terse_example.ts

// in the handler NS we have our microservice
// which is an AWS Lambda
export const usersPublicGet = async (event: requests.MinimalRequestEvent): Promise<responses.Response> => {
  const system: db.System = await db.getSystem();
  const client = system.pgclient;

  try {

    const response = await p.pipeline(event, up.getPublicPipeline)(system)();
    return response;

  } catch (err) {
    console.log(err);
    return responses.respond500('http/error', 'Something went wrong');
  } finally {
    await db.closeDbConn(client);
  }
}; 

// in the up (users pipeline) namespace we have lots of Do chains
// of RTE - ReaderTaskEither - monads
const getPublicPipeline = (event: requests.MinimalRequestEvent): RTE.ReaderTaskEither<db.System, t.ErrorType, t.EntityType> =>
  Do(RTE.readerTaskEither)
    .bind('userId', RTE.fromEither(requests.getIdFromPath(event)))
    .bindL('getUserRes', ({ userId }) => uDb.getUserRTE(userId))
    .bindL('user', ({ getUserRes }) => RTE.fromEither(uXfms.getUserFromResE(getUserRes)))
    .bindL('userNoPII', ({ user }) => RTE.fromEither(uXfms.userToShareableE(user)))
    .bindL('getUserFileRes', ({ user }) => fDb.getFileRTE(user.file_uuid))
    .bindL('userFile', ({ getUserFileRes }) => RTE.right(fXfms.getUserFileDataFromRes(getUserFileRes)))
    .bindL('userNoPIIWithFile', ({ userNoPII, userFile }) => RTE.right(R.mergeRight(userNoPII, { file: userFile })))
    .return(({ userNoPIIWithFile }) => { return { entityType: t.EntityTypes.user, entity: userNoPIIWithFile }; });