@swc/plugin-emotion 14.8.0: keyframes label injection causes css-animation- class name prefix

[jvm986]

Describe the bug

@swc/plugin-emotion@14.8.0 injects "label:pulse;" into keyframes tagged template literal calls, whereas 14.7.0 correctly passes just the name string "pulse". This causes Emotion's runtime to generate CSS class names with an animation- prefix (e.g., css-animation-1k1d89d instead of css-1k1d89d), breaking styles in production builds.

The regression was introduced by PR #597, which changed create_label(false) to create_label(true) for tagged template expressions. Since keyframes is mapped to ExprKind::Css in import_map.rs, the label injection now also applies to keyframes calls — but keyframes expects a plain name string, not a label:name; CSS property.

14.7.0 output (correct):

var pulse = keyframes("0%{opacity:1;}50%{opacity:0.5;}100%{opacity:1;}", "pulse", "/*# sourceMappingURL=... */");

14.8.0 output (broken):

var pulse = keyframes("0%{opacity:1;}50%{opacity:0.5;}100%{opacity:1;}", "label:pulse;", "/*# sourceMappingURL=... */");

URL to minimal reproduction

https://gist.github.com/jvm986/1c5440e095c90f0fe09f81251f8570aa

pnpm install
node transform.mjs

Expected behavior

keyframes calls should receive the plain name string (e.g., "pulse"), not a CSS label property ("label:pulse;"). Class names should not contain animation- prefix.

Additional context

• @swc/plugin-emotion: 14.8.0 (works correctly on 14.7.0)
• @swc/core: 1.15.24
• @emotion/react: 11.14.0
• Regression introduced by fix(emotion): fix autoLabel not adding label to css tagged template class names #597