bun.sh/test/bun.js/websocket.test.js

import { describe, it, expect } from "bun:test";
import { unsafe } from "bun";
import { gc } from "./gc";

const TEST_WEBSOCKET_HOST =
  process.env.TEST_WEBSOCKET_HOST || "wss://ws.postman-echo.com/raw";

describe("WebSocket", () => {
  it("should connect", async () => {
    const ws = new WebSocket(TEST_WEBSOCKET_HOST);
    await new Promise((resolve, reject) => {
      ws.onopen = resolve;
      ws.onerror = reject;
    });
    var closed = new Promise((resolve, reject) => {
      ws.onclose = resolve;
    });
    ws.close();
    await closed;
  });

  it("should send and receive messages", async () => {
    const ws = new WebSocket(TEST_WEBSOCKET_HOST);
    await new Promise((resolve, reject) => {
      ws.onopen = resolve;
      ws.onerror = reject;
      ws.onclose = () => {
        reject("WebSocket closed");
      };
    });
    const count = 10;

    // 10 messages in burst
    var promise = new Promise((resolve, reject) => {
      var remain = count;
      ws.onmessage = (event) => {
        gc(true);
        expect(event.data).toBe("Hello World!");
        remain--;

        if (remain <= 0) {
          ws.onmessage = () => {};
          resolve();
        }
      };
      ws.onerror = reject;
    });

    for (let i = 0; i < count; i++) {
      ws.send("Hello World!");
      gc(true);
    }

    await promise;
    var echo = 0;

    // 10 messages one at a time
    function waitForEcho() {
      return new Promise((resolve, reject) => {
        gc(true);
        const msg = `Hello World! ${echo++}`;
        ws.onmessage = (event) => {
          expect(event.data).toBe(msg);
          resolve();
        };
        ws.onerror = reject;
        ws.onclose = reject;
        ws.send(msg);
        gc(true);
      });
    }
    gc(true);
    for (let i = 0; i < count; i++) await waitForEcho();
    ws.onclose = () => {};
    ws.onerror = () => {};
    ws.close();
    gc(true);
  });
});