fix: dispose Cloudflare platform proxy when Vite servers close

.changeset/fresh-workers-retire.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-cloudflare': patch
+---
+
+fix: dispose Cloudflare platform proxies when Vite servers close

packages/adapter-cloudflare/index.js

@@ -219,18 +219,46 @@ export default function (options = {}) {
  * @returns {Plugin}
  */
 function virtual_workers_module(options, stub_import) {
+	/** @type {import('wrangler').PlatformProxy | undefined} */
+	let proxy;
+
 	const setup = async () => {
 		if (globalThis.__sveltekit_cloudflare_platform) return;
-		const proxy = await getPlatformProxy(options);
+		proxy = await getPlatformProxy(options);
 		// We store the platform proxy on globalThis so that our virtual workers module
 		// can access the same instance that we use here to populate `caches` and `cf` (above).
 		globalThis.__sveltekit_cloudflare_platform = proxy;
 		/** @type {any} */ (globalThis).caches = proxy.caches;
 	};
+
+	const dispose = async () => {
+		if (!proxy) return;
+
+		const current = proxy;
+		proxy = undefined;
+		if (globalThis.__sveltekit_cloudflare_platform === current) {
+			// @ts-expect-error allow another dev or preview server to create a new proxy
+			globalThis.__sveltekit_cloudflare_platform = undefined;
+		}
+		await current.dispose();
+	};
+
 	return {
 		name: 'vite-plugin-sveltekit-adapter-cloudflare-virtual-workers-module',
 		configureServer: setup,
-		configurePreviewServer: setup,
+		async configurePreviewServer(server) {
+			await setup();
+
+			const close = server.close;
+			server.close = async () => {
+				try {
+					await close.call(server);
+				} finally {
+					await dispose();
+				}
+			};
+		},
+		closeBundle: dispose,
 		resolveId: {
 			filter: { id: exactRegex('cloudflare:workers') },
 			handler() {

packages/adapter-cloudflare/index.spec.js

@@ -0,0 +1,59 @@
+import { afterEach, beforeEach, describe, expect, test, vi } from 'vitest';
+import { getPlatformProxy } from 'wrangler';
+import adapter from './index.js';
+
+vi.mock('wrangler', () => ({
+	getPlatformProxy: vi.fn(),
+	unstable_readConfig: vi.fn()
+}));
+
+/** @type {Awaited<ReturnType<typeof getPlatformProxy>> | undefined} */
+let proxy;
+
+beforeEach(() => {
+	const value = /** @type {Awaited<ReturnType<typeof getPlatformProxy>>} */ (
+		/** @type {unknown} */ ({
+			env: {},
+			ctx: {},
+			caches: {},
+			cf: {},
+			dispose: vi.fn()
+		})
+	);
+	proxy = value;
+	vi.mocked(getPlatformProxy).mockResolvedValue(value);
+});
+
+afterEach(() => {
+	// @ts-expect-error reset the global populated by the plugin
+	globalThis.__sveltekit_cloudflare_platform = undefined;
+});
+
+describe('virtual workers module', () => {
+	test('disposes the platform proxy when the dev server closes', async () => {
+		const plugin = adapter().vite?.plugins?.pre?.[0];
+		const configure_server = /** @type {Function} */ (plugin?.configureServer);
+		const close_bundle = /** @type {Function} */ (plugin?.closeBundle);
+
+		await configure_server({});
+		await close_bundle();
+		await close_bundle();
+
+		expect(proxy?.dispose).toHaveBeenCalledOnce();
+		expect(globalThis.__sveltekit_cloudflare_platform).toBeUndefined();
+	});
+
+	test('disposes the platform proxy when the preview server closes', async () => {
+		const plugin = adapter().vite?.plugins?.pre?.[0];
+		const configure_preview_server = /** @type {Function} */ (plugin?.configurePreviewServer);
+		const close = vi.fn();
+		const server = { close };
+
+		await configure_preview_server(server);
+		await server.close();
+
+		expect(close).toHaveBeenCalledOnce();
+		expect(proxy?.dispose).toHaveBeenCalledOnce();
+		expect(globalThis.__sveltekit_cloudflare_platform).toBeUndefined();
+	});
+});

packages/adapter-cloudflare/tsconfig.json

@@ -17,6 +17,7 @@
 	},
 	"include": [
 		"index.js",
+		"index.spec.js",
 		"src",
 		"utils.js",
 		"utils.spec.js",