messaging testing

I have generated a Node.js integration testing pattern using ioredis and testcontainers. This setup includes container lifecycle management and a sample pub/sub test case.

Redis Pub/Sub Node.js Test Pattern

import { GenericContainer, StartedTestContainer } from "testcontainers";
import Redis from "ioredis";

describe("Redis Pub/Sub Integration", () => {
  let container: StartedTestContainer;
  let publisher: Redis;
  let subscriber: Redis;

  beforeAll(async () => {
    // Start Redis 7 container
    container = await new GenericContainer("redis:7-alpine")
      .withExposedPorts(6379)
      .start();

    const host = container.getHost();
    const port = container.getMappedPort(6379);
    const url = `redis://${host}:${port}`;

    publisher = new Redis(url);
    subscriber = new Redis(url);
  }, 30000);

  afterAll(async () => {
    if (publisher) await publisher.quit();
    if (subscriber) await subscriber.quit();
    if (container) await container.stop();
  });

  it("should successfully transmit messages between publisher and subscriber", async () => {
    const channel = "test-channel";
    const testMessage = { event: "ORDER_CREATED", id: "123" };
    const receivedMessages: string[] = [];

    // Setup subscription
    await subscriber.subscribe(channel);
    subscriber.on("message", (ch, msg) => {
      if (ch === channel) {
        receivedMessages.push(msg);
      }
    });

    // Publish message
    await publisher.publish(channel, JSON.stringify(testMessage));

    // Wait for async delivery
    await new Promise((resolve) => setTimeout(resolve, 500));

    expect(receivedMessages).toHaveLength(1);
    expect(JSON.parse(receivedMessages[0])).toEqual(testMessage);
  });
});

Next steps

1. Install dependencies: npm install ioredis testcontainers --save-dev.
2. Ensure Docker is running in your environment.
3. Add the test file to your jest or vitest configuration.