css-minifier: CSS custom properties in @supports cannot remove spaces

[yisibl]

@supports (--foo:    ) {
      html { background: green; }
}

esbuild --minify output:

@supports (--foo:){html{background:green}}

Expectation

Browser page shows green background.
After compression, keep at least one space after --foo: , otherwise not valid in Chrome.

See also: https://lea.verou.me/2020/10/the-var-space-hack-to-toggle-multiple-values-with-one-custom-property/

[evanw]

That's strange. Both Firefox and Safari treat these two examples the same while Chrome only respects the first one. I wonder if this is a bug with Chrome or with both Firefox and Safari. I'll work on a fix.

[yisibl]

That's strange. Both Firefox and Safari treat these two examples the same while Chrome only respects the first one. I wonder if this is a bug with Chrome or with both Firefox and Safari. I'll work on a fix.

Waiting for answers from CSS experts: https://twitter.com/yisibl/status/1494143919441195011