stdio.test.ts

import { Buffer } from "node:buffer";
import { JSONRPCMessage } from "../types.js";
import { ReadBuffer } from "./stdio.js";

const testMessage: JSONRPCMessage = {
  jsonrpc: "2.0",
  method: "foobar",
};

test("should have no messages after initialization", () => {
  const readBuffer = new ReadBuffer();
  expect(readBuffer.readMessage()).toBeNull();
});

test("should only yield a message after a newline", () => {
  const readBuffer = new ReadBuffer();

  readBuffer.append(Buffer.from(JSON.stringify(testMessage)));
  expect(readBuffer.readMessage()).toBeNull();

  readBuffer.append(Buffer.from("\n"));
  expect(readBuffer.readMessage()).toEqual(testMessage);
  expect(readBuffer.readMessage()).toBeNull();
});

test("should be reusable after clearing", () => {
  const readBuffer = new ReadBuffer();

  readBuffer.append(Buffer.from("foobar"));
  readBuffer.clear();
  expect(readBuffer.readMessage()).toBeNull();

  readBuffer.append(Buffer.from(JSON.stringify(testMessage)));
  readBuffer.append(Buffer.from("\n"));
  expect(readBuffer.readMessage()).toEqual(testMessage);
});