Describe the bug

To manage well the bundle, I am setting the packages into manualChunks e.g.:

The package fabric is used only in the admin area of my app, that is why I don't need it to be loaded directly in the front page.

If I don't set it in manualChunks, it works good and it will not be loaded in the front page, but my chunks then are too large, because vite place it automatically together with others in a huge backend chunk. Then as soon I open the backend it lazy loads all the other chunks, including the one that contains fabric. So this is the expected behavior.

If I set it in manualChunks, e.g.:

    rollupOptions: {
      output: {
        manualChunks: {
          fabric: ['fabric'],
        }
     }
   }

the fabric chunk is loaded directly on the front page. Even if I am not admin.

You can see the differences when I include fabric or not:

Not included in manualChunks

Included in manualChunks:

Expected behavior is: fabric should only be loaded when really used, else it creates only network traffic and lowers the Lighthouse score because of unused code!

NOTE: I am using an example with fabric here, but in my project I have a bunch of other libraries that have the same issue with manualChunks.

Reproduction

I created a small reproduction in this repo:

https://github.com/a-tonchev/react-boilerplate/tree/vite_no_lazy_load

Steps to reproduce:

1. Install deps (yarn)

Try bug:

1. yarn build && yarn serve
2. Open localhost:4000 and see in Network -> JS, the fabric script is loaded

To try without, open vite.config.js:
https://github.com/a-tonchev/react-boilerplate/blob/vite_no_lazy_load/vite.config.js

and comment out line 40

1. yarn build && yarn serve
2. Open localhost:4000 and see in Network -> JS, the fabric script is no more loaded,

System Info

Windows 10 + WSL (Ubuntu)

Vite version "^2.3.8"

Used Package Manager

yarn

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.