renovate/lib/workers/repository/init/flatten.js

const { logger } = require('../../../logger');
const { mergeChildConfig } = require('../../../config');

function flattenPackageRules(packageRules) {
  const res = [];
  if (!(packageRules && packageRules.length)) {
    return res;
  }
  for (const rule of packageRules) {
    if (rule.packageRules && rule.packageRules.length) {
      logger.info('Flattening nested packageRules');
      for (const subrule of rule.packageRules) {
        const combinedRule = mergeChildConfig(rule, subrule);
        delete combinedRule.packageRules;
        res.push(combinedRule);
      }
    } else {
      res.push(rule);
    }
  }
  return res;
}

module.exports = {
  flattenPackageRules,
};