Worker output paths aren't respected in lib mode

[ivancuric]

Describe the bug

I am using a hacky approach to build a worker bundle in a lib mode.

It's not possible to configure the lib.formats option for every entry, and I need to configure it as an iife for the worker output. I am therefore forced to use Vite's worker loading.

Vite's worker extraction won't when a dynamic path is used, and I need a configurable path in my lib, like:

// this won't generate a worker bundle
export function loadWorker(url: string) {
  const worker = new Worker(new URL("./worker.ts", url));
}

To force the extraction, I am using an unreachable code path which will get stripped out:

// unreachable code for worker extraction
if (false) {
  new Worker(new URL("./worker.ts", import.meta.url));
}

I am now stuck in trying to move the worker bundle to a different folder.

worker: {
    format: "iife",
    rollupOptions: {
      output: {
		// this won't work
        assetFileNames: "resources/blinkid.worker.js",
      },
    },
  },

#7804 doesn't seem to have fully fixed worker rollup options.

Reproduction

https://stackblitz.com/edit/vitejs-vite-vpk6ws?file=vite.config.js&view=editor

Steps to reproduce

npm install && npm run build

System Info

System:
    OS: macOS 12.6.3
    CPU: (10) arm64 Apple M1 Pro
    Memory: 84.34 MB / 16.00 GB
    Shell: 5.8.1 - /bin/zsh
  Binaries:
    Node: 19.7.0 - ~/.nvm/versions/node/v19.7.0/bin/node
    Yarn: 1.22.19 - ~/.nvm/versions/node/v19.7.0/bin/yarn
    npm: 9.5.1 - ~/.nvm/versions/node/v19.7.0/bin/npm
  npmPackages:
    vite: ^4.1.4 => 4.1.4

Used Package Manager

pnpm

Logs

No response

Validations

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• Read the Contributing Guidelines.
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• The provided reproduction is a minimal reproducible example of the bug.

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Start a new pull request in StackBlitz Codeflow.

• vitejs-vite-vpk6ws (Open reproduction)

[xiaohk]

Same issue here. Did you find any workaround? @ivancuric

[xiaohk]

It seems the following config works:

worker: {
  format: 'es',
  rollupOptions: {
    output: {
      entryFileNames: '[name].js'
    }
  }
},

[mustafa0x]

entryFileNames does indeed work.

[sapphi-red]

In this case, worker.js is the entry file of the worker. So entryFileNames needs to be used instead of assetFileNames.