[Feature Request]: postcss-normalize-whitespace should fold whitespace within var()

[nex3]

What should be improved?

Currently, postcss-normalize-whitespace doesn't compress whitespace at all within var() function calls. For example, var( --foo ) is emitted as-is rather than as var(--foo) or var( --foo ).

Describe the solution you would like

Within a normal property, whitespace before the first comma in var() should be removed completely and whitespace after the first comma should be folded down to a single space or removed depending on the context of the var(). For example:

/* input */
a {
  b: var(
    --foo
  );
}

/* output */
a{b:var(--foo)}

Within a custom property, since it may be interpreted by JavaScript rather than CSS (see #1456), whitespace should be folded down to the smallest form that produces an equivalent serialization: a single space. For example:

/* input */
a {
  --b: var(
    --foo
  );
}

/* output */
a{--b: var( --foo )}

Possible alternatives

No response

Additional context

N/A

Are you willing to work on this?

• Yes, I would like to help

[ludofischer]

There was a commit in 2019 that disabled minification of white space inside of var() on purpose: #835. Myabe it was a bit overzealous.