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

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

import cssSelectorParser from 'postcss-selector-parser';
import { getSourceCode } from '@atlaskit/eslint-utils/context-compat';
const cssSelectorProcessor = cssSelectorParser();
const selectorCache = new WeakMap();

/**
 * Parse each selector once per linted source file. Consumers treat the returned AST as read-only.
 */
export function parseSelector(context, selectorText) {
  const sourceCode = getSourceCode(context);
  let sourceFileCache = selectorCache.get(sourceCode);
  if (!sourceFileCache) {
    sourceFileCache = new Map();
    selectorCache.set(sourceCode, sourceFileCache);
  }
  const cachedSelector = sourceFileCache.get(selectorText);
  if (cachedSelector) {
    return cachedSelector;
  }
  const selector = cssSelectorProcessor.astSync(selectorText);
  sourceFileCache.set(selectorText, selector);
  return selector;
}