Use interface instead of class

class definition can be replaced by function returning required object interface instance DbAdapter. This is more popular approach compared to define new class and using new

Always try to use functional style !

Sample database adapter with few methods and single property

interface DbAdapter {
  databaseName: string;
  put: (item: string) => void;
  get: (id: string) => string | undefined;
}

Could be created inside of buildDatabaseAdapter which receive “constructor” parameter databaseName Both functions get and put are exposed by interface definition as public.

Within function you could define any other scoped functions, they will remain private.

const buildDatabaseAdapter = (databaseName: string): DbAdapter => {
  const realDatabaseConnector = {} as any;

  // private
  const _getData = (id: string) => realDatabaseConnector.get(id);

  // exposed via return, it is public
  function get(id: string) {
    return _getData(id);
  }
  function put(item: string) {
    // no `this` required here
    return realDatabaseConnector.put(item);
  }

  return {
    databaseName,
    put,
    get,
  };
};
const myDbAdapter: DbAdapter = buildDatabaseAdapter("sample");

Notable advantages: