CSS default import warning appears for pre-bundled dependencies even if the import is unused

[caghand]

Describe the bug

#11094 added a warning for importing the default export of a CSS file.
Then, #11121 disabled this warning when the default import of a CSS file is not used.
However, the warning still exists for pre-bundled dependencies where the default import is not used.

Reproduction

https://stackblitz.com/edit/vitejs-vite-juhqxl?file=main.js

Steps to reproduce

Look at this line in the vott-ct package: https://github.com/microsoft/CanvasTools-for-VOTT/blob/master/src/canvastools/ts/ct.ts#L86
The transpiled code in the npm package looks like this:
require("./../css/canvastools.css");
Then, the dependency pre-bundling step (optimizeDeps) translates it to the following block:

// vite:dep-pre-bundle:external-conversion:D:/<path_to_project>/node_modules/vott-ct/lib/css/canvastools.css
var canvastools_exports = {};
__export(canvastools_exports, {
  default: () => default2
});
import { default as default2 } from "D:/<path_to_project>/node_modules/vott-ct/lib/css/canvastools.css";
import * as canvastools_star from "D:/<path_to_project>/node_modules/vott-ct/lib/css/canvastools.css";
var init_canvastools = __esm({
  "vite:dep-pre-bundle:external-conversion:D:/<path_to_project>/node_modules/vott-ct/lib/css/canvastools.css"() {
    init_esbuildNodeGlobals();
    __reExport(canvastools_exports, canvastools_star);
  }
});

Then, when importing from vott-ct, we see the following warnings in dev mode:

9:28:35 PM [vite] warning:
D:/<path_to_project>/node_modules/.vite/deps/vott-ct.js
5462|    default: () => default2
5463|  });
5464|  import { default as default2 } from "D:/<path_to_project>/node_modules/vott-ct/lib/css/canvastools.css";
   |                                       ^
5465|  import * as canvastools_star from "D:/<path_to_project>/node_modules/vott-ct/lib/css/canvastools.css";
5466|  var init_canvastools = __esm({
Default and named imports from CSS files are deprecated. Use the ?inline query instead. For example: import { default as default2 } from "D:/<path_to_project>/node_modules/vott-ct/lib/css/canvastools.css?inline"
  Plugin: vite:import-analysis
  File: D:/<path_to_project>/node_modules/.vite/deps/vott-ct.js?v=09e38d5f
9:28:35 PM [vite] warning:
D:/<path_to_project>/node_modules/.vite/deps/vott-ct.js
5463|  });
5464|  import { default as default2 } from "D:/<path_to_project>/node_modules/vott-ct/lib/css/canvastools.css";
5465|  import * as canvastools_star from "D:/<path_to_project>/node_modules/vott-ct/lib/css/canvastools.css";
   |                                     ^
5466|  var init_canvastools = __esm({
5467|    "vite:dep-pre-bundle:external-conversion:D:/<path_to_project>/node_modules/vott-ct/lib/css/canvastools.css"() {
Default and named imports from CSS files are deprecated. Use the ?inline query instead. For example: import * as canvastools_star from "D:/<path_to_project>/node_modules/vott-ct/lib/css/canvastools.css?inline"
  Plugin: vite:import-analysis
  File: D:/<path_to_project>/node_modules/.vite/deps/vott-ct.js?v=09e38d5f

System Info

System:
    OS: Windows 10 10.0.22000
    CPU: (16) x64 Intel(R) Xeon(R) Platinum 8370C CPU @ 2.80GHz
    Memory: 32.63 GB / 63.95 GB
  Binaries:
    Node: 14.20.0 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.21.1 - D:\<path_to_project>\node_modules\.bin\yarn.CMD
    npm: 6.14.17 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Edge: Spartan (44.22000.120.0), Chromium (110.0.1587.57)
    Internet Explorer: 11.0.22000.120
  npmPackages:
    @vitejs/plugin-basic-ssl: ^1.0.1 => 1.0.1
    @vitejs/plugin-react: ^3.1.0 => 3.1.0
    vite: ^4.1.4 => 4.1.4

Used Package Manager

yarn

Logs

No response

Validations

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

[stackblitz]

Start a new pull request in StackBlitz Codeflow.

• vitejs-vite-juhqxl (Open reproduction)

[sun0day]

I think this works as expected cause canvastools_star is used to reexport even though import VottTest from 'vott-ct'; hasn't been used.

In the meantime, directly importing unused default CSS shouldn't show this warning. @sapphi-red

[caghand]

Yes, I understand that the warning is shown because of canvastools_star.
But, to be precise, this issue is unrelated to whether import VottTest from 'vott-ct'; is used or not.
Rather, it's about this: If the dependency has something like require("./../css/canvastools.css");, then the pre-bundled (optimized) version (with canvastools_star) should not produce the warning. Maybe by optimizing the code in a different way (without canvastools_star), or maybe by suppressing the warning somehow..?

[caghand]

Thanks a lot, @sun0day and @sapphi-red!