node_modules/stylelint/lib/utils/isStandardSyntaxSelector.js

/* @flow */
"use strict";

const hasInterpolation = require("../utils/hasInterpolation");

/**
 * Check whether a selector is standard
 */
module.exports = function(selector /*: string*/) /*: boolean*/ {
  // SCSS or Less interpolation
  if (hasInterpolation(selector)) {
    return false;
  }

  // SCSS placeholder selectors
  if (selector.indexOf("%") === 0) {
    return false;
  }

  // Less :extend()
  if (/:extend(\(.*?\))?/.test(selector)) {
    return false;
  }

  // Less mixin with resolved nested selectors (e.g. .foo().bar or .foo(@a, @b)[bar])
  if (/\.[a-z0-9-_]+\(.*\).+/i.test(selector)) {
    return false;
  }

  return true;
};