@rxap/nest-rabbitmq/src/lib/client-rmq-exchange.js

This package provides a NestJS module for integrating with RabbitMQ using exchanges. It offers a client and server implementation for message queuing and supports features like health checks and error serialization. It simplifies the process of setting up

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.ClientRMQExchange = exports.REPLY_QUEUE = void 0;
const logger_service_1 = require("@nestjs/common/services/logger.service");
const random_string_generator_util_1 = require("@nestjs/common/utils/random-string-generator.util");
const shared_utils_1 = require("@nestjs/common/utils/shared.utils");
const microservices_1 = require("@nestjs/microservices");
const constants_1 = require("@nestjs/microservices/constants");
const serializers_1 = require("@nestjs/microservices/serializers");
const amqp_connection_manager_1 = require("amqp-connection-manager");
const events_1 = require("events");
const rxjs_1 = require("rxjs");
const operators_1 = require("rxjs/operators");
const incoming_response_deserializer_1 = require("./incoming-response.deserializer");
exports.REPLY_QUEUE = 'amq.rabbitmq.reply-to';
class ClientRMQExchange extends microservices_1.ClientProxy {
    constructor(options, logger = new logger_service_1.Logger(microservices_1.ClientProxy.name)) {
        super();
        this.options = options;
        this.logger = logger;
        this.client = null;
        this.channel = null;
        this.initializeSerializer(options);
        this.initializeDeserializer(options);
    }
    isConnected() {
        return this.client && this.client.isConnected();
    }
    close() {
        this.channel && this.channel.close();
        this.client && this.client.close();
        this.channel = null;
        this.client = null;
    }
    connect() {
        if (this.client) {
            return this.convertConnectionToPromise();
        }
        this.client = this.createClient();
        this.handleError(this.client);
        this.handleDisconnectError(this.client);
        this.responseEmitter = new events_1.EventEmitter();
        this.responseEmitter.setMaxListeners(0);
        const connect$ = this.connect$(this.client);
        const withDisconnect$ = this.mergeDisconnectEvent(this.client, connect$).pipe((0, rxjs_1.tap)(() => this.createChannel()));
        const withReconnect$ = (0, rxjs_1.fromEvent)(this.client, constants_1.CONNECT_EVENT).pipe((0, rxjs_1.tap)(() => this.logger.log('Connected to RMQ', 'ClientRMQExchange')), (0, operators_1.skip)(1));
        const source$ = (0, rxjs_1.merge)(withDisconnect$, withReconnect$);
        this.connection$ = new rxjs_1.ReplaySubject(1);
        source$.subscribe({
            next: data => {
                this.connection$.next(data.connection);
            },
        });
        return this.convertConnectionToPromise();
    }
    createChannel() {
        return new Promise(resolve => {
            this.channel = this.client.createChannel({
                json: false,
                setup: (channel) => this.setupExchange(channel, resolve),
            });
        });
    }
    createClient() {
        const socketOptions = this.getOptionsProp(this.options, 'socketOptions');
        return (0, amqp_connection_manager_1.connect)(this.options.urls, socketOptions);
    }
    mergeDisconnectEvent(instance, source$) {
        const eventToError = (eventType) => (0, rxjs_1.fromEvent)(instance, eventType).pipe((0, operators_1.map)((err) => {
            this.logger.error(`Error occurred for event type "${eventType}": ${err.message}`, err.stack, 'ClientRMQExchange');
            throw err;
        }));
        const disconnect$ = eventToError(constants_1.DISCONNECT_EVENT);
        const urls = this.getOptionsProp(this.options, 'urls', []) ?? [];
        const connectFailed$ = eventToError(constants_1.CONNECT_FAILED_EVENT).pipe((0, operators_1.retryWhen)(e => e.pipe((0, operators_1.scan)((errorCount, error) => {
            if (urls.indexOf(error.url) >= urls.length - 1) {
                throw error;
            }
            return errorCount + 1;
        }, 0))));
        // If we ever decide to propagate all disconnect errors & re-emit them through
        // the "connection" stream then comment out "first()" operator.
        return (0, rxjs_1.merge)(source$, disconnect$, connectFailed$).pipe((0, operators_1.first)());
    }
    async convertConnectionToPromise() {
        // try {
        return await (0, rxjs_1.firstValueFrom)(this.connection$);
        // } catch (err) {
        //   if (err instanceof EmptyError) {
        //     return;
        //   }
        //   throw err;
        // }
    }
    async setupExchange(channel, resolve) {
        this.logger.verbose(`Setting up exchange '${this.options.exchange.name}'`, 'ClientRMQExchange');
        if (!this.options.noAssert) {
            await channel.assertExchange(this.options.exchange.name, this.options.exchange.type, this.options.exchange.options);
        }
        await this.consumeChannel(channel);
        resolve();
    }
    async consumeChannel(channel) {
        const noAck = this.getOptionsProp(this.options, 'noAck', constants_1.RQM_DEFAULT_NOACK);
        await channel.consume(this.options.replyQueue ?? exports.REPLY_QUEUE, (msg) => {
            if (msg) {
                this.responseEmitter.emit(msg.properties.correlationId, msg);
            }
            else {
                this.logger.warn(`Message is empty from RMQ queue ${this.options.replyQueue ?? exports.REPLY_QUEUE}`, 'ClientRMQExchange');
            }
        }, {
            noAck,
        });
    }
    handleError(client) {
        client.addListener(constants_1.ERROR_EVENT, (err) => this.logger.error(err, undefined, 'ClientRMQExchange'));
    }
    handleDisconnectError(client) {
        client.addListener(constants_1.DISCONNECT_EVENT, (err) => {
            this.logger.error(constants_1.DISCONNECTED_RMQ_MESSAGE, undefined, 'ClientRMQExchange');
            this.logger.error(err, undefined, 'ClientRMQExchange');
        });
    }
    async handleMessage(packet, optionsOrCallback, callback) {
        this.logger.verbose('Received message: %JSON', packet, 'ClientRMQExchange');
        let options = undefined;
        if ((0, shared_utils_1.isFunction)(options)) {
            callback = options;
        }
        else {
            options = optionsOrCallback;
        }
        if (!callback) {
            throw new Error('No callback provided');
        }
        const { err, response, isDisposed, } = await this.deserializer.deserialize(packet, options);
        // this.logger.verbose('Deserialized response: %JSON', response, 'ClientRMQExchange');
        if (err) {
            this.logger.verbose('Deserialized error: %JSON', err, 'ClientRMQExchange');
        }
        // this.logger.verbose('Deserialized isDisposed: %JSON', isDisposed, 'ClientRMQExchange');
        if (isDisposed || err) {
            callback({
                err,
                response,
                isDisposed: true,
            });
        }
        callback({
            err,
            response,
        });
    }
    publish(message, callback) {
        this.logger.verbose('Publishing message: %JSON', message, 'ClientRMQExchange');
        try {
            const correlationId = (0, random_string_generator_util_1.randomStringGenerator)();
            const listener = ({ content, fields, properties, }) => this.handleMessage(this.parseMessageContent(content), {
                fields,
                properties,
            }, callback);
            Object.assign(message, { id: correlationId });
            const serializedPacket = this.serializer.serialize(message);
            const options = serializedPacket.options;
            delete serializedPacket.options;
            this.responseEmitter.on(correlationId, listener);
            this.channel
                .publish(this.options.exchange.name, serializedPacket.pattern, Buffer.from(JSON.stringify(serializedPacket.data)), {
                replyTo: this.options.replyQueue ?? exports.REPLY_QUEUE,
                persistent: this.options.persistent,
                ...options,
                headers: this.mergeHeaders(options?.headers),
                correlationId,
            })
                .catch(err => callback({ err }));
            return () => this.responseEmitter.removeListener(correlationId, listener);
        }
        catch (err) {
            callback({ err });
        }
        return () => void 0;
    }
    dispatchEvent(packet) {
        this.logger.verbose('Dispatching event: %JSON', packet, 'ClientRMQExchange');
        const serializedPacket = this.serializer.serialize(packet);
        const options = serializedPacket.options;
        delete serializedPacket.options;
        return new Promise((resolve, reject) => this.channel.publish(this.options.exchange.name, serializedPacket.pattern, Buffer.from(JSON.stringify(serializedPacket.data)), {
            persistent: this.options.persistent,
            ...options,
            headers: this.mergeHeaders(options?.headers),
        }, (err) => (err ? reject(err) : resolve())));
    }
    initializeSerializer(options) {
        this.serializer = options.serializer ?? new serializers_1.RmqRecordSerializer();
    }
    initializeDeserializer(options) {
        this.deserializer = options.deserializer ?? new incoming_response_deserializer_1.IncomingResponseDeserializer();
    }
    mergeHeaders(requestHeaders) {
        if (!requestHeaders && !this.options?.headers) {
            return undefined;
        }
        return {
            ...this.options?.headers,
            ...requestHeaders,
        };
    }
    parseMessageContent(content) {
        const rawContent = content.toString();
        try {
            return JSON.parse(rawContent);
        }
        catch {
            return rawContent;
        }
    }
}
exports.ClientRMQExchange = ClientRMQExchange;