@nestjstools/messaging/lib/middleware/handler-middleware.js

Simplifies asynchronous and synchronous message handling with support for buses, handlers, channels, and consumers. Build scalable, decoupled applications with ease and reliability.

"use strict";
var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
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    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
    return c > 3 && r && Object.defineProperty(target, key, r), r;
};
var __metadata = (this && this.__metadata) || function (k, v) {
    if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
};
var __param = (this && this.__param) || function (paramIndex, decorator) {
    return function (target, key) { decorator(target, key, paramIndex); }
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.HandlerMiddleware = void 0;
const message_handler_registry_1 = require("../handler/message-handler.registry");
const common_1 = require("@nestjs/common");
const service_1 = require("../dependency-injection/service");
const decorator_1 = require("../dependency-injection/decorator");
const log_1 = require("../logger/log");
const handlers_exception_1 = require("../exception/handlers.exception");
const class_transformer_1 = require("class-transformer");
let HandlerMiddleware = class HandlerMiddleware {
    constructor(handlerRegistry, logger) {
        this.handlerRegistry = handlerRegistry;
        this.logger = logger;
    }
    async process(message, context) {
        const handlers = this.handlerRegistry.getByRoutingKey(message.messageRoutingKey);
        return this.handleParallel(message, handlers);
    }
    async handleParallel(message, handlers) {
        const errors = [];
        if (1 === handlers.length) {
            const handler = handlers[0];
            this.logHandlerMessage(handler.constructor.name, message.messageRoutingKey);
            try {
                const result = await handler.handle(this.convertToInstance(handler, message.message));
                return Promise.resolve(result);
            }
            catch (error) {
                const exception = new handlers_exception_1.HandlersException([
                    new handlers_exception_1.HandlerError(handler.constructor.name, error),
                ]);
                this.logHandlerErrorMessage(handler.constructor.name, message, exception);
                return Promise.reject(exception);
            }
        }
        const results = await Promise.allSettled(handlers.map((handler) => {
            try {
                this.logHandlerMessage(handler.constructor.name, message.messageRoutingKey);
                return handler.handle(this.convertToInstance(handler, message.message));
            }
            catch (err) {
                return Promise.reject({
                    handler: handler.constructor.name,
                    error: err,
                });
            }
        }));
        for (const result of results) {
            if (result.status === 'rejected') {
                const exception = result.reason.error;
                this.logHandlerErrorMessage(result.reason.handler, message, exception);
                errors.push(new handlers_exception_1.HandlerError(result.reason.handler, exception));
            }
        }
        if (errors.length > 0) {
            throw new handlers_exception_1.HandlersException(errors);
        }
        return Promise.resolve(null);
    }
    convertToInstance(handler, message) {
        const instance = Reflect.getMetadata('design:paramtypes', handler, 'handle');
        if (!instance) {
            return message;
        }
        return (0, class_transformer_1.plainToInstance)(instance[0], message);
    }
    logHandlerMessage(handler, messageRoutingKey) {
        this.logger.debug(log_1.Log.create(`Found a handler [${handler}] for message [${messageRoutingKey}]`));
    }
    logHandlerErrorMessage(handler, message, exception) {
        this.logger.error(log_1.Log.create(`Some error occurred in Handler [${handler}]`, {
            error: exception.message,
            exception,
            message: JSON.stringify(message.message),
        }));
    }
};
exports.HandlerMiddleware = HandlerMiddleware;
exports.HandlerMiddleware = HandlerMiddleware = __decorate([
    (0, common_1.Injectable)(),
    (0, decorator_1.MessagingMiddleware)(),
    __param(0, (0, common_1.Inject)(service_1.Service.MESSAGE_HANDLERS_REGISTRY)),
    __param(1, (0, common_1.Inject)(service_1.Service.LOGGER)),
    __metadata("design:paramtypes", [message_handler_registry_1.MessageHandlerRegistry, Object])
], HandlerMiddleware);
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