backend/libs/common/src/helper/snakeCaseConverter.ts

function toSnakeCase(str) {
  return str.replace(/([A-Z])/g, '_$1').toLowerCase();
}

export function convertKeysToSnakeCase(obj) {
  if (Array.isArray(obj)) {
    return obj.map((v) => convertKeysToSnakeCase(v));
  } else if (obj !== null && obj.constructor === Object) {
    return Object.keys(obj).reduce((result, key) => {
      const snakeKey = toSnakeCase(key);
      result[snakeKey] = convertKeysToSnakeCase(obj[key]);
      return result;
    }, {});
  }
  return obj;
}