Fix hoisting of empty @layer statements that follow layer blocks

[madogiwa0124]

Problem

An empty @layer name; statement that comes after @layer name { ... } blocks is moved to the top of the bundle, which changes the cascade layer order.

/* pkg.css */
@layer base { html { box-sizing: border-box; } }
@layer utils { .hidden { display: none; } }
@layer overrides;

/* app.css */
@import "./pkg.css";
@layer overrides { body { background-color: #e5e5e5; } }

Output before this change:

@layer overrides;
@layer base { ... }
@layer utils { ... }
@layer overrides { body { background-color: #e5e5e5; } }

overrides now appears first, so it gets the lowest priority instead of the highest.

Cause

In lib/parse-statements.js, encounteredNonImportNodes was only set in the else branch for non at-rule nodes. At-rules that don't become a statement (such as @layer name { ... }, @media, @font-face) never set the flag. A later empty @layer name; was still seen as part of the import prelude, classified as a layer statement, and put in beforeBundle.

Fix

Set encounteredNonImportNodes for any non-comment node that does not become an import / charset / layer statement. Empty @layer statements before @import (the case fixed in #574 for #567) are handled the same as before.

Tests

• Added the layer-empty-after-content fixture. It fails without this change and passes with it.
• npm test: 87 tests pass.
• CI passes on my fork (Node 22.x, 24.x, 26.x): https://github.com/madogiwa0124/postcss-import/actions/runs/37122693036

🤖 Generated with Claude Code

[RyanZim]

I believe this looks correct, but would love to have a second review here @romainmenke.

[romainmenke]

Yes the fix is good :)

I also added some tests in https://github.com/romainmenke/css-import-tests to verify but hadn't yet gotten around to reporting back here.

Thank you @madogiwa0124