rollup-plugin-multi-entry (virtual) does not work with dev server

[Natureshadow]

Describe the bug

We have a Vite project that must pull together code from several entry scripts into one entry chunk, and are using rollup-plugin-multi-entry to achieve this. That in turn uses rollup-plugin-virtual.

Vite config:

const fs = require("fs");
const path = require("path");

import { defineConfig } from "vite";
import vue from "@vitejs/plugin-vue2";
import { nodeResolve } from "@rollup/plugin-node-resolve";
import graphql from "@rollup/plugin-graphql";
import multi from '@rollup/plugin-multi-entry';

export default defineConfig({
  base: "/static",
  build: {
    outDir: path.resolve("./vite_bundles/"),
    manifest: true,
    rollupOptions: {
      input: ["aleksis/core/assets/index.js", "aleksis/core/assets/foo.js"],
    },
  },
  server: {
    strictPort: true,
    origin: "http://127.0.0.1:5173",
  },
  plugins: [
    multi({entryFileName: "aleksis-local-full.js"}),
    vue(),
    nodeResolve({ modulePaths: [path.resolve("./node_modules")] }),
    graphql(),
  ],
  resolve: {
    alias: {
      vue: "vue/dist/vue.esm.js",
    },
  },
});

Now, when building for production, this generates the following manifest snippet:

  "virtual:aleksis-local-full.js": {
    "file": "aleksis-local-full.js",
    "src": "virtual:aleksis-local-full.js",
    "isEntry": true,
    "css": [
      "assets/_virtual_aleksis-local-full-807696e7.css"
    ],
    "assets": [
      "assets/materialdesignicons-webfont-5be9e9d7.eot",
      "assets/materialdesignicons-webfont-633d596f.woff2",
      "assets/materialdesignicons-webfont-7f3afe9b.woff",
      "assets/materialdesignicons-webfont-948fce52.ttf"
    ]
  },
  "\u0000virtual:aleksis-local-full.css": {
    "file": "assets/_virtual_aleksis-local-full-807696e7.css",
    "src": "\u0000virtual:aleksis-local-full.css"
  }

Note how one is prefixed with only virtual and one with \u000virtual. This is strange, but in production, it works.

When running the dev server, however, it fails to resolve /static/virtual:aleksis-local-full.js and throws a 404 error.

My current guess is that rollup-plugin-virtual always expects the \0virtual prefix including the NULL byte, and thus, in the dev server, resolving the bundle name without the NULL byte fails. So the issue here would be that some code parts include the NULL byte and some don't.

Reproduction

https://github.com/Natureshadow/vite-multi-mwe

Steps to reproduce

Run npm install and npm run dev, then try to access http://localhost:5173/virtual:multi-entry.js.

System Info

System:
    OS: Linux 6.0 Debian GNU/Linux bookworm/sid
    CPU: (8) x64 Intel(R) Core(TM) i7-8665U CPU @ 1.90GHz
    Memory: 8.85 GB / 15.26 GB
    Container: Yes
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 18.12.1 - /usr/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 9.2.0 - /usr/bin/npm
  Browsers:
    Chromium: 108.0.5359.124
    Firefox: 108.0
  npmPackages:
    vite: ^4.0.0 => 4.0.2

Used Package Manager

npm

Logs

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[Natureshadow]

OK, so, manifest generation strips off the NULL character for all bundles: https://github.com/vitejs/vite/blob/main/packages/vite/src/node/plugins/manifest.ts#L45

And it seems to be intended that when using the dev server, the NULL character must be passed in the URL as well (how strange is that)?

So the problem boils down to the expected bundle names discovered from the manifest and expected by the dev server are asymmetric.

[bluwy]

Related: #6225

[frederikbosch]

@Natureshadow were you able to somehow access virtual files with the dev server?

[Natureshadow]

I... honestly, I don't remember anymore :D. @hansegucker do you know how this ended up?

[hansegucker]

@hansegucker do you know how this ended up?

I also don't remember right away. I will have to take another look.