Reproduction link or steps

Here is the minimal repro: https://github.com/alfeg/rolldown-init-bug-repro

What is expected?

For every chunk that contains an init_X() call, the dep optimizer should
also emit the corresponding cross-chunk import binding for init_X — the
same way it does for the sibling chunks @vue/server-renderer,
vue.runtime.esm-bundler, and compiler-dom.esm-bundler, which all
correctly import v as init_shared_esm_bundler from
shared.esm-bundler-*.js.

What is actually happening?

The pre-bundled @vue/test-utils chunk emits the call but the import is
dropped. First lines of node_modules/.vite/vitest/<hash>/deps/@vue_test-utils.js:

import { …, n as vue_runtime_esm_bundler_exports, … } from "./vue.runtime.esm-bundler-XXXX.js";
import { h as compile } from "./compiler-dom.esm-bundler-XXXX.js";
import { renderToString as renderToString$1 } from "./@vue_server-renderer.js";
//#region node_modules/@vue/test-utils/dist/vue-test-utils.esm-bundler.mjs
init_shared_esm_bundler();   // ← never imported → ReferenceError at load

System Info

❯ npx envinfo --system --npmPackages rolldown --binaries --browsers
Need to install the following packages:
envinfo@7.21.0
Ok to proceed? (y) y

  System:
    OS: Windows 11 10.0.28000
    CPU: (16) x64 AMD Ryzen 7 7800X3D 8-Core Processor           
    Memory: 21.29 GB / 63.16 GB
  Binaries:
    Node: 24.15.0 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.22.19 - C:\Program Files\nodejs\yarn.CMD
    npm: 11.11.0 - C:\Program Files\nodejs\npm.CMD
    pnpm: 9.6.0 - C:\Program Files\nodejs\pnpm.CMD
    bun: 1.3.0 - C:\Users\Victo\.bun\bin\bun.EXE
    Deno: 2.6.4 - C:\Users\Victo\.deno\bin\deno.EXE
  Browsers:
    Chrome: 148.0.7778.168
    Edge: Chromium (146.0.3856.97)
    Firefox: 150.0.3 - C:\Program Files\Mozilla Firefox\firefox.exe

Any additional comments?

• Two conditions both seem required to trigger the miswire:
  1. @vue/compiler-dom is split into a CJS-interop sub-chunk
     (compiler-dom.esm-bundler-<hash>.js with __commonJSMin /
     require_compiler_core_cjs()). Vitest's optimizer pass uses
     mainFields: [] and drops module from resolve conditions, so
     @vue/compiler-core resolves via its node export → CJS.
  2. The consumer chunk's source has a namespace import:
     import * as Vue from "vue". The other consumers use only named
     imports and their init_shared_esm_bundler import is wired correctly.
• Downstream impact: every Vitest browser-mode test suite using
  @vue/test-utils under Vite 8 crashes at startup, because
  @vitest/browser auto-adds @vue/test-utils to optimizeDeps.include.

Created with the help of LLM tools