Function createEngineStream

src/jrpc/jrpcEngine.ts:426–463

(opts: EngineStreamOptions)

 * @deprecated Use {@link createEngineStreamV2} instead.
 */
export function createEngineStream(opts: EngineStreamOptions): Duplex {
  if (!opts || !opts.engine) {
    throw new Error("Missing engine parameter!");
  }

  const { engine } = opts;
  // eslint-disable-next-line prefer-const
  let stream: Duplex;

  function read(): undefined {
    return undefined;
  }

  function write(req: JRPCRequest, _encoding: unknown, cb: (error?: Error | null) => void) {
    engine.handle(req, (_err, res) => {
      stream.push(res);
    });
    cb();
  }

  stream = new Duplex({ objectMode: true, read, write });

  // forward notifications
  if (engine.on) {
    const onNotification = (message: unknown) => {
      stream.push(message);
    };

    // cleanup listener on stream close
    const cleanup = () => {
      engine.removeListener("notification", onNotification);
    };

    engine.on("notification", onNotification);
    stream.once("close", cleanup);
  }
  return stream;
}

/**
 * @deprecated Use {@link providerFromEngineV2} instead.