RabbitMQ amqplib RPC helper class (Reply-to)

Instalation

npm install amqplib

Server side (Provider)

const Provider = require("./provider")

new Provider({
  queue: "example4",
  
  // this function will reply consumers messages
  responseFn: async (message, reply) => {
    switch (message) {
        case "command1":
            return "Hi there!";
        break;
        case "command2":
            return {status: 200};
        break;
        default: 
            return {result: 404, reason: "not found command."};
        break;
    }
  },
}).connect("amqp://localhost");

Note you should use responseFn to reply the answer, if you don't wanna answer, just return nothing.

Client side (Consumer)

const Consumer = require("./consumer")

new Consumer({
  queue: "example4",
}).then((client) => {
  client
    .connect("amqp://localhost")
    .then((client) => {
      return client.send({ text: "hello" });
    })
    .then((response) => {
      console.log(response);
    });
});

Express.js example

npm install express

const express = require("express");
const app = express();
const Consumer = require("./consumer")

app.get("/test", async (req, res) => {
    const client = await new Consumer({
        queue: "example4"
    });
    
    // Send message and receive the answer from provider
    const response = await client.connect("amqp://localhost")
      .then((client) => client.send("hello"))
      .then(res);

    res.send(response);
})

app.listen(3000, () => {
  console.log(`Server is running on port 3000`);
});

Advanced parameters:

• queue: required., Set your queue.
• correlationId: Set correlation ID for receiver.
• replyTo: required. Client to receive reply from provider.
• contentType: "application/json" or "application/textplain", it used for format message, in any case it will do automatically.
• responseType: "application/json" or "application/textplain", it used for format message, in any case it will do automatically.
• connectionAdress: Connection adress, for example: amqp://localhost/