Parses a given CSS rule

CSSRule.js

(function(input) {

  class CSSRule {
    constructor(cssText) {
      this.raw = cssText
      this.parsed = CSSRule.parse(cssText)
      return this
    }
  
    static parse(cssText) {
      var [, selectorsText, declarationsText] = cssText
        .replace(/\n/g, '')
        .match(/(.+)\{(.+)\}/)

      var selectors = selectorsText
        .split(/,/)
        .map(e => e.trim())

      var declarations = declarationsText
        .split(/;/)
        .map(e => e.trim())
        .filter(Boolean)
        .map(e => e.split(/:/).map(p => p.trim()))

      return {
        selectors,
        declarations
      }
    }
  }
  
  return new CSSRule(input)

})(`
  .my-element, body,
  some-custom-element and-its-child {
    color: red;
    background: rgba(255, 25, 5, .4);
    color: blue;
  }
`)