CSS variables with same value defined in media query are minified incorrectly

[CLDXiang]

esbuild@0.17.0

When two different CSS variables with same value defined in media query, only one of these CSS variables will remain in the minified output.

Input:

@media (prefers-color-scheme: dark) {
  body {
    --VAR-1: #000;
  }
}

@media (prefers-color-scheme: dark) {
  body {
    --VAR-2: #000;
  }
}

esbuild --bundle style.css --outfile=out.css --minify-syntax output:

/* style.css */
@media (prefers-color-scheme: dark) {
  body {
    --VAR-2: #000;
  }
}

[evanw]

Thanks for the report. It looks like this is an old regression from version 0.11.19.

Edit: And it was caused by a dumb typo: RulesEqual(a.Rules, a.Rules) instead of RulesEqual(a.Rules, b.Rules).