How to use css-what - 5 common examples

export function selectAll(selector: string, elm: MockElement) {
  const selectors = parse(selector);
  const foundElms: MockElement[] = [];
  selectAllRecursion(selectors, elm, foundElms);
  return foundElms;
}

export function matches(selector: string, elm: MockElement) {
  const selectors = parse(selector);
  return matchesSelectors(selectors, elm) !== null;
}

export function selectOne(selector: string, elm: MockElement) {
  const selectors = parse(selector);
  return selectOneRecursion(selectors, elm);
}

function compileUnsafe(selector, options, context) {
    var token = parse(selector, options);
    return compileToken(token, options, context);
}

output.logs.push({
      reason: 'W:选择器`' + selector + '`不支持',
      line: rule.position.start.line,
      column: rule.position.start.column
    })
    return false
  }
  if (~selector.indexOf(':before') || ~selector.indexOf(':after') || ~selector.indexOf(':last-child') || ~selector.indexOf(':first-child')) {
    output.logs.push({
      reason: 'W:选择器`' + selector + '`不支持',
      line: rule.position.start.line,
      column: rule.position.start.column
    })
    return false
  }
  selector = cssWhat.parse(selector)[0].map(subselect => {
    if (subselect.type === 'descendant') {
      return ' '
    } else if (subselect.type === 'attribute') {
      if (subselect.name === 'class') {
        return '.' + subselect.value
      } else if (subselect.name === 'id') {
        return '#' + subselect.value
      }
    }
    return ''
  }).join('')
  return selector
}