimeFontFileUrlResolver when server address is null

.changeset/better-zebras-notice.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes a bug where `experimental_getFontFileURL()` rejected valid font URLs when using the Cloudflare adapter

packages/astro/src/assets/fonts/infra/remote-runtime-font-file-url-resolver.ts

@@ -6,9 +6,11 @@ import type { RuntimeFontFileUrlResolver } from '../definitions.js';
  * During prerendering, a temporary Node HTTP server is started to
  * serve font files.
  *
- * We send request to the provided server address. `requestUrl` on
- * `fetch` is not implemented because we have the information from
- * within the Vite plugin already.
+ * When possible, the resolver uses a statically known server
+ * {@link address}. When the address is not yet available (e.g. the
+ * virtual module was evaluated before the HTTP server started
+ * listening — see #17722), the resolver falls back to deriving the
+ * origin from the caller-supplied {@link requestUrl}.
  */
 export class RemoteRuntimeFontFileUrlResolver implements RuntimeFontFileUrlResolver {
 	#urls: Set<string>;
@@ -25,19 +27,31 @@ export class RemoteRuntimeFontFileUrlResolver implements RuntimeFontFileUrlResol
 		this.#address = address;
 	}
 
-	resolve(url: string): string | null {
+	resolve(url: string, requestUrl: URL | undefined): string | null {
 		if (!this.#urls.has(url)) {
 			return null;
 		}
-		if (!this.#address) {
-			throw new Error('Server address unavailable, this should not happen. Open an issue.');
-		}
 		// assetsPrefix
 		if (!url.startsWith('/')) {
-			url = new URL(url).pathname;
+			if (this.#address) {
+				url = new URL(url).pathname;
+			} else {
+				return url;
+			}
+		}
+		if (this.#address) {
+			const host =
+				this.#address.family === 'IPv6'
+					? `[${this.#address.address}]`
+					: this.#address.address;
+			return `http://${host}:${this.#address.port}${url}`;
+		}
+		// Fallback when the server address was not available at module
+		// load time (e.g. an adapter's dep optimizer pre-bundled the
+		// font runtime before the HTTP server started listening, #17722).
+		if (requestUrl) {
+			return `${requestUrl.origin}${url}`;
 		}
-		const host =
-			this.#address.family === 'IPv6' ? `[${this.#address.address}]` : this.#address.address;
-		return `http://${host}:${this.#address.port}${url}`;
+		throw new Error('Server address unavailable, this should not happen. Open an issue.');
 	}
 }

packages/astro/test/units/assets/fonts/infra.test.ts

@@ -783,7 +783,7 @@ describe('fonts infra', () => {
 				address: { address: '127.0.0.1', family: 'IPv4', port: 3000 },
 			});
 
-			assert.equal(resolver.resolve('/_astro/fonts/bar.woff2'), null);
+			assert.equal(resolver.resolve('/_astro/fonts/bar.woff2', undefined), null);
 		});
 
 		it('works with ipv4', () => {
@@ -793,7 +793,7 @@ describe('fonts infra', () => {
 			});
 
 			assert.equal(
-				resolver.resolve('/test/_astro/fonts/foo.woff2'),
+				resolver.resolve('/test/_astro/fonts/foo.woff2', undefined),
 				'http://127.0.0.1:3000/test/_astro/fonts/foo.woff2',
 			);
 		});
@@ -805,7 +805,7 @@ describe('fonts infra', () => {
 			});
 
 			assert.equal(
-				resolver.resolve('/_astro/fonts/foo.woff2'),
+				resolver.resolve('/_astro/fonts/foo.woff2', undefined),
 				'http://[::]:3000/_astro/fonts/foo.woff2',
 			);
 		});
@@ -817,10 +817,37 @@ describe('fonts infra', () => {
 			});
 
 			assert.equal(
-				resolver.resolve('http://cdn.example.com/_astro/fonts/foo.woff2'),
+				resolver.resolve('http://cdn.example.com/_astro/fonts/foo.woff2', undefined),
 				'http://127.0.0.1:3000/_astro/fonts/foo.woff2',
 			);
 		});
+
+		it('falls back to requestUrl when address is null', () => {
+			const resolver = new RemoteRuntimeFontFileUrlResolver({
+				urls: new Set(['/_astro/fonts/foo.woff2']),
+				address: null,
+			});
+
+			assert.equal(
+				resolver.resolve(
+					'/_astro/fonts/foo.woff2',
+					new URL('http://localhost:4321/og.png'),
+				),
+				'http://localhost:4321/_astro/fonts/foo.woff2',
+			);
+		});
+
+		it('returns full url directly when address is null and url is absolute (assetsPrefix)', () => {
+			const resolver = new RemoteRuntimeFontFileUrlResolver({
+				urls: new Set(['http://cdn.example.com/_astro/fonts/foo.woff2']),
+				address: null,
+			});
+
+			assert.equal(
+				resolver.resolve('http://cdn.example.com/_astro/fonts/foo.woff2', undefined),
+				'http://cdn.example.com/_astro/fonts/foo.woff2',
+			);
+		});
 	});
 
 	describe('SsrRuntimeFontFileUrlResolver', () => {