@atlaskit/eslint-plugin-ui-styling-standard/dist/es2019/rules/utils/is-simple-selector.js

The eslint plugin to enforce and educate on Atlassian's UI Styling Standard

/**
 * Recognizes simple, parseable selector lists made only from nesting and non-functional pseudos.
 * Returning false means the caller must use the full selector parser.
 */
export function isSimpleSelector(selectorText, options = {}) {
  let index = 0;
  while (index < selectorText.length) {
    index = skipWhitespace(selectorText, index);
    const hasNesting = selectorText.charCodeAt(index) === 38;
    if (hasNesting) {
      index++;
      if (selectorText.charCodeAt(index) === 38) {
        return false;
      }
    } else if (!options.allowLeadingPseudo || selectorText.charCodeAt(index) !== 58) {
      return false;
    }
    let pseudoCount = 0;
    while (selectorText.charCodeAt(index) === 58) {
      const pseudoStart = index++;
      if (selectorText.charCodeAt(index) === 58) {
        index++;
      }
      const nameStart = index;
      while (index < selectorText.length && isPseudoNameCharacter(selectorText.charCodeAt(index))) {
        index++;
      }
      if (index === nameStart || selectorText.charCodeAt(index) === 40) {
        return false;
      }
      if (options.allowedPseudos && !options.allowedPseudos.has(selectorText.slice(pseudoStart, index))) {
        return false;
      }
      pseudoCount++;
    }
    if (pseudoCount === 0 && (!hasNesting || !options.allowBareNesting)) {
      return false;
    }
    index = skipWhitespace(selectorText, index);
    if (index === selectorText.length) {
      return true;
    }
    if (selectorText.charCodeAt(index) !== 44) {
      return false;
    }
    index++;
  }
  return false;
}
function skipWhitespace(value, start) {
  let index = start;
  while (index < value.length) {
    const character = value.charCodeAt(index);
    if (character !== 32 && (character < 9 || character > 13)) {
      break;
    }
    index++;
  }
  return index;
}
function isPseudoNameCharacter(character) {
  return character === 45 || character === 95 || character >= 48 && character <= 57 || character >= 65 && character <= 90 || character >= 97 && character <= 122;
}