Custom visitor transformation doesn't get minified

[webschik]

Hi,

First of all, thank you for the amazing tool!

During my attempt to implement a customer visitor to inline "static" CSS variables, similar to the behaviour of postcss-custom-properties plugin, I found that the result of custom visitor doesn't get minified correctly:

Input

.foo {
  width: calc(20 * var(--grid));
}

// visitor
{
  Variable(variable) {
    if (variable.name.ident === '--grid') {
      return {type: 'length', value: {unit: 'rem', value: 0.25}}
    }
  }
}

Actual output

.foo{width:calc(20*.25rem)}

Expected output

.foo{width:5rem}

Playground link

[webschik]

Btw, I found another issue related to the value replacement, please check this example.

Maybe it's not a bug, but may incorrect understanding of how the transformation should work...
Please, help me to figure our what goes wrong, when you have time.

[devongovett]

calc simplification happens during the initial parse phase, which is before custom visitors run. Currently there is not an additional simplification pass done after transforms, resulting in the output you see here.

[webschik]

Thanks @devongovett!
Is this behavior strictly defined and won't change in the future?
And could you please check the 2nd issue, this example, as well?

[robertmoura]

I ran into that second bug as well. I've created an issue here: #579