fix(vite-plugin-cloudflare): ensure cross-process service bindings route through asset worker (#9556)

Author: edmundhung

.changeset/eight-buckets-bathe.md

@@ -0,0 +1,5 @@
+---
+"@cloudflare/vite-plugin": patch
+---
+
+fix: cross-process service bindings no longer skip static asset serving

.changeset/icy-lands-build.md

@@ -0,0 +1,7 @@
+---
+"miniflare": minor
+---
+
+Added a `serviceName` option to `unsafeDirectSockets`
+
+This allows registering the current worker in the dev registry under its own name, but routing to a different service.

fixtures/dev-registry/assets/example.txt

@@ -0,0 +1 @@
+This is an example asset file

fixtures/dev-registry/tests/dev-registry.test.ts

@@ -51,8 +51,8 @@ describe("Dev Registry: vite dev <-> vite dev", () => {
 	it("supports module worker fetch over service binding", async ({
 		devRegistryPath,
 	}) => {
-		const workerEntrypointA = await runViteDev(
-			"vite.worker-entrypoint-a.config.ts",
+		const workerEntrypointB = await runViteDev(
+			"vite.worker-entrypoint-b.config.ts",
 			devRegistryPath
 		);
 
@@ -62,7 +62,7 @@ describe("Dev Registry: vite dev <-> vite dev", () => {
 				"test-service": "module-worker",
 				"test-method": "fetch",
 			});
-			const response = await fetch(`${workerEntrypointA}?${searchParams}`);
+			const response = await fetch(`${workerEntrypointB}?${searchParams}`);
 
 			expect(response.status).toBe(503);
 			expect(await response.text()).toEqual(
@@ -78,13 +78,21 @@ describe("Dev Registry: vite dev <-> vite dev", () => {
 		// Test module-worker -> worker-entrypoint
 		await vi.waitFor(async () => {
 			const searchParams = new URLSearchParams({
-				"test-service": "worker-entrypoint-a",
+				"test-service": "worker-entrypoint-b",
 				"test-method": "fetch",
 			});
 			const response = await fetch(`${moduleWorker}?${searchParams}`);
 
 			expect(await response.text()).toBe("Hello from Worker Entrypoint!");
 			expect(response.status).toBe(200);
+
+			// Test fetching asset from "worker-entrypoint-b" over service binding
+			// Module worker has no assets, so it will hit the user worker and
+			// forward the request to "worker-entrypoint-b" with the asset path
+			const assetResponse = await fetch(
+				`${moduleWorker}/example.txt?${searchParams}`
+			);
+			expect(await assetResponse.text()).toBe("This is an example asset file");
 		});
 
 		// Test worker-entrypoint -> module-worker
@@ -93,7 +101,7 @@ describe("Dev Registry: vite dev <-> vite dev", () => {
 				"test-service": "module-worker",
 				"test-method": "fetch",
 			});
-			const response = await fetch(`${workerEntrypointA}?${searchParams}`);
+			const response = await fetch(`${workerEntrypointB}?${searchParams}`);
 
 			expect(await response.text()).toEqual("Hello from Module Worker!");
 			expect(response.status).toBe(200);

fixtures/dev-registry/vite.worker-entrypoint-b.config.ts

@@ -2,6 +2,9 @@ import { cloudflare } from "@cloudflare/vite-plugin";
 import { defineConfig } from "vite";
 
 export default defineConfig({
+	// Override the default public directory to use the assets directory
+	// so that other vite projects won't share the same assets
+	publicDir: "./assets",
 	plugins: [
 		cloudflare({
 			configPath: "./wrangler.worker-entrypoint-b.jsonc",

fixtures/dev-registry/wrangler.service-worker.jsonc

@@ -1,4 +1,5 @@
 {
+	"$schema": "node_modules/wrangler/config-schema.json",
 	"name": "service-worker",
 	"main": "./workers/service-worker.ts",
 	"compatibility_date": "2025-05-01",

fixtures/dev-registry/wrangler.worker-entrypoint-a.jsonc

@@ -1,4 +1,5 @@
 {
+	"$schema": "node_modules/wrangler/config-schema.json",
 	"name": "worker-entrypoint-a",
 	"main": "./workers/worker-entrypoint.ts",
 	"compatibility_date": "2025-05-01",

fixtures/dev-registry/wrangler.worker-entrypoint-b.jsonc

@@ -1,7 +1,11 @@
 {
+	"$schema": "node_modules/wrangler/config-schema.json",
 	"name": "worker-entrypoint-b",
 	"main": "./workers/worker-entrypoint.ts",
 	"compatibility_date": "2025-05-01",
+	"assets": {
+		"directory": "./assets",
+	},
 	"services": [
 		{
 			"binding": "SERVICE_WORKER",

packages/miniflare/src/index.ts

@@ -1819,6 +1819,7 @@ export class Miniflare {
 			for (let j = 0; j < directSockets.length; j++) {
 				const previousDirectSocket = previousDirectSockets[j];
 				const directSocket = directSockets[j];
+				const serviceName = directSocket.serviceName ?? workerName;
 				const entrypoint = directSocket.entrypoint ?? "default";
 				const name = getDirectSocketName(i, entrypoint);
 				const address = this.#getSocketAddress(
@@ -1835,7 +1836,7 @@ export class Miniflare {
 								name: `${RPC_PROXY_SERVICE_NAME}:${workerOpts.core.name}`,
 							}
 						: {
-								name: getUserServiceName(workerName),
+								name: getUserServiceName(serviceName),
 								entrypoint: entrypoint === "default" ? undefined : entrypoint,
 							};
 

packages/miniflare/src/plugins/core/index.ts

@@ -118,6 +118,7 @@ const UnusableStringSchema = z.string().transform(() => undefined);
 export const UnsafeDirectSocketSchema = z.object({
 	host: z.ostring(),
 	port: z.onumber(),
+	serviceName: z.ostring(),
 	entrypoint: z.ostring(),
 	proxy: z.oboolean(),
 });