get-blocks-css-v2.js

const add = (list) => (rule) => list.push(rule) && "";
const cssBlock = /([^}{;]*){([^}{]+)}/;
function parse(css) {
    let blocks = [];
    let current;
    while(current = css.match(cssBlock)){
      const [fragment,selector,content] = current;
      const [spaces] = selector.match(/^ */);
      const { index: start } = current;
      const { length } = fragment;
      const end = fragment.length+start;
      const children = [];
      const block = {selector:selector.trim(),content:content.trim(),start:start+spaces.length,end,children};
      blocks = blocks.reduce((blocks,b)=>{
        (block.start < b.start && b.end < block.end ? children : blocks).push(b);
        return blocks;
      },[])
      block.children = children;
      blocks.push(block)
      css = css.slice(0,start)+" ".repeat(length)+css.slice(end);
    }
    return blocks;
}