[BUG] CSS Modules support broken in 3.3.3

[sminnee]

Describe the bug

The JSON payload of CSS modules is empty in 3.3.3+

I've downloiaded

It seems to be this commit 8329444

To Reproduce

Run snowpack with a module

/** block.module.css *.
:root {
  --some-color: red;
}

.edit {
  color: var(--some-color);
  font: sans-serif;
  width: 100%;
}

.view {
  color: var(--some-color);
  font: sans-serif;
  width: 100%;
}

Import in a JS file

Observe the block.modules.css.proxy.js content:

export let code = ".__edit_162wa_5_10gxy_1 {\n  color: red;\n  font: sans-serif;\n  width: 100%;\n}\n\n.__view_162wa_11_10gxy_7 {\n  color: red;\n  font: sans-serif;\n  width: 100%;\n}\n";
let json = {};
export default json;

import * as __SNOWPACK_HMR_API__ from '/_snowpack/hmr-client.js';
import.meta.hot = __SNOWPACK_HMR_API__.createHotContext(import.meta.url);

// [snowpack] add styles to the page (skip if no document exists)
if (typeof document !== 'undefined') {
  import.meta.hot.dispose(() => {
    document && document.head.removeChild(styleEl);
  });

  const styleEl = document.createElement("style");
  const codeEl = document.createTextNode(code);
  styleEl.type = 'text/css';

  styleEl.appendChild(codeEl);
  document.head.appendChild(styleEl);
}

let json should have a value.

Confirm that it works in 3.3.2

let json = {"edit":"_edit_1fmvc_5","view":"_view_1fmvc_11"};
export default json;

[drwpow]

Thanks for filing. Yes behavior of CSS Modules did change in that commit as stated, but tests were added to test this exact behavior: https://github.com/snowpackjs/snowpack/blob/main/test/snowpack/cssModules/index.test.js#L148, and they’re currently passing. Are you able to provide a reproduction of this bug, or add a failing test in the Snowpack repo itself?

[drwpow]

Actually this seems to be a duplicate of #3219

[drwpow]

Bug should be fixed as of v3.3.6! 🎉 Thank you for filing.

[sminnee]

Thanks! One thing I noticed today was that your experimental module combiner had a similar bug. I'll see if it's fixed in 3.3.6.

[sminnee]

FYI I noted on #2998 that both ESbuild and Webpack bundling fail to handle CSS modules in 3.8.8.