fix(deploy): keep framework Worker Wasm imports as Wasm modules

packages/void/src/cli/cf-build-output.ts

@@ -1,3 +1,4 @@
+import { createHash } from 'node:crypto';
 import {
   cpSync,
   copyFileSync,
@@ -26,6 +27,7 @@ import {
 import { type ModuleType, OutputContainerSchema } from '@cloudflare/config';
 import ignore from 'ignore';
 import { basename, dirname, extname, isAbsolute, join, relative, resolve } from 'pathslash';
+import type { Plugin } from 'vite';
 import { migrateBuiltWranglerConfig, record } from './cf-config-migrate.ts';
 import { buildContainerImage } from './container-image.ts';
 import { readGeneratedWranglerConfigFile } from './generated-wrangler-config.ts';
@@ -321,6 +323,28 @@ async function prepareNativeBuildOutput(
   }
 }
 
+/** Emit `.wasm` imports beside the bundle so cf uploads them as Worker Wasm modules. */
+function workerWasmModules(): Plugin {
+  return {
+    name: 'void:worker-wasm-modules',
+    enforce: 'pre',
+    async resolveId(source, importer) {
+      if (!source.endsWith('.wasm')) {
+        return null;
+      }
+      const resolved = await this.resolve(source, importer, { skipSelf: true });
+      if (!resolved) {
+        return null;
+      }
+      const wasm = readFileSync(resolved.id);
+      const hash = createHash('sha256').update(wasm).digest('hex').slice(0, 8);
+      const fileName = `${basename(resolved.id, '.wasm')}-${hash}.wasm`;
+      this.emitFile({ type: 'asset', fileName, source: wasm });
+      return { id: `./${fileName}`, external: true };
+    },
+  };
+}
+
 /** Bundle a generated Worker entry with Vite, then hand the result to `prepareCfBuildOutput`. */
 async function prepareBundledBuildOutput(options: {
   projectRoot: string;
@@ -339,6 +363,7 @@ async function prepareBundledBuildOutput(options: {
       root: options.projectRoot,
       publicDir: false,
       logLevel: 'error',
+      plugins: [workerWasmModules()],
       build: {
         outDir: scratch,
         emptyOutDir: true,

packages/void/test/unit/cf-build-output.test.ts

@@ -562,6 +562,73 @@ it(
   CF_BUILD_TIMEOUT_MS,
 );
 
+it(
+  'keeps framework Wasm imports as Worker Wasm modules',
+  async () => {
+    const root = mkdtempSync(join(tmpdir(), 'void-cf-framework-wasm-test-'));
+    roots.push(root);
+    const output = join(root, 'framework');
+    mkdirSync(join(output, 'chunks'), { recursive: true });
+    writeFileSync(join(root, 'package.json'), JSON.stringify({ type: 'module' }));
+    writeFileSync(
+      join(root, 'wrangler.json'),
+      JSON.stringify({
+        name: 'void-framework-test',
+        account_id: 'account-id',
+        main: 'framework/_worker.js',
+        compatibility_date: '2026-09-29',
+        assets: { directory: 'framework', binding: 'ASSETS' },
+      }),
+    );
+    // Imports `wbg`, like wasm-bindgen output.
+    const bindgenWasm = Buffer.from([
+      0, 97, 115, 109, 1, 0, 0, 0, 1, 4, 1, 96, 0, 0, 2, 9, 1, 3, 119, 98, 103, 1, 102, 0, 0,
+    ]);
+    const plainWasm = Buffer.from([0, 97, 115, 109, 1, 0, 0, 0]);
+    mkdirSync(join(root, 'node_modules/bindgen'), { recursive: true });
+    writeFileSync(join(root, 'node_modules/bindgen/index_bg.wasm'), bindgenWasm);
+    writeFileSync(join(output, 'plain.wasm'), plainWasm);
+    writeFileSync(
+      join(output, '_worker.js'),
+      "import plain from './plain.wasm'; import { render } from './chunks/render.js';\n" +
+        'export default { async fetch() { return new Response(String(plain) + await render()) } };\n',
+    );
+    writeFileSync(
+      join(output, 'chunks/render.js'),
+      "import plain from '../plain.wasm';\n" +
+        "export async function render() { return String(plain) + String(await import('bindgen/index_bg.wasm')); }\n",
+    );
+    writeFileSync(join(output, '.assetsignore'), '_worker.js\n');
+
+    await withPrepared(
+      prepareCfFrameworkBuildOutput({
+        projectRoot: root,
+        configPath: join(root, 'wrangler.json'),
+        accountId: 'account-id',
+      }),
+      async (prepared) => {
+        const built = await readBuildOutput(prepared.directory);
+        const modules = built.workers.default.config.manifest?.modules ?? {};
+        const wasm = Object.keys(modules).filter((name) => modules[name].type === 'wasm');
+        const bundle = getWorkerBundleDir(prepared.directory);
+        expect(wasm.map((name) => readFileSync(join(bundle, name)))).toEqual(
+          expect.arrayContaining([bindgenWasm, plainWasm]),
+        );
+        expect(wasm).toHaveLength(2);
+        const code = readdirSync(bundle)
+          .filter((name) => name.endsWith('.js'))
+          .map((name) => readFileSync(join(bundle, name), 'utf8'))
+          .join('\n');
+        for (const name of wasm) {
+          expect(code).toContain(`./${name}`);
+        }
+        expectCfDryRun(prepared.directory);
+      },
+    );
+  },
+  CF_BUILD_TIMEOUT_MS,
+);
+
 it(
   'accepts a nested hashed Worker entry with a relative module import',
   async () => {