Optimizing properties of level 2 removes hsl values

Precheck

Using 2 level, color values specified in hsl format are removed.

Similar to https://github.com/clean-css/clean-css/issues/1156

Environment

• clean-css version - 5.1.5
• node.js version - 14.17.5
• operating system - Linux 5.13.12

Configuration options

var CleanCSS = require('clean-css');
new CleanCSS({ inline: false, level: 2 })

Input CSS

.zone.contacts .size_1_3 > a {
      border: 3px solid hsl(0deg 0 85%);
}

Actual output CSS

.zone.contacts .size_1_3>a{border:3px solid}

Expected output CSS

.zone.contacts .size_1_3>a{border:3px solid hsl(0deg 0 85%)}

[jakubpawlowicz]

Thanks, I’ll dig into it.

[boris-petrov]

Not sure about that, probably it is OK to not use percentage as in most places CSS accepts also zero without a unit.

Also, here are more examples that are removed:

.foo {
  border-top: 0.063rem solid hsl(210deg, 10%, 24%);
}

.foo {
  border-top: 0.063rem solid hsl(210deg, 10.8108108108%, 24.649859944%);
}