Export runtime-vapor to support unit-test for Vapor Mode

Why this is a good first issue

Issue requests exporting a specific runtime module for testing purposes.

AI Summary

The issue reports that runtime-vapor is not exported from vue's cjs-bundler, causing test failures. The solution likely involves adding the export in the bundler configuration. The scope appears limited but requires knowledge of Vapor mode's runtime exports.

Issue Description

Vue version

3.6.0-beta.5

Link to minimal reproduction

https://github.com/zhiyuanzmj/router

Steps to reproduce

1 . git clone https://github.com/zhiyuanzmj/router -b vapor-issue 2. pnpm install && pnpm test

What is expected?

Export runtime-vapor from vue's cjs-bundler.

What is actually happening?

Will report a defineVaporComponent is not a function error

System Info

System:
    OS: macOS 26.2
    CPU: (10) arm64 Apple M1 Pro
    Memory: 129.38 MB / 16.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 23.8.0 - /usr/local/bin/node
    Yarn: 1.22.22 - /usr/local/bin/yarn
    npm: 10.9.2 - /usr/local/bin/npm
    pnpm: 10.28.2 - ~/Library/pnpm/pnpm
    bun: 1.3.6 - ~/.bun/bin/bun
  Browsers:
    Chrome: 144.0.7559.133
    Safari: 26.2

Any additional comments?

A temporary solution

// vitest.config.ts
export default defineConfig({
  // FIXME: shouldn't be needed
  resolve: {
    alias: {
      // cjs does not export vapor runtime, use esm instead.
      "@vue/runtime-core": require.resolve('@vue/runtime-core').replace('index.js', 'dist/runtime-core.esm-bundler.js'),
       "@vue/runtime-dom": require.resolve('@vue/runtime-dom').replace('index.js', 'dist/runtime-dom.esm-bundler.js'),
      vue: 'vue/dist/vue.runtime.esm-bundler.js',
    },
  },
})

Since runtime-vapor doesn't export from cjs-bundler. We must use vitest to alias vue as esm-bundler.

GitHub Labels

need discussionscope: vapor