@nestjs/microservices/decorators/event-pattern.decorator.js

Nest - modern, fast, powerful node.js web framework (@microservices)

import { PATTERN_EXTRAS_METADATA, PATTERN_HANDLER_METADATA, PATTERN_METADATA, TRANSPORT_METADATA, } from '../constants.js';
import { PatternHandler } from '../enums/pattern-handler.enum.js';
import { isNil, isNumber, isObject, isSymbol } from '@nestjs/common/internal';
/**
 * Subscribes to incoming events which fulfils chosen pattern.
 *
 * @publicApi
 */
export const EventPattern = (metadata, transportOrExtras, maybeExtras) => {
    let transport;
    let extras;
    if ((isNumber(transportOrExtras) || isSymbol(transportOrExtras)) &&
        isNil(maybeExtras)) {
        transport = transportOrExtras;
    }
    else if (isObject(transportOrExtras) && isNil(maybeExtras)) {
        extras = transportOrExtras;
    }
    else {
        transport = transportOrExtras;
        extras = maybeExtras;
    }
    return (target, key, descriptor) => {
        Reflect.defineMetadata(PATTERN_METADATA, [].concat(metadata), descriptor.value);
        Reflect.defineMetadata(PATTERN_HANDLER_METADATA, PatternHandler.EVENT, descriptor.value);
        Reflect.defineMetadata(TRANSPORT_METADATA, transport, descriptor.value);
        Reflect.defineMetadata(PATTERN_EXTRAS_METADATA, {
            ...Reflect.getMetadata(PATTERN_EXTRAS_METADATA, descriptor.value),
            ...extras,
        }, descriptor.value);
        return descriptor;
    };
};